@misc{DelfanVahedBishopetal.2022, author = {Delfan, Maryam and Vahed, Alieh and Bishop, David and Juybari, Raheleh Amadeh and Laher, Ismail and Saeidi, Ayoub and Granacher, Urs and Zouhal, Hassane}, title = {Effects of two workload-matched high intensity interval training protocols on regulatory factors associated with mitochondrial biogenesis in the soleus muscle of diabetic rats}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-56444}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-564441}, pages = {1 -- 12}, year = {2022}, abstract = {Aims: High intensity interval training (HIIT) improves mitochondrial characteristics. This study compared the impact of two workload-matched high intensity interval training (HIIT) protocols with different work:recovery ratios on regulatory factors related to mitochondrial biogenesis in the soleus muscle of diabetic rats. Materials and methods: Twenty-four Wistar rats were randomly divided into four equal-sized groups: non-diabetic control, diabetic control (DC), diabetic with long recovery exercise [4-5 × 2-min running at 80\%-90\% of the maximum speed reached with 2-min of recovery at 40\% of the maximum speed reached (DHIIT1:1)], and diabetic with short recovery exercise (5-6 × 2-min running at 80\%-90\% of the maximum speed reached with 1-min of recovery at 30\% of the maximum speed reached [DHIIT2:1]). Both HIIT protocols were completed five times/week for 4 weeks while maintaining equal running distances in each session. Results: Gene and protein expressions of PGC-1α, p53, and citrate synthase of the muscles increased significantly following DHIIT1:1 and DHIIT2:1 compared to DC (p ˂ 0.05). Most parameters, except for PGC-1α protein (p = 0.597), were significantly higher in DHIIT2:1 than in DHIIT1:1 (p ˂ 0.05). Both DHIIT groups showed significant increases in maximum speed with larger increases in DHIIT2:1 compared with DHIIT1:1. Conclusion: Our findings indicate that both HIIT protocols can potently up-regulate gene and protein expression of PGC-1α, p53, and CS. However, DHIIT2:1 has superior effects compared with DHIIT1:1 in improving mitochondrial adaptive responses in diabetic rats.}, language = {en} } @misc{JafarnezhadgeroAmirzadehFatollahietal.2022, author = {Jafarnezhadgero, Amir Ali and Amirzadeh, Nasrin and Fatollahi, Amir and Siahkouhian, Marefat and de Souza Castelo Oliveira, Anderson and Granacher, Urs}, title = {Effects of running on sand vs. stable ground on kinetics and muscle activities in individuals with over-pronated feet}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-55756}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-557567}, pages = {1 -- 10}, year = {2022}, abstract = {Background: In terms of physiological and biomechanical characteristics, over-pronation of the feet has been associated with distinct muscle recruitment patterns and ground reaction forces during running. Objective: The aim of this study was to evaluate the effects of running on sand vs. stable ground on ground-reaction-forces (GRFs) and electromyographic (EMG) activity of lower limb muscles in individuals with over-pronated feet (OPF) compared with healthy controls. Methods: Thirty-three OPF individuals and 33 controls ran at preferred speed and in randomized-order over level-ground and sand. A force-plate was embedded in an 18-m runway to collect GRFs. Muscle activities were recorded using an EMG-system. Data were adjusted for surface-related differences in running speed. Results: Running on sand resulted in lower speed compared with stable ground running (p < 0.001; d = 0.83). Results demonstrated that running on sand produced higher tibialis anterior activity (p = 0.024; d = 0.28). Also, findings indicated larger loading rates (p = 0.004; d = 0.72) and greater vastus medialis (p < 0.001; d = 0.89) and rectus femoris (p = 0.001; d = 0.61) activities in OPF individuals. Controls but not OPF showed significantly lower gluteus-medius activity (p = 0.022; d = 0.63) when running on sand. Conclusion: Running on sand resulted in lower running speed and higher tibialis anterior activity during the loading phase. This may indicate alterations in neuromuscular demands in the distal part of the lower limbs when running on sand. In OPF individuals, higher loading rates together with greater quadriceps activity may constitute a proximal compensatory mechanism for distal surface instability.}, language = {en} } @misc{DelfanJuybariGorganiFiruzjaeeetal.2022, author = {Delfan, Maryam and Juybari, Raheleh Amadeh and Gorgani-Firuzjaee, Sattar and Nielsen, Jens H{\o}iriis and Delfan, Neda and Laher, Ismail and Saeidi, Ayoub and Granacher, Urs and Zouhal, Hassane}, title = {High-Intensity Interval Training Improves Cardiac Function by miR-206 Dependent HSP60 Induction in Diabetic Rats}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {802}, issn = {1866-8364}, doi = {10.25932/publishup-56723}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-567238}, pages = {11}, year = {2022}, abstract = {Objective: A role for microRNAs is implicated in several biological and pathological processes. We investigated the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on molecular markers of diabetic cardiomyopathy in rats. Methods: Eighteen male Wistar rats (260 ± 10 g; aged 8 weeks) with streptozotocin (STZ)-induced type 1 diabetes mellitus (55 mg/kg, IP) were randomly allocated to three groups: control, MICT, and HIIT. The two different training protocols were performed 5 days each week for 5 weeks. Cardiac performance (end-systolic and end-diastolic dimensions, ejection fraction), the expression of miR-206, HSP60, and markers of apoptosis (cleaved PARP and cytochrome C) were determined at the end of the exercise interventions. Results: Both exercise interventions (HIIT and MICT) decreased blood glucose levels and improved cardiac performance, with greater changes in the HIIT group (p < 0.001, η2: 0.909). While the expressions of miR-206 and apoptotic markers decreased in both training protocols (p < 0.001, η2: 0.967), HIIT caused greater reductions in apoptotic markers and produced a 20\% greater reduction in miR-206 compared with the MICT protocol (p < 0.001). Furthermore, both training protocols enhanced the expression of HSP60 (p < 0.001, η2: 0.976), with a nearly 50\% greater increase in the HIIT group compared with MICT. Conclusions: Our results indicate that both exercise protocols, HIIT and MICT, have the potential to reduce diabetic cardiomyopathy by modifying the expression of miR-206 and its downstream targets of apoptosis. It seems however that HIIT is even more effective than MICT to modulate these molecular markers.}, language = {en} } @misc{JafarnezhadgeroFakhriGranacher2021, author = {Jafarnezhadgero, Amir Ali and Fakhri, Ehsan and Granacher, Urs}, title = {Effects of nail softness and stiffness with distance running shoes on ground reaction forces and vertical loading rates in male elite long-distance runners with pronated feet}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, volume = {13}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-55027}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-550274}, pages = {1 -- 9}, year = {2021}, abstract = {Background To improve propulsion during running, athletes often wear spike shoes designed for training and/or competition. Running with spike shoes may cause pain and/or injuries. To address this problem, a modified spike shoe was tested. This study aimed to evaluate the effects of running with dual-versus single-stiffness spike running shoes on running mechanics in long-distance runners with pronated feet. Methods Sixteen male elite (national competitive level) runners (5000 or 10,000 m) aged 28.2 ± 2.5 years with pronated feet volunteered to participate in this study. To be included, participants had to have achieved personal best race times over 5- and/or 10-km races under 17 or 34 min during official running competitions. All participants were heel strikers and had a history of 11.2 ± 4.2 years of training. For the assessment of running kinetics, a force plate was imbedded into a walkway. Running kinematics were recorded using a Vicon-motion-capture system. Nike Zoom Rival shoes (Nike, Nike Zoom Rival, USA) were selected and adapted according to spike softness and stiffness. Participants ran at a constant speed of ~4.0 m/s across the walkway with both shoe conditions in randomized order. Six trials were recorded per condition. The main outcomes included peak ground reaction forces and their time-to-peak, average and instantaneous vertical loading rates, free moments, and peak ankle eversion angles. Results Paired t-tests revealed significantly lower lateral (p = 0.021, d = 0.95) and vertical (p = 0.010, d = 1.40) forces at heel contact during running with dual-stiffness spike shoes. Running with dual-stiffness spike shoes resulted in a significantly longer time-to-peak vertical (p = 0.004, d = 1.40) force at heel contact. The analysis revealed significantly lower average (p = 0.005, d = 0.46) and instantaneous (p = 0.021, d = 0.49) loading rates and peak negative free moment amplitudes (p = 0.016, d = 0.81) when running with dual-stiffness spike shoes. Finally, significantly lower peak ankle eversion angles were observed with dual-stiffness spike shoes (p < 0.001, d = 1.29). Conclusions Running in dual- compared with single-stiffness spike distance running shoes resulted in lower loading rates, free moment amplitudes, and peak ankle eversion angles of long-distance runners with pronated feet.}, language = {en} } @misc{RamachandranSinghRamirezCampilloetal.2021, author = {Ramachandran, Akhilesh Kumar and Singh, Utkarsh and Ramirez-Campillo, Rodrigo and Clemente, Filipe Manuel and Afonso, Jos{\´e} and Granacher, Urs}, title = {Effects of Plyometric Jump Training on Balance Performance in Healthy Participants: A Systematic Review With Meta-Analysis / Effects of plyometric-jump training on balance performance in healthy individuals across the lifespan: A systematic review with meta-analysisist}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, issn = {1866-8364}, doi = {10.25932/publishup-52403}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-524034}, pages = {24}, year = {2021}, abstract = {Postural balance represents a fundamental movement skill for the successful performance of everyday and sport-related activities. There is ample evidence on the effectiveness of balance training on balance performance in athletic and non-athletic population. However, less is known on potential transfer effects of other training types, such as plyometric jump training (PJT) on measures of balance. Given that PJT is a highly dynamic exercise mode with various forms of jump-landing tasks, high levels of postural control are needed to successfully perform PJT exercises. Accordingly, PJT has the potential to not only improve measures of muscle strength and power but also balance. To systematically review and synthetize evidence from randomized and non-randomized controlled trials regarding the effects of PJT on measures of balance in apparently healthy participants. Systematic literature searches were performed in the electronic databases PubMed, Web of Science, and SCOPUS. A PICOS approach was applied to define inclusion criteria, (i) apparently healthy participants, with no restrictions on their fitness level, sex, or age, (ii) a PJT program, (iii) active controls (any sport-related activity) or specific active controls (a specific exercise type such as balance training), (iv) assessment of dynamic, static balance pre- and post-PJT, (v) randomized controlled trials and controlled trials. The methodological quality of studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. This meta-analysis was computed using the inverse variance random-effects model. The significance level was set at p <0.05. The initial search retrieved 8,251 plus 23 records identified through other sources. Forty-two articles met our inclusion criteria for qualitative and 38 for quantitative analysis (1,806 participants [990 males, 816 females], age range 9-63 years). PJT interventions lasted between 4 and 36 weeks. The median PEDro score was 6 and no study had low methodological quality (≤3). The analysis revealed significant small effects of PJT on overall (dynamic and static) balance (ES = 0.46; 95\% CI = 0.32-0.61; p < 0.001), dynamic (e.g., Y-balance test) balance (ES = 0.50; 95\% CI = 0.30-0.71; p < 0.001), and static (e.g., flamingo balance test) balance (ES = 0.49; 95\% CI = 0.31-0.67; p < 0.001). The moderator analyses revealed that sex and/or age did not moderate balance performance outcomes. When PJT was compared to specific active controls (i.e., participants undergoing balance training, whole body vibration training, resistance training), both PJT and alternative training methods showed similar effects on overall (dynamic and static) balance (p = 0.534). Specifically, when PJT was compared to balance training, both training types showed similar effects on overall (dynamic and static) balance (p = 0.514). Conclusion: Compared to active controls, PJT showed small effects on overall balance, dynamic and static balance. Additionally, PJT produced similar balance improvements compared to other training types (i.e., balance training). Although PJT is widely used in athletic and recreational sport settings to improve athletes' physical fitness (e.g., jumping; sprinting), our systematic review with meta-analysis is novel in as much as it indicates that PJT also improves balance performance. The observed PJT-related balance enhancements were irrespective of sex and participants' age. Therefore, PJT appears to be an adequate training regime to improve balance in both, athletic and recreational settings.}, language = {en} } @misc{JararnezhadgeroMamashliGranacher2021, author = {Jararnezhadgero, AmirAli and Mamashli, Elaheh and Granacher, Urs}, title = {An Endurance-Dominated Exercise Program Improves Maximum Oxygen Consumption, Ground Reaction Forces, and Muscle Activities in Patients With Moderate Diabetic Neuropathy}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-54118}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-541182}, pages = {1 -- 15}, year = {2021}, abstract = {Background: The prevalence of diabetes worldwide is predicted to increase from 2.8\% in 2000 to 4.4\% in 2030. Diabetic neuropathy (DN) is associated with damage to nerve glial cells, their axons, and endothelial cells leading to impaired function and mobility. Objective: We aimed to examine the effects of an endurance-dominated exercise program on maximum oxygen consumption (VO2max), ground reaction forces, and muscle activities during walking in patients with moderate DN. Methods: Sixty male and female individuals aged 45-65 years with DN were randomly assigned to an intervention (IG, n = 30) or a waiting control (CON, n = 30) group. The research protocol of this study was registered with the Local Clinical Trial Organization (IRCT20200201046326N1). IG conducted an endurance-dominated exercise program including exercises on a bike ergometer and gait therapy. The progressive intervention program lasted 12 weeks with three sessions per week, each 40-55 min. CON received the same treatment as IG after the post-tests. Pre- and post-training, VO2max was tested during a graded exercise test using spiroergometry. In addition, ground reaction forces and lower limbs muscle activities were recorded while walking at a constant speed of ∼1 m/s. Results: No statistically significant baseline between group differences was observed for all analyzed variables. Significant group-by-time interactions were found for VO2max (p < 0.001; d = 1.22). The post-hoc test revealed a significant increase in IG (p < 0.001; d = 1.88) but not CON. Significant group-by-time interactions were observed for peak lateral and vertical ground reaction forces during heel contact and peak vertical ground reaction force during push-off (p = 0.001-0.037; d = 0.56-1.53). For IG, post-hoc analyses showed decreases in peak lateral (p < 0.001; d = 1.33) and vertical (p = 0.004; d = 0.55) ground reaction forces during heel contact and increases in peak vertical ground reaction force during push-off (p < 0.001; d = 0.92). In terms of muscle activity, significant group-by-time interactions were found for vastus lateralis and gluteus medius during the loading phase and for vastus medialis during the mid-stance phase, and gastrocnemius medialis during the push-off phase (p = 0.001-0.044; d = 0.54-0.81). Post-hoc tests indicated significant intervention-related increases in vastus lateralis (p = 0.001; d = 1.08) and gluteus medius (p = 0.008; d = 0.67) during the loading phase and vastus medialis activity during mid-stance (p = 0.001; d = 0.86). In addition, post-hoc tests showed decreases in gastrocnemius medialis during the push-off phase in IG only (p < 0.001; d = 1.28). Conclusions: This study demonstrated that an endurance-dominated exercise program has the potential to improve VO2max and diabetes-related abnormal gait in patients with DN. The observed decreases in peak vertical ground reaction force during the heel contact of walking could be due to increased vastus lateralis and gluteus medius activities during the loading phase. Accordingly, we recommend to implement endurance-dominated exercise programs in type 2 diabetic patients because it is feasible, safe and effective by improving aerobic capacity and gait characteristics.}, language = {en} } @misc{KasmiZouhalHammamietal.2021, author = {Kasmi, Sofien and Zouhal, Hassane and Hammami, Raouf and Clark, Cain Craig Truman and Hackney, Anthony C. and Hammami, Amri and Chtara, Moktar and Chortane, Sabri Gaied and Ben Salah, Fatma Zohra and Granacher, Urs and Ben Ounis, Omar}, title = {The Effects of Eccentric and Plyometric Training Programs and Their Combination on Stability and the Functional Performance in the Post-ACL-Surgical Rehabilitation Period of Elite Female Athletes}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-54393}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-543939}, pages = {1 -- 11}, year = {2021}, abstract = {Background: The standard method to treat physically active patients with anterior cruciate ligament (ACL) rupture is ligament reconstruction surgery. The rehabilitation training program is very important to improve functional performance in recreational athletes following ACL reconstruction. Objectives: The aims of this study were to compare the effects of three different training programs, eccentric training (ECC), plyometric training (PLYO), or combined eccentric and plyometric training (COMB), on dynamic balance (Y-BAL), the Lysholm Knee Scale (LKS), the return to sport index (RSI), and the leg symmetry index (LSI) for the single leg hop test for distance in elite female athletes after ACL surgery. Materials and Methods: Fourteen weeks after rehabilitation from surgery, 40 elite female athletes (20.3 ± 3.2 years), who had undergone an ACL reconstruction, participated in a short-term (6 weeks; two times a week) training study. All participants received the same rehabilitation protocol prior to the training study. Athletes were randomly assigned to three experimental groups, ECC (n = 10), PLYO (n = 10), and COMB (n = 10), and to a control group (CON: n = 10). Testing was conducted before and after the 6-week training programs and included the Y-BAL, LKS, and RSI. LSI was assessed after the 6-week training programs only. Results: Adherence rate was 100\% across all groups and no training or test-related injuries were reported. No significant between-group baseline differences (pre-6-week training) were observed for any of the parameters. Significant group-by-time interactions were found for Y-BAL (p < 0.001, ES = 1.73), LKS (p < 0.001, ES = 0.76), and RSI (p < 0.001, ES = 1.39). Contrast analysis demonstrated that COMB yielded significantly greater improvements in Y-BAL, LKS, and RSI (all p < 0.001), in addition to significantly better performances in LSI (all p < 0.001), than CON, PLYO, and ECC, respectively. Conclusion: In conclusion, combined (eccentric/plyometric) training seems to represent the most effective training method as it exerts positive effects on both stability and functional performance in the post-ACL-surgical rehabilitation period of elite female athletes.}, language = {en} } @misc{SariatiZouhalHammamietal.2021, author = {Sariati, Dorsaf and Zouhal, Hassane and Hammami, Raouf and Clark, Cain Craig Truman and Nebigh, Ammar and Chtara, Moktar and Hackney, Anthony C. and Souissi, Nizar and Granacher, Urs and Ben Ounis, Omar}, title = {Association Between Mental Imagery and Change of Direction Performance in Young Elite Soccer Players of Different Maturity Status}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-54465}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-544655}, pages = {1 -- 9}, year = {2021}, abstract = {Previous studies have not considered the potential influence of maturity status on the relationship between mental imagery and change of direction (CoD) speed in youth soccer. Accordingly, this cross-sectional study examined the association between mental imagery and CoD performance in young elite soccer players of different maturity status. Forty young male soccer players, aged 10-17 years, were assigned into two groups according to their predicted age at peak height velocity (PHV) (Pre-PHV; n = 20 and Post-PHV; n = 20). Participants were evaluated on soccer-specific tests of CoD with (CoDBall-15m) and without (CoD-15m) the ball. Participants completed the movement imagery questionnaire (MIQ) with the three- dimensional structure, internal visual imagery (IVI), external visual imagery (EVI), as well as kinesthetic imagery (KI). The Post-PHV players achieved significantly better results than Pre-PHV in EVI (ES = 1.58, large; p < 0.001), CoD-15m (ES = 2.09, very large; p < 0.001) and CoDBall-15m (ES = 1.60, large; p < 0.001). Correlations were significantly different between maturity groups, where, for the pre-PHV group, a negative very large correlation was observed between CoDBall-15m and KI (r = -0.73, p = 0.001). For the post-PHV group, large negative correlations were observed between CoD-15m and IVI (r = -0.55, p = 0.011), EVI (r = -062, p = 0.003), and KI (r = -0.52, p = 0.020). A large negative correlation of CoDBall-15m with EVI (r = -0.55, p = 0.012) and very large correlation with KI (r = -0.79, p = 0.001) were also observed. This study provides evidence of the theoretical and practical use for the CoD tasks stimulus with imagery. We recommend that sport psychology specialists, coaches, and athletes integrated imagery for CoD tasks in pre-pubertal soccer players to further improve CoD related performance.}, language = {en} } @misc{ChaabeneLesinskiBehmetal.2020, author = {Chaabene, Helmi and Lesinski, Melanie and Behm, David George and Granacher, Urs}, title = {Performance- and healthrelated benefits of youth resistance training}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {3}, issn = {1866-8364}, doi = {10.25932/publishup-52691}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-526912}, pages = {12}, year = {2020}, abstract = {There is ample evidence that youth resistance training (RT) is safe, joyful, and effective for different markers of performance (e.g., muscle strength, power, linear sprint speed) and health (e.g., injury prevention). Accordingly, the first aim of this narrative review is to present and discuss the relevance of muscle strength for youth physical development. The second purpose is to report evidence on the effectiveness of RT on muscular fitness (muscle strength, power, muscle endurance), on movement skill performance and injury prevention in youth. There is evidence that RT is effective in enhancing measures of muscle fitness in children and adolescents, irrespective of sex. Additionally, numerous studies indicate that RT has positive effects on fundamental movement skills (e.g., jumping, running, throwing) in youth regardless of age, maturity, training status, and sex. Further, irrespective of age, sex, and training status, regular exposure to RT (e.g., plyometric training) decreases the risk of sustaining injuries in youth. This implies that RT should be a meaningful element of youths' exercise programming. This has been acknowledged by global (e.g., World Health Organization) and national (e.g., National Strength and Conditioning Association) health- and performance-related organizations which is why they recommended to perform RT as an integral part of weekly exercise programs to promote muscular strength, fundamental movement skills, and to resist injuries in youth.}, language = {en} } @misc{GranacherMuehlbauerGoestemeyeretal.2021, author = {Granacher, Urs and Muehlbauer, Thomas and G{\"o}stemeyer, Gerd and Gruber, Stefanie and Gruber, Markus}, title = {The performance of balance exercises during daily tooth brushing is not sufficient to improve balance and muscle strength in healthy older adults}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, issn = {1866-8364}, doi = {10.25932/publishup-52937}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-529379}, pages = {9}, year = {2021}, abstract = {Background High prevalence rates have been reported for physical inactivity, mobility limitations, and falls in older adults. Home-based exercise might be an adequate means to increase physical activity by improving health- (i.e., muscle strength) and skill-related components of physical fitness (i.e., balance), particularly in times of restricted physical activity due to pandemics. Objective The objective of this study was to examine the effects of home-based balance exercises conducted during daily tooth brushing on measures of balance and muscle strength in healthy older adults. Methods Fifty-one older adults were randomly assigned to a balance exercise group (n = 27; age: 65.1 ± 1.1 years) or a passive control group (n = 24; age: 66.2 ± 3.3 years). The intervention group conducted balance exercises over a period of eight weeks twice daily for three minutes each during their daily tooth brushing routine. Pre- and post-intervention, tests were included for the assessment of static steady-state balance (i.e., Romberg test), dynamic steady-state balance (i.e., 10-m single and dual-task walk test using a cognitive and motor interference task), proactive balance (i.e., Timed-Up-and-Go Test [TUG], Functional-Reach-Test [FRT]), and muscle strength (i.e., Chair-Rise-Test [CRT]). Results Irrespective of group, the statistical analysis revealed significant main effects for time (pre vs. post) for dual-task gait speed (p < .001, 1.12 ≤ d ≤ 2.65), TUG (p < .001, d = 1.17), FRT (p = .002, d = 0.92), and CRT (p = .002, d = 0.94) but not for single-task gait speed and for the Romberg-Test. No significant group × time interactions were found for any of the investigated variables. Conclusions The applied lifestyle balance training program conducted twice daily during tooth brushing routines appears not to be sufficient in terms of exercise dosage and difficulty level to enhance balance and muscle strength in healthy adults aged 60-72 years. Consequently, structured balance training programs using higher exercise dosages and/or more difficult balance tasks are recommended for older adults to improve balance and muscle strength.}, language = {en} } @misc{KuemmelBergmannPrieskeetal.2018, author = {K{\"u}mmel, Jakob and Bergmann, Julian and Prieske, Olaf and Kramer, Andreas and Granacher, Urs and Gruber, Markus}, title = {Effects of conditioning hops on drop jump and sprint performance}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {439}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407236}, pages = {8}, year = {2018}, abstract = {Background: It has previously been shown that conditioning activities consisting of repetitive hops have the potential to induce better drop jump (DJ) performance in recreationally active individuals. In the present pilot study, we investigated whether repetitive conditioning hops can also increase reactive jump and sprint performance in sprint-trained elite athletes competing at an international level. Methods: Jump and sprint performances of 5 athletes were randomly assessed under 2 conditions. The control condition (CON) comprised 8 DJs and 4 trials of 30-m sprints. The intervention condition (HOP) consisted of 10 maximal repetitive two-legged hops that were conducted 10 s prior to each single DJ and sprint trial. DJ performance was analyzed using a one-dimensional ground reaction force plate. Step length (SL), contact time (CT), and sprint time (ST) during the 30-m sprints were recorded using an opto-electronic measurement system. Results: Following the conditioning activity, DJ height and external DJ peak power were both significantly increased by 11 \% compared to the control condition. All other variables did not show any significant differences between HOP and CON. Conclusions: In the present pilot study, we were able to demonstrate large improvements in DJ performance even in sprint-trained elite athletes following a conditioning activity consisting of maximal two-legged repetitive hops. This strengthens the hypothesis that plyometric conditioning exercises can induce performance enhancements in elite athletes that are even greater than those observed in recreationally active athletes.. In addition, it appears that the transfer of these effects to other stretch-shortening cycle activities is limited, as we did not observe any changes in sprint performance following the plyometric conditioning activity.}, language = {en} } @misc{RamirezCampilloMoranOliveretal.2022, author = {Ramirez-Campillo, Rodrigo and Moran, Jason and Oliver, Jonathan L. and Pedley, Jason S. and Lloyd, Rhodri S. and Granacher, Urs}, title = {Programming Plyometric-Jump Training in Soccer: A Review}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {813}, issn = {1866-8364}, doi = {10.25932/publishup-58103}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-581031}, pages = {20}, year = {2022}, abstract = {The aim of this review was to describe and summarize the scientific literature on programming parameters related to jump or plyometric training in male and female soccer players of different ages and fitness levels. A literature search was conducted in the electronic databases PubMed, Web of Science and Scopus using keywords related to the main topic of this study (e.g., "ballistic" and "plyometric"). According to the PICOS framework, the population for the review was restricted to soccer players, involved in jump or plyometric training. Among 7556 identified studies, 90 were eligible for inclusion. Only 12 studies were found for females. Most studies (n = 52) were conducted with youth male players. Moreover, only 35 studies determined the effectiveness of a given jump training programming factor. Based on the limited available research, it seems that a dose of 7 weeks (1-2 sessions per week), with ~80 jumps (specific of combined types) per session, using near-maximal or maximal intensity, with adequate recovery between repetitions (<15 s), sets (≥30 s) and sessions (≥24-48 h), using progressive overload and taper strategies, using appropriate surfaces (e.g., grass), and applied in a well-rested state, when combined with other training methods, would increase the outcome of effective and safe plyometric-jump training interventions aimed at improving soccer players physical fitness. In conclusion, jump training is an effective and easy-to-administer training approach for youth, adult, male and female soccer players. However, optimal programming for plyometric-jump training in soccer is yet to be determined in future research.}, language = {en} } @misc{BouamraZouhalRateletal.2022, author = {Bouamra, Marwa and Zouhal, Hassane and Ratel, S{\´e}bastien and Makhlouf, Issam and Bezrati, Ikram and Chtara, Moktar and Behm, David George and Granacher, Urs and Chaouachi, Anis}, title = {Concurrent Training Promotes Greater Gains on Body Composition and Components of Physical Fitness Than Single-Mode Training (Endurance or Resistance) in Youth With Obesity}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-56397}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-563974}, pages = {1 -- 16}, year = {2022}, abstract = {The prevalence of obesity in the pediatric population has become a major public health issue. Indeed, the dramatic increase of this epidemic causes multiple and harmful consequences, Physical activity, particularly physical exercise, remains to be the cornerstone of interventions against childhood obesity. Given the conflicting findings with reference to the relevant literature addressing the effects of exercise on adiposity and physical fitness outcomes in obese children and adolescents, the effect of duration-matched concurrent training (CT) [50\% resistance (RT) and 50\% high-intensity-interval-training (HIIT)] on body composition and physical fitness in obese youth remains to be elucidated. Thus, the purpose of this study was to examine the effects of 9-weeks of CT compared to RT or HIIT alone, on body composition and selected physical fitness components in healthy sedentary obese youth. Out of 73 participants, only 37; [14 males and 23 females; age 13.4 ± 0.9 years; body-mass-index (BMI): 31.2 ± 4.8 kg·m-2] were eligible and randomized into three groups: HIIT (n = 12): 3-4 sets×12 runs at 80-110\% peak velocity, with 10-s passive recovery between bouts; RT (n = 12): 6 exercises; 3-4 sets × 10 repetition maximum (RM) and CT (n = 13): 50\% serial completion of RT and HIIT. CT promoted significant greater gains compared to HIIT and RT on body composition (p < 0.01, d = large), 6-min-walking test distance (6 MWT-distance) and on 6 MWT-VO2max (p < 0.03, d = large). In addition, CT showed substantially greater improvements than HIIT in the medicine ball throw test (20.2 vs. 13.6\%, p < 0.04, d = large). On the other hand, RT exhibited significantly greater gains in relative hand grip strength (p < 0.03, d = large) and CMJ (p < 0.01, d = large) than HIIT and CT. CT promoted greater benefits for fat, body mass loss and cardiorespiratory fitness than HIIT or RT modalities. This study provides important information for practitioners and therapists on the application of effective exercise regimes with obese youth to induce significant and beneficial body composition changes. The applied CT program and the respective programming parameters in terms of exercise intensity and volume can be used by practitioners as an effective exercise treatment to fight the pandemic overweight and obesity in youth.}, language = {en} } @misc{NobariMahmoudzadehKhaliliDencheZamoranoetal.2022, author = {Nobari, Hadi and Mahmoudzadeh Khalili, Sara and Denche Zamorano, Angel Manuel and ‪Bowman, ‪Thomas G. and Granacher, Urs}, title = {Workload is associated with the occurrence of non-contact injuries in professional male soccer players: A pilot study}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-56221}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-562216}, pages = {1 -- 9}, year = {2022}, abstract = {Injuries in professional soccer are a significant concern for teams, and they are caused amongst others by high training load. This cohort study describes the relationship between workload parameters and the occurrence of non-contact injuries, during weeks with high and low workload in professional soccer players throughout the season. Twenty-one professional soccer players aged 28.3 ± 3.9 yrs. who competed in the Iranian Persian Gulf Pro League participated in this 48-week study. The external load was monitored using global positioning system (GPS, GPSPORTS Systems Pty Ltd) and the type of injury was documented daily by the team's medical staff. Odds ratio (OR) and relative risk (RR) were calculated for non-contact injuries for high- and low-load weeks according to acute (AW), chronic (CW), acute to chronic workload ratio (ACWR), and AW variation (Δ-Acute) values. By using Poisson distribution, the interval between previous and new injuries were estimated. Overall, 12 non-contact injuries occurred during high load and 9 during low load weeks. Based on the variables ACWR and Δ-AW, there was a significantly increased risk of sustaining non-contact injuries (p < 0.05) during high-load weeks for ACWR (OR: 4.67), and Δ-AW (OR: 4.07). Finally, the expected time between injuries was significantly shorter in high load weeks for ACWR [1.25 vs. 3.33, rate ratio time (RRT)] and Δ-AW (1.33 vs. 3.45, RRT) respectively, compared to low load weeks. The risk of sustaining injuries was significantly larger during high workload weeks for ACWR, and Δ-AW compared with low workload weeks. The observed high OR in high load weeks indicate that there is a significant relationship between workload and occurrence of non-contact injuries. The predicted time to new injuries is shorter in high load weeks compared to low load weeks. Therefore, the frequency of injuries is higher during high load weeks for ACWR and Δ-AW. ACWR and Δ-AW appear to be good indicators for estimating the injury risk, and the time interval between injuries.}, language = {en} } @misc{GranacherSchellbachKleinetal.2016, author = {Granacher, Urs and Schellbach, J{\"o}rg and Klein, Katja and Prieske, Olaf and Baeyens, Jean-Pierre and M{\"u}hlbauer, Thomas}, title = {Effects of core strength training using stable versus unstable surfaces on physical fitness in adolescents}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93490}, pages = {11}, year = {2016}, abstract = {Background It has been demonstrated that core strength training is an effective means to enhance trunk muscle strength (TMS) and proxies of physical fitness in youth. Of note, cross-sectional studies revealed that the inclusion of unstable elements in core strengthening exercises produced increases in trunk muscle activity and thus provide potential extra training stimuli for performance enhancement. Thus, utilizing unstable surfaces during core strength training may even produce larger performance gains. However, the effects of core strength training using unstable surfaces are unresolved in youth. This randomized controlled study specifically investigated the effects of core strength training performed on stable surfaces (CSTS) compared to unstable surfaces (CSTU) on physical fitness in school-aged children. Methods Twenty-seven (14 girls, 13 boys) healthy subjects (mean age: 14 ± 1 years, age range: 13-15 years) were randomly assigned to a CSTS (n = 13) or a CSTU (n = 14) group. Both training programs lasted 6 weeks (2 sessions/week) and included frontal, dorsal, and lateral core exercises. During CSTU, these exercises were conducted on unstable surfaces (e.g., TOGU© DYNAIR CUSSIONS, THERA-BAND© STABILITY TRAINER). Results Significant main effects of Time (pre vs. post) were observed for the TMS tests (8-22\%, f = 0.47-0.76), the jumping sideways test (4-5\%, f = 1.07), and the Y balance test (2-3\%, f = 0.46-0.49). Trends towards significance were found for the standing long jump test (1-3\%, f = 0.39) and the stand-and-reach test (0-2\%, f = 0.39). We could not detect any significant main effects of Group. Significant Time x Group interactions were detected for the stand-and-reach test in favour of the CSTU group (2\%, f = 0.54). Conclusions Core strength training resulted in significant increases in proxies of physical fitness in adolescents. However, CSTU as compared to CSTS had only limited additional effects (i.e., stand-and-reach test). Consequently, if the goal of training is to enhance physical fitness, then CSTU has limited advantages over CSTS.}, language = {en} } @misc{HortobagyiLesinskiGaebleretal.2015, author = {Hortob{\´a}gyi, Tibor and Lesinski, Melanie and G{\"a}bler, Martijn and VanSwearingen, Jessie M. and Malatesta, Davide and Granacher, Urs}, title = {Effects of three types of exercise interventions on healthy old adults' gait speed}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, issn = {1866-8364}, doi = {10.25932/publishup-43115}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431150}, pages = {17}, year = {2015}, abstract = {Background: Habitual walking speed predicts many clinical conditions later in life, but it declines with age. However, which particular exercise intervention can minimize the age-related gait speed loss is unclear. Purpose: Our objective was to determine the effects of strength, power, coordination, and multimodal exercise training on healthy old adults' habitual and fast gait speed. Methods: We performed a computerized systematic literature search in PubMed and Web of Knowledge from January 1984 up to December 2014. Search terms included 'Resistance training', 'power training', 'coordination training', 'multimodal training', and 'gait speed (outcome term). Inclusion criteria were articles available in full text, publication period over past 30 years, human species, journal articles, clinical trials, randomized controlled trials, English as publication language, and subject age C65 years. The methodological quality of all eligible intervention studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. We computed weighted average standardized mean differences of the intervention-induced adaptations in gait speed using a random-effects model and tested for overall and individual intervention effects relative to no-exercise controls. Results: A total of 42 studies (mean PEDro score of 5.0 +/- 1.2) were included in the analyses (2495 healthy old adults; age 74.2 years [64.4-82.7]; body mass 69.9 +/- 4.9 kg, height 1.64 +/- 0.05 m, body mass index 26.4 +/- 1.9 kg/m(2), and gait speed 1.22 +/- 0.18 m/s). The search identified only one power training study, therefore the subsequent analyses focused only on the effects of resistance, coordination, and multimodal training on gait speed. The three types of intervention improved gait speed in the three experimental groups combined (n = 1297) by 0.10 m/s (+/- 0.12) or 8.4 \% (+/- 9.7), with a large effect size (ES) of 0.84. Resistance (24 studies; n = 613; 0.11 m/s; 9.3 \%; ES: 0.84), coordination (eight studies, n = 198; 0.09 m/s; 7.6 \%; ES: 0.76), and multimodal training (19 studies; n = 486; 0.09 m/s; 8.4 \%, ES: 0.86) increased gait speed statistically and similarly. Conclusions: Commonly used exercise interventions can functionally and clinically increase habitual and fast gait speed and help slow the loss of gait speed or delay its onset.}, language = {en} } @misc{HortobagyiLesinskiFernandez‐del‐Olmoetal.2015, author = {Hortob{\´a}gyi, Tibor and Lesinski, Melanie and Fernandez-del-Olmo, Miguel and Granacher, Urs}, title = {Small and inconsistent effects of whole body vibration on athletic performance}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {627}, issn = {1866-8364}, doi = {10.25932/publishup-43199}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431993}, pages = {23}, year = {2015}, abstract = {Purpose We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. Methods Systematic literature review and meta-analysis. Results Whole body vibration combined with exercise had an overall 0.3 \% acute effect on maximal voluntary leg force (-6.4 \%, effect size = -0.43, 1 study), leg power (4.7 \%, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 \%, effect size = -0.12 to 0.22, 2 studies), and athletic performance (-1.9 \%, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 \% chronic effect on maximal voluntary leg force (14.6 \%, weighted mean effect size = 0.44, 5 studies), leg power (10.7 \%, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 \%, effect size = 0.57 to 0.61, 2 studies), and athletic performance (-1.2 \%, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). Conclusions Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance.}, language = {en} } @misc{GaeblerBerberyanPrieskeetal.2022, author = {G{\"a}bler, Martijn and Berberyan, Hermine S. and Prieske, Olaf and Elferink-Gemser, Marije Titia and Hortobagyi, Tibor and Warnke, Torsten and Granacher, Urs}, title = {Strength Training Intensity and Volume Affect Performance of Young Kayakers/Canoeists}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-54228}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-542283}, pages = {1 -- 10}, year = {2022}, abstract = {Purpose: The aim of this study was to compare the effects of moderate intensity, low volume (MILV) vs. low intensity, high volume (LIHV) strength training on sport-specific performance, measures of muscular fitness, and skeletal muscle mass in young kayakers and canoeists. Methods: Semi-elite young kayakers and canoeists (N = 40, 13 ± 0.8 years, 11 girls) performed either MILV (70-80\% 1-RM, 6-12 repetitions per set) or LIHV (30-40\% 1-RM, 60-120 repetitions per set) strength training for one season. Linear mixed-effects models were used to compare effects of training condition on changes over time in 250 and 2,000 m time trials, handgrip strength, underhand shot throw, average bench pull power over 2 min, and skeletal muscle mass. Both between- and within-subject designs were used for analysis. An alpha of 0.05 was used to determine statistical significance. Results: Between- and within-subject analyses showed that monthly changes were greater in LIHV vs. MILV for the 2,000 m time trial (between: 9.16 s, SE = 2.70, p < 0.01; within: 2,000 m: 13.90 s, SE = 5.02, p = 0.01) and bench pull average power (between: 0.021 W⋅kg-1, SE = 0.008, p = 0.02; within: 0.010 W⋅kg-1, SE = 0.009, p > 0.05). Training conditions did not affect other outcomes. Conclusion: Young sprint kayakers and canoeists benefit from LIHV more than MILV strength training in terms of 2,000 m performance and muscular endurance (i.e., 2 min bench pull power).}, language = {en} } @misc{PrieskeMaffiulettiGranacher2018, author = {Prieske, Olaf and Maffiuletti, Nicola A. and Granacher, Urs}, title = {Postactivation Potentiation of the Plantar Flexors Does Not Directly Translate to Jump Performance in Female Elite Young Soccer Players}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {483}, issn = {1866-8364}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420558}, pages = {10}, year = {2018}, abstract = {Background: Infection with human immunodeficiency virus (HIV) affects muscle mass, altering independent activities of people living with HIV (PLWH). Resistance training alone (RT) or combined with aerobic exercise (AE) is linked to improved muscle mass and strength maintenance in PLWH. These exercise benefits have been the focus of different meta-analyses, although only a limited number of studies have been identified up to the year 2013/4. An up-to-date systematic review and meta-analysis concerning the effect of RT alone or combined with AE on strength parameters and hormones is of high value, since more and recent studies dealing with these types of exercise in PLWH have been published. Methods: Randomized controlled trials evaluating the effects of RT alone, AE alone or the combination of both (AERT) on PLWH was performed through five web-databases up to December 2017. Risk of bias and study quality was attained using the PEDro scale. Weighted mean difference (WMD) from baseline to post-intervention changes was calculated. The I2 statistics for heterogeneity was calculated. Results: Thirteen studies reported strength outcomes. Eight studies presented a low risk of bias. The overall change in upper body strength was 19.3 Kg (95\% CI: 9.8±28.8, p< 0.001) after AERT and 17.5 Kg (95\% CI: 16±19.1, p< 0.001) for RT. Lower body change was 29.4 Kg (95\% CI: 18.1±40.8, p< 0.001) after RT and 10.2 Kg (95\% CI: 6.7±13.8, p< 0.001) for AERT. Changes were higher after controlling for the risk of bias in upper and lower body strength and for supervised exercise in lower body strength. A significant change towards lower levels of IL-6 was found (-2.4 ng/dl (95\% CI: -2.6, -2.1, p< 0.001). Conclusion: Both resistance training alone and combined with aerobic exercise showed a positive change when studies with low risk of bias and professional supervision were analyzed, improving upper and, more critically, lower body muscle strength. Also, this study found that exercise had a lowering effect on IL-6 levels in PLWH.}, language = {en} } @misc{GschwindBridenbaughReinhardetal.2017, author = {Gschwind, Yves J. and Bridenbaugh, Stephanie A. and Reinhard, Sarah and Granacher, Urs and Monsch, Andreas U. and Kressig, Reto W.}, title = {Ginkgo biloba special extract LI 1370 improves dual-task walking in patients with MCI}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {870}, issn = {1866-8372}, doi = {10.25932/publishup-43479}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-434796}, pages = {609 -- 619}, year = {2017}, abstract = {Background In patients with mild cognitive impairment (MCI), gait instability, particularly in dual-task situations, has been associated with impaired executive function and an increased fall risk. Ginkgo biloba extract (GBE) could be an effective mean to improve gait stability. Aims This study investigated the effect of GBE on spatiotemporal gait parameters of MCI patients while walking under single and dual-task conditions. Methods Fifty patients aged 50-85 years with MCI and associated dual-task-related gait impairment participated in this randomised, double-blind, placebo-controlled, exploratory phase IV drug trial. Intervention group (IG) patients received GBE (Symfona (R) forte 120 mg) twice-daily for 6 months while control group (CG) patients received placebo capsules. A 6-month open-label phase with identical GBE dosage followed. Gait was quantified at months 0, 3, 6 and 12. Results After 6 months, dual-task-related cadence increased in the IG compared to the CG (p = 0.019, d = 0.71). No significant changes, but GBE-associated numerical non-significant trends were found after 6-month treatment for dual-task-related gait velocity and stride time variability. Discussion Findings suggest that 120 mg of GBE twice-daily for at least 6 months may improve dual-task-related gait performance in patients with MCI. Conclusions The observed gait improvements add to the understanding of the self-reported unspecified improvements among MCI patients when treated with standardised GBE.}, language = {en} } @misc{ZinkeWarnkeGaebleretal.2019, author = {Zinke, Fridolin and Warnke, Torsten and G{\"a}bler, Martijn and Granacher, Urs}, title = {Effects of Isokinetic Training on Trunk Muscle Fitness and Body Composition in World-Class Canoe Sprinters}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {536}, issn = {1866-8364}, doi = {10.25932/publishup-42489}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424898}, year = {2019}, abstract = {In canoe sprint, the trunk muscles play an important role in stabilizing the body in an unstable environment (boat) and in generating forces that are transmitted through the shoulders and arms to the paddle for propulsion of the boat. Isokinetic training is well suited for sports in which propulsion is generated through water resistance due to similarities in the resistive mode. Thus, the purpose of this study was to determine the effects of isokinetic training in addition to regular sport-specific training on trunk muscular fitness and body composition in world-class canoeists and to evaluate associations between trunk muscular fitness and canoe-specific performance. Nine world-class canoeists (age: 25.6 ± 3.3 years; three females; four world champions; three Olympic gold medalists) participated in an 8-week progressive isokinetic training with a 6-week block "muscle hypertrophy" and a 2-week block "muscle power." Pre- and post-tests included the assessment of peak isokinetic torque at different velocities in concentric (30 and 140∘s-1) and eccentric (30 and 90∘s-1) mode, trunk muscle endurance, and body composition (e.g., body fat, segmental lean mass). Additionally, peak paddle force was assessed in the flume at a water current of 3.4 m/s. Significant pre-to-post increases were found for peak torque of the trunk rotators at 30∘s-1 (p = 0.047; d = 0.4) and 140∘s-1 (p = 0.014; d = 0.7) in concentric mode. No significant pre-to-post changes were detected for eccentric trunk rotator torque, trunk muscle endurance, and body composition (p > 0.148). Significant medium-to-large correlations were observed between concentric trunk rotator torque but not trunk muscle endurance and peak paddle force, irrespective of the isokinetic movement velocity (all r ≥ 0.886; p ≤ 0.008). Isokinetic trunk rotator training is effective in improving concentric trunk rotator strength in world-class canoe sprinters. It is recommended to progressively increase angular velocity from 30∘s-1 to 140∘s-1 over the course of the training period.}, language = {en} } @misc{PeitzBehringerGranacher2019, author = {Peitz, Matti and Behringer, Michael and Granacher, Urs}, title = {A systematic review on the effects of resistance and plyometric training on physical fitness in youth}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {498}, issn = {1866-8364}, doi = {10.25932/publishup-42220}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422201}, year = {2019}, abstract = {Introduction To date, several meta-analyses clearly demonstrated that resistance and plyometric training are effective to improve physical fitness in children and adolescents. However, a methodological limitation of meta-analyses is that they synthesize results from different studies and hence ignore important differences across studies (i.e., mixing apples and oranges). Therefore, we aimed at examining comparative intervention studies that assessed the effects of age, sex, maturation, and resistance or plyometric training descriptors (e.g., training intensity, volume etc.) on measures of physical fitness while holding other variables constant. Methods To identify relevant studies, we systematically searched multiple electronic databases (e.g., PubMed) from inception to March 2018. We included resistance and plyometric training studies in healthy young athletes and non-athletes aged 6 to 18 years that investigated the effects of moderator variables (e.g., age, maturity, sex, etc.) on components of physical fitness (i.e., muscle strength and power). Results Our systematic literature search revealed a total of 75 eligible resistance and plyometric training studies, including 5,138 participants. Mean duration of resistance and plyometric training programs amounted to 8.9 ± 3.6 weeks and 7.1±1.4 weeks, respectively. Our findings showed that maturation affects plyometric and resistance training outcomes differently, with the former eliciting greater adaptations pre-peak height velocity (PHV) and the latter around- and post-PHV. Sex has no major impact on resistance training related outcomes (e.g., maximal strength, 10 repetition maximum). In terms of plyometric training, around-PHV boys appear to respond with larger performance improvements (e.g., jump height, jump distance) compared with girls. Different types of resistance training (e.g., body weight, free weights) are effective in improving measures of muscle strength (e.g., maximum voluntary contraction) in untrained children and adolescents. Effects of plyometric training in untrained youth primarily follow the principle of training specificity. Despite the fact that only 6 out of 75 comparative studies investigated resistance or plyometric training in trained individuals, positive effects were reported in all 6 studies (e.g., maximum strength and vertical jump height, respectively). Conclusions The present review article identified research gaps (e.g., training descriptors, modern alternative training modalities) that should be addressed in future comparative studies.}, language = {en} } @misc{JafarnezhadgeroFatollahiAmirzadehetal.2019, author = {Jafarnezhadgero, Amir Ali and Fatollahi, Amir and Amirzadeh, Nasrin and Siahkouhian, Marefat and Granacher, Urs}, title = {Ground Reaction Forces and Muscle Activity While Walking on Sand versus Stable Ground in Individuals with Pronated Feet Compared with Healthy Controls}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {590}, issn = {1866-8364}, doi = {10.25932/publishup-44102}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-441027}, pages = {17}, year = {2019}, abstract = {Background Sand is an easy-to-access, cost-free resource that can be used to treat pronated feet (PF). Therefore, the aims of this study were to contrast the effects of walking on stable ground versus walking on sand on ground reaction forces (GRFs) and electromyographic (EMG) activity of selected lower limb muscles in PF individuals compared with healthy controls. Methods Twenty-nine controls aged 22.2±2.5 years and 30 PF individuals aged 22.2±1.9 years were enrolled in this study. Participants walked at preferred speed and in randomized order over level ground and sand. A force plate was included in the walkway to collect GRFs. Muscle activities were recorded using EMG system. Results No statistically significant between-group differences were found in preferred walking speed when walking on stable ground (PF: 1.33±0.12 m/s; controls: 1.35±0.14 m/s; p = 0.575; d = 0.15) and sand (PF: 1.19±0.11 m/s; controls: 1.23±0.18 m/s; p = 0.416; d = 0.27). Irrespective of the group, walking on sand (1.21±0.15 m/s) resulted in significantly lower gait speed compared with stable ground walking (1.34±0.13 m/s) (p<0.001; d = 0.93). Significant main effects of "surface" were found for peak posterior GRFs at heel contact, time to peak for peak lateral GRFs at heel contact, and peak anterior GRFs during push-off (p<0.044; d = 0.27-0.94). Pair-wise comparisons revealed significantly smaller peak posterior GRFs at heel contact (p = 0.005; d = 1.17), smaller peak anterior GRFs during push-off (p = 0.001; d = 1.14), and time to peak for peak lateral GRFs (p = 0.044; d = 0.28) when walking on sand. No significant main effects of "group" were observed for peak GRFs and their time to peak (p>0.05; d = 0.06-1.60). We could not find any significant group by surface interactions for peak GRFs and their time to peak. Significant main effects of "surface" were detected for anterior-posterior impulse and peak positive free moment amplitude (p<0.048; d = 0.54-0.71). Pair-wise comparisons revealed a significantly larger peak positive free moment amplitude (p = 0.010; d = 0.71) and a lower anterior-posterior impulse (p = 0.048; d = 0.38) when walking on sand. We observed significant main effects of "group" for the variable loading rate (p<0.030; d = 0.59). Pair-wise comparisons revealed significantly lower loading rates in PF compared with controls (p = 0.030; d = 0.61). Significant group by surface interactions were observed for the parameter peak positive free moment amplitude (p<0.030; d = 0.59). PF individuals exhibited a significantly lower peak positive free moment amplitude (p = 0.030, d = 0.41) when walking on sand. With regards to EMG, no significant main effects of "surface", main effects of "group", and group by surface interactions were observed for the recorded muscles during the loading and push-off phases (p>0.05; d = 0.00-0.53). Conclusions The observed lower velocities during walking on sand compared with stable ground were accompanied by lower peak positive free moments during the push-off phase and loading rates during the loading phase. Our findings of similar lower limb muscle activities during walking on sand compared with stable ground in PF together with lower free moment amplitudes, vertical loading rates, and lower walking velocities on sand may indicate more relative muscle activity on sand compared with stable ground. This needs to be verified in future studies.}, language = {en} } @misc{JafarnezhadgeroMadadiShadAlaviMehretal.2018, author = {Jafarnezhadgero, Amir Ali and Madadi-Shad, Morteza and Alavi-Mehr, Seyed Majid and Granacher, Urs}, title = {The long-term use of foot orthoses affects walking kinematics and kinetics of children with flexible flat feet}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {479}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419852}, pages = {19}, year = {2018}, abstract = {Background Due to inconclusive evidence on the effects of foot orthoses treatment on lower limb kinematics and kinetics in children, studies are needed that particularly evaluate the long-term use of foot orthoses on lower limb alignment during walking. Thus, the main objective of this study was to evaluate the effects of long-term treatment with arch support foot orthoses versus a sham condition on lower extremity kinematics and kinetics during walking in children with flexible flat feet. Methods Thirty boys aged 8-12 years with flexible flat feet participated in this study. While the experimental group (n = 15) used medial arch support foot orthoses during everyday activities over a period of four months, the control group (n = 15) received flat 2-mm-thick insoles (i.e., sham condition) for the same time period. Before and after the intervention period, walking kinematics and ground reaction forces were collected. Results Significant group by time interactions were observed during walking at preferred gait speed for maximum ankle eversion, maximum ankle internal rotation angle, minimum knee abduction angle, maximum knee abduction angle, maximum knee external rotation angle, maximum knee internal rotation angle, maximum hip extension angle, and maximum hip external rotation angle in favor of the foot orthoses group. In addition, statistically significant group by time interactions were detected for maximum posterior, and vertical ground reaction forces in favor of the foot orthoses group. Conclusions The long-term use of arch support foot orthoses proved to be feasible and effective in boys with flexible flat feet to improve lower limb alignment during walking.}, language = {en} } @misc{GebelBuschStelzeletal.2022, author = {Gebel, Arnd and Busch, Aglaja and Stelzel, Christine and Hortob{\´a}gyi, Tibor and Granacher, Urs}, title = {Effects of Physical and Mental Fatigue on Postural Sway and Cortical Activity in Healthy Young Adults}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-56441}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-564419}, pages = {1 -- 14}, year = {2022}, abstract = {Physical fatigue (PF) negatively affects postural control, resulting in impaired balance performance in young and older adults. Similar effects on postural control can be observed for mental fatigue (MF) mainly in older adults. Controversial results exist for young adults. There is a void in the literature on the effects of fatigue on balance and cortical activity. Therefore, this study aimed to examine the acute effects of PF and MF on postural sway and cortical activity. Fifteen healthy young adults aged 28 ± 3 years participated in this study. MF and PF protocols comprising of an all-out repeated sit-to-stand task and a computer-based attention network test, respectively, were applied in random order. Pre and post fatigue, cortical activity and postural sway (i.e., center of pressure displacements [CoPd], velocity [CoPv], and CoP variability [CV CoPd, CV CoPv]) were tested during a challenging bipedal balance board task. Absolute spectral power was calculated for theta (4-7.5 Hz), alpha-2 (10.5-12.5 Hz), beta-1 (13-18 Hz), and beta-2 (18.5-25 Hz) in frontal, central, and parietal regions of interest (ROI) and baseline-normalized. Inference statistics revealed a significant time-by-fatigue interaction for CoPd (p = 0.009, d = 0.39, Δ 9.2\%) and CoPv (p = 0.009, d = 0.36, Δ 9.2\%), and a significant main effect of time for CoP variability (CV CoPd: p = 0.001, d = 0.84; CV CoPv: p = 0.05, d = 0.62). Post hoc analyses showed a significant increase in CoPd (p = 0.002, d = 1.03) and CoPv (p = 0.003, d = 1.03) following PF but not MF. For cortical activity, a significant time-by-fatigue interaction was found for relative alpha-2 power in parietal (p < 0.001, d = 0.06) areas. Post hoc tests indicated larger alpha-2 power increases after PF (p < 0.001, d = 1.69, Δ 3.9\%) compared to MF (p = 0.001, d = 1.03, Δ 2.5\%). In addition, changes in parietal alpha-2 power and measures of postural sway did not correlate significantly, irrespective of the applied fatigue protocol. No significant changes were found for the other frequency bands, irrespective of the fatigue protocol and ROI under investigation. Thus, the applied PF protocol resulted in increased postural sway (CoPd and CoPv) and CoP variability accompanied by enhanced alpha-2 power in the parietal ROI while MF led to increased CoP variability and alpha-2 power in our sample of young adults. Potential underlying cortical mechanisms responsible for the greater increase in parietal alpha-2 power after PF were discussed but could not be clearly identified as cause. Therefore, further future research is needed to decipher alternative interpretations.}, language = {en} } @misc{LesinskiMuehlbauerGranacher2017, author = {Lesinski, Melanie and M{\"u}hlbauer, Thomas and Granacher, Urs}, title = {Concurrent validity of the Gyko inertial sensor system for the assessment of vertical jump height in female sub-elite youth soccer players}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-400967}, pages = {9}, year = {2017}, abstract = {Background: The aim of the present study was to verify concurrent validity of the Gyko inertial sensor system for the assessment of vertical jump height. - Methods: Nineteen female sub-elite youth soccer players (mean age: 14.7 ± 0.6 years) performed three trials of countermovement (CMJ) and squat jumps (SJ), respectively. Maximal vertical jump height was simultaneously quantified with the Gyko system, a Kistler force-plate (i.e., gold standard), and another criterion device that is frequently used in the field, the Optojump system. - Results: Compared to the force-plate, the Gyko system determined significant systematic bias for mean CMJ (-0.66 cm, p < 0.01, d = 1.41) and mean SJ (-0.91 cm, p < 0.01, d = 1.69) height. Random bias was ± 3.2 cm for CMJ and ± 4.0 cm for SJ height and intraclass correlation coefficients (ICCs) were "excellent" (ICC = 0.87 for CMJ and 0.81 for SJ). Compared to the Optojump device, the Gyko system detected a significant systematic bias for mean CMJ (0.55 cm, p < 0.05, d = 0.94) but not for mean SJ (0.39 cm) height. Random bias was ± 3.3 cm for CMJ and ± 4.2 cm for SJ height and ICC values were "excellent" (ICC = 0.86 for CMJ and 0.82 for SJ). - Conclusion: Consequently, apparatus specific regression equations were provided to estimate true vertical jump height for the Kistler force-plate and the Optojump device from Gyko-derived data. Our findings indicate that the Gyko system cannot be used interchangeably with a Kistler force-plate and the Optojump device in trained individuals. It is suggested that practitioners apply the correction equations to estimate vertical jump height for the force-plate and the Optojump system from Gyko-derived data.}, language = {en} } @misc{KibeleClassenMuehlbaueretal.2014, author = {Kibele, Armin and Classen, Claudia and M{\"u}hlbauer, Thomas and Granacher, Urs and Behm, David George}, title = {Metastability in plyometric training on unstable surfaces}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {606}, issn = {1866-8364}, doi = {10.25932/publishup-42901}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429013}, pages = {13}, year = {2014}, abstract = {Background In the past, plyometric training (PT) has been predominantly performed on stable surfaces. The purpose of this pilot study was to examine effects of a 7-week lower body PT on stable vs. unstable surfaces. This type of exercise condition may be denoted as metastable equilibrium. Methods Thirty-three physically active male sport science students (age: 24.1 ± 3.8 years) were randomly assigned to a PT group (n = 13) exercising on stable (STAB) and a PT group (n = 20) on unstable surfaces (INST). Both groups trained countermovement jumps, drop jumps, and practiced a hurdle jump course. In addition, high bar squats were performed. Physical fitness tests on stable surfaces (hexagonal obstacle test, countermovement jump, hurdle drop jump, left-right hop, dynamic and static balance tests, and leg extension strength) were used to examine the training effects. Results Significant main effects of time (ANOVA) were found for the countermovement jump, hurdle drop jump, hexagonal test, dynamic balance, and leg extension strength. A significant interaction of time and training mode was detected for the countermovement jump in favor of the INST group. No significant improvements were evident for either group in the left-right hop and in the static balance test. Conclusions These results show that lower body PT on unstable surfaces is a safe and efficient way to improve physical performance on stable surfaces.}, language = {en} } @misc{WickLeegerAschmannMonnetal.2017, author = {Wick, Kristin and Leeger-Aschmann, Claudia S. and Monn, Nico D. and Radtke, Thomas and Ott, Laura V. and Rebholz, Cornelia E. and Cruz, Sergio and Gerber, Natalie and Schmutz, Einat A. and Puder, Jardena J. and Munsch, Simone and Kakebeeke, Tanja H. and Jenni, Oskar G. and Granacher, Urs and Kriemler, Susi}, title = {Interventions to promote fundamental movement skills in childcare and kindergarten}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {702}, issn = {1866-8364}, doi = {10.25932/publishup-43546}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435463}, pages = {26}, year = {2017}, abstract = {Background Proficiency in fundamental movement skills (FMS) lays the foundation for being physically active and developing more complex motor skills. Improving these motor skills may provide enhanced opportunities for the development of a variety of perceptual, social, and cognitive skills. Objective The objective of this systematic review and meta-analysis was to assess the effects of FMS interventions on actual FMS, targeting typically developing young children. Method Searches in seven databases (CINAHL, Embase, MEDLINE, PsycINFO, PubMed, Scopus, Web of Science) up to August 2015 were completed. Trials with children (aged 2-6 years) in childcare or kindergarten settings that applied FMS-enhancing intervention programs of at least 4 weeks and meeting the inclusion criteria were included. Standardized data extraction forms were used. Risk of bias was assessed using a standard scoring scheme (Effective Public Health Practice Project-Quality Assessment Tool for Quantitative Studies [EPHPP]). We calculated effects on overall FMS, object control and locomotor subscales (OCS and LMS) by weighted standardized mean differences (SMDbetween) using random-effects models. Certainty in training effects was evaluated using GRADE (Grading of Recommendations Assessment, Development, and Evaluation System). Results Thirty trials (15 randomized controlled trials and 15 controlled trials) involving 6126 preschoolers (aged 3.3-5.5 years) revealed significant differences among groups in favor of the intervention group (INT) with small-to-large effects on overall FMS (SMDbetween 0.46), OCS (SMDbetween 1.36), and LMS (SMDbetween 0.94). Our certainty in the treatment estimates based on GRADE is very low. Conclusions Although there is relevant effectiveness of programs to improve FMS proficiency in healthy young children, they need to be interpreted with care as they are based on low-quality evidence and immediate post-intervention effects without long-term follow-up.}, language = {en} } @misc{BeurskensMuehlbauerGranacher2015, author = {Beurskens, Rainer and M{\"u}hlbauer, Thomas and Granacher, Urs}, title = {Association of dual-task walking performance and leg muscle quality in healthy children}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-75100}, pages = {7}, year = {2015}, abstract = {Background Previous literature mainly introduced cognitive functions to explain performance decrements in dual-task walking, i.e., changes in dual-task locomotion are attributed to limited cognitive information processing capacities. In this study, we enlarge existing literature and investigate whether leg muscular capacity plays an additional role in children's dual-task walking performance. Methods To this end, we had prepubescent children (mean age: 8.7 ± 0.5 years, age range: 7-9 years) walk in single task (ST) and while concurrently conducting an arithmetic subtraction task (DT). Additionally, leg lean tissue mass was assessed. Results Findings show that both, boys and girls, significantly decrease their gait velocity (f = 0.73), stride length (f = 0.62) and cadence (f = 0.68) and increase the variability thereof (f = 0.20-0.63) during DT compared to ST. Furthermore, stepwise regressions indicate that leg lean tissue mass is closely associated with step time and the variability thereof during DT (R2 = 0.44, p = 0.009). These associations between gait measures and leg lean tissue mass could not be observed for ST (R2 = 0.17, p = 0.19). Conclusion We were able to show a potential link between leg muscular capacities and DT walking performance in children. We interpret these findings as evidence that higher leg muscle mass in children may mitigate the impact of a cognitive interference task on DT walking performance by inducing enhanced gait stability.}, language = {en} } @misc{NevillNegraMyersetal.2021, author = {Nevill, Alan M. and Negra, Yassine and Myers, Tony D. and Duncan, Michael J. and Chaabene, Helmi and Granacher, Urs}, title = {Are Early or Late Maturers Likely to Be Fitter in the General Population?}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {695}, issn = {1866-8364}, doi = {10.25932/publishup-48992}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-489928}, pages = {18}, year = {2021}, abstract = {The present study aims to identify the optimal body-size/shape and maturity characteristics associated with superior fitness test performances having controlled for body-size, sex, and chronological-age differences. The sample consisted of 597 Tunisian children (396 boys and 201 girls) aged 8 to 15 years. Three sprint speeds recorded at 10, 20 and 30 m; two vertical and two horizontal jump tests; a change-of-direction and a handgrip-strength tests, were assessed during physical-education classes. Allometric modelling was used to identify the benefit of being an early or late maturer. Findings showed that being tall and light is the ideal shape to be successful at most physical fitness tests, but the height-to-weight "shape" ratio seems to be test-dependent. Having controlled for body-size/shape, sex, and chronological age, the model identified maturity-offset as an additional predictor. Boys who go earlier/younger through peak-height-velocity (PHV) outperform those who go at a later/older age. However, most of the girls' physical-fitness tests peaked at the age at PHV and decline thereafter. Girls whose age at PHV was near the middle of the age range would appear to have an advantage compared to early or late maturers. These findings have important implications for talent scouts and coaches wishing to recruit children into their sports/athletic clubs.}, language = {en} } @misc{GolleMuehlbauerWicketal.2015, author = {Golle, Kathleen and M{\"u}hlbauer, Thomas and Wick, Ditmar and Granacher, Urs}, title = {Physical Fitness Percentiles of German Children Aged 9-12 Years}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-86613}, year = {2015}, abstract = {Background Generating percentile values is helpful for the identification of children with specific fitness characteristics (i.e., low or high fitness level) to set appropriate fitness goals (i.e., fitness/health promotion and/or long-term youth athlete development). Thus, the aim of this longitudinal study was to assess physical fitness development in healthy children aged 9-12 years and to compute sex- and age-specific percentile values. Methods Two-hundred and forty children (88 girls, 152 boys) participated in this study and were tested for their physical fitness. Physical fitness was assessed using the 50-m sprint test (i.e., speed), the 1-kg ball push test, the triple hop test (i.e., upper- and lower- extremity muscular power), the stand-and-reach test (i.e., flexibility), the star run test (i.e., agility), and the 9-min run test (i.e., endurance). Age- and sex-specific percentile values (i.e., P10 to P90) were generated using the Lambda, Mu, and Sigma method. Adjusted (for change in body weight, height, and baseline performance) age- and sex-differences as well as the interactions thereof were expressed by calculating effect sizes (Cohen's d). Results Significant main effects of Age were detected for all physical fitness tests (d = 0.40-1.34), whereas significant main effects of Sex were found for upper-extremity muscular power (d = 0.55), flexibility (d = 0.81), agility (d = 0.44), and endurance (d = 0.32) only. Further, significant Sex by Age interactions were observed for upper-extremity muscular power (d = 0.36), flexibility (d = 0.61), and agility (d = 0.27) in favor of girls. Both, linear and curvilinear shaped curves were found for percentile values across the fitness tests. Accelerated (curvilinear) improvements were observed for upper-extremity muscular power (boys: 10-11 yrs; girls: 9-11 yrs), agility (boys: 9-10 yrs; girls: 9-11 yrs), and endurance (boys: 9-10 yrs; girls: 9-10 yrs). Tabulated percentiles for the 9-min run test indicated that running distances between 1,407-1,507 m, 1,479-1,597 m, 1,423-1,654 m, and 1,433-1,666 m in 9- to 12-year-old boys and 1,262-1,362 m, 1,329-1,434 m, 1,392-1,501 m, and 1,415-1,526 m in 9- to 12-year-old girls correspond to a "medium" fitness level (i.e., P40 to P60) in this population. Conclusions The observed differences in physical fitness development between boys and girls illustrate that age- and sex-specific maturational processes might have an impact on the fitness status of healthy children. Our statistical analyses revealed linear (e.g., lower-extremity muscular power) and curvilinear (e.g., agility) models of fitness improvement with age which is indicative of timed and capacity-specific fitness development pattern during childhood. Lastly, the provided age- and sex-specific percentile values can be used by coaches for talent identification and by teachers for rating/grading of children's motor performance.}, language = {en} } @misc{GranacherKissLueder2018, author = {Granacher, Urs and Kiss, Rainer and L{\"u}der, Benjamin}, title = {Single- and Dual-Task Balance Training Are Equally Effective in Youth}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {432}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-411679}, pages = {12}, year = {2018}, abstract = {Due to maturation of the postural control system and secular declines in motor performance, adolescents experience deficits in postural control during standing and walking while concurrently performing cognitive interference tasks. Thus, adequately designed balance training programs may help to counteract these deficits. While the general effectiveness of youth balance training is well-documented, there is hardly any information available on the specific effects of single-task (ST) versus dual-task (DT) balance training. Therefore, the objectives of this study were (i) to examine static/dynamic balance performance under ST and DT conditions in adolescents and (ii) to study the effects of ST versus DT balance training on static/dynamic balance under ST and DT conditions in adolescents. Twenty-eight healthy girls and boys aged 12-13 years were randomly assigned to either 8 weeks of ST or DT balance training. Before and after training, postural sway and spatio-temporal gait parameters were registered under ST (standing/walking only) and DT conditions (standing/walking while concurrently performing an arithmetic task). At baseline, significantly slower gait speed (p < 0.001, d = 5.1), shorter stride length (p < 0.001, d = 4.8), and longer stride time (p < 0.001, d = 3.8) were found for DT compared to ST walking but not standing. Training resulted in significant pre-post decreases in DT costs for gait velocity (p < 0.001, d = 3.1), stride length (-45\%, p < 0.001, d = 2.4), and stride time (-44\%, p < 0.01, d = 1.9). Training did not induce any significant changes (p > 0.05, d = 0-0.1) in DT costs for all parameters of secondary task performance during standing and walking. Training produced significant pre-post increases (p = 0.001; d = 1.47) in secondary task performance while sitting. The observed increase was significantly greater for the ST training group (p = 0.04; d = 0.81). For standing, no significant changes were found over time irrespective of the experimental group. We conclude that adolescents showed impaired DT compared to ST walking but not standing. ST and DT balance training resulted in significant and similar changes in DT costs during walking. Thus, there appears to be no preference for either ST or DT balance training in adolescents.}, language = {en} } @misc{SariatiHammamiZouhaletal., author = {Sariati, Dorsaf and Hammami, Raouf and Zouhal, Hassane and Clark, Cain Craig Truman and Nebigh, Ammar and Chtara, Moktar and Chortane, Sabri Gaied and Hackney, Anthony C. and Souissi, Nizar and Granacher, Urs and Ben Ounis, Omar}, title = {Improvement of Physical Performance Following a 6 Week Change-of-Direction Training Program in Elite Youth Soccer Players of Different Maturity Levels}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}t Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-54101}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-541019}, pages = {1 -- 8}, abstract = {Background: Change-of-direction (CoD) is a necessary physical ability of a field sport and may vary in youth players according to their maturation status. Objectives: The aim of this study is: to compare the effectiveness of a 6-week CoD training intervention on dynamic balance (CS-YBT), horizontal jump (5JT), speed (10 and 30-m linear sprint times), CoD with (15 m-CoD + B) and without (15 m-CoD) the ball, in youth male soccer players at different levels of maturity [pre- and post-peak height velocity (PHV)]. Materials and Methods: Thirty elite male youth soccer players aged 10-17 years from the Tunisian first division participated in this study. The players were divided into pre- (G1, n = 15) and post-PHV (G2, n = 15) groups. Both groups completed a similar 6-week training program with two sessions per week of four CoD exercises. All players completed the following tests before and after intervention: CS-YBT; 5 JT; 10, 30, and 15 m-CoD; and 15 m-CoD + B, and data were analyzed using ANCOVA. Results: All 30 players completed the study according to the study design and methodology. Adherence rate was 100\% across all groups, and no training or test-related injuries were reported. Pre-PHV and post-PHV groups showed significant amelioration post-intervention for all dependent variables (after test > before test; p < 0.01, d = 0.09-1.51). ANOVA revealed a significant group × time interaction only for CS-YBT (F = 4.45; p < 0.04; η2 = 0.14), 5JT (F = 6.39; p < 0.02; η2 = 0.18), and 15 m-CoD (F = 7.88; p < 0.01; η2 = 0.22). CS-YBT, 5JT, and 15 m-CoD improved significantly in the post-PHV group (+ 4.56\%, effect size = 1.51; + 4.51\%, effect size = 1.05; and -3.08\%, effect size = 0.51, respectively), more than the pre-PHV group (+ 2.77\%, effect size = 0.85; + 2.91\%, effect size = 0.54; and -1.56\%, effect size = 0.20, respectively). Conclusion: The CoD training program improved balance, horizontal jump, and CoD without the ball in male preadolescent and adolescent soccer players, and this improvement was greater in the post-PHV players. The maturity status of the athletes should be considered when programming CoD training for soccer players.}, language = {en} } @misc{ElAshkerChaabeneNegraetal.2018, author = {El-Ashker, Said and Chaabene, Helmi and Negra, Yassine and Prieske, Olaf and Granacher, Urs}, title = {Cardio-Respiratory endurance responses following a simulated 3 x 3 minutes amateur boxing contest in elite level boxers}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {675}, issn = {1866-8364}, doi = {10.25932/publishup-47233}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472338}, pages = {10}, year = {2018}, abstract = {This study aimed at examining physiological responses (i.e., oxygen uptake [VO2] and heart rate [HR]) to a semi-contact 3 x 3-min format, amateur boxing combat simulation in elite level male boxers. Eleven boxers aged 21.4 +/- 2.1 years (body height 173.4 +/- 3.7, body mass 74.9 +/- 8.6 kg, body fat 12.1 +/- 1.9, training experience 5.7 +/- 1.3 years) volunteered to participate in this study. They performed a maximal graded aerobic test on a motor-driven treadmill to determine maximum oxygen uptake (VO2max), oxygen uptake (VO2AT) and heart rate (HRAT) at the anaerobic threshold, and maximal heart rate (HRmax). Additionally, VO2 and peak HR (HRpeak) were recorded following each boxing round. Results showed no significant differences between VO2max values derived from the treadmill running test and VO2 outcomes of the simulated boxing contest (p > 0.05, d = 0.02 to 0.39). However, HRmax and HRpeak recorded from the treadmill running test and the simulated amateur boxing contest, respectively, displayed significant differences regardless of the boxing round (p < 0.01, d = 1.60 to 3.00). In terms of VO2 outcomes during the simulated contest, no significant between-round differences were observed (p = 0.19, d = 0.17 to 0.73). Irrespective of the boxing round, the recorded VO2 was >90\% of the VO2max. Likewise, HRpeak observed across the three boxing rounds were >= 90\% of the HRmax. In summary, the simulated 3 x 3-min amateur boxing contest is highly demanding from a physiological standpoint. Thus, coaches are advised to systematically monitor internal training load for instance through rating of perceived exertion to optimize training-related adaptations and to prevent boxers from overreaching and/or overtraining.}, language = {en} } @misc{GranacherLacroixMuehlbaueretal.2017, author = {Granacher, Urs and Lacroix, Andre and M{\"u}hlbauer, Thomas and Roettger, Katrin and Gollhofer, Albert}, title = {Effects of core instability strength training on trunk muscle strength, spinal mobility, dynamic balance and functional mobility in older adults}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-399994}, pages = {9}, year = {2017}, abstract = {Background: Age-related postural misalignment, balance deficits and strength/power losses are associated with impaired functional mobility and an increased risk of falling in seniors. Core instability strength training (CIT) involves exercises that are challenging for both trunk muscles and postural control and may thus have the potential to induce benefits in trunk muscle strength, spinal mobility and balance performance. Objective: The objective was to investigate the effects of CIT on measures of trunk muscle strength, spinal mobility, dynamic balance and functional mobility in seniors. Methods: Thirty-two older adults were randomly assigned to an intervention group (INT; n = 16, aged 70.8 +/- 4.1 years) that conducted a 9-week progressive CIT or to a control group (n = 16, aged 70.2 +/- 4.5 years). Maximal isometric strength of the trunk flexors/extensors/lateral flexors (right, left)/rotators (right, left) as well as of spinal mobility in the sagittal and the coronal plane was measured before and after the intervention program. Dynamic balance (i.e. walking 10 m on an optoelectric walkway, the Functional Reach test) and functional mobility (Timed Up and Go test) were additionally tested. Results: Program compliance was excellent with participants of the INT group completing 92\% of the training sessions. Significant group x test interactions were found for the maximal isometric strength of the trunk flexors (34\%, p < 0.001), extensors (21\%, p < 0.001), lateral flexors (right: 48\%, p < 0.001; left: 53\%, p < 0.001) and left rotators (42\%, p < 0.001) in favor of the INT group. Further, training-related improvements were found for spinal mobility in the sagittal (11\%, p < 0.001) and coronal plane (11\%, p = 0.06) directions, for stride velocity (9\%, p < 0.05), the coefficient of variation in stride velocity (31\%, p < 0.05), the Functional Reach test (20\%, p < 0.05) and the Timed Up and Go test (4\%, p < 0.05) in favor of the INT group. Conclusion: CIT proved to be a feasible exercise program for seniors with a high adherence rate. Age-related deficits in measures of trunk muscle strength, spinal mobility, dynamic balance and functional mobility can be mitigated by CIT. This training regimen could be used as an adjunct or even alternative to traditional balance and/or resistance training.}, language = {en} } @misc{GranacherMuehlbauerBridenbaughetal.2017, author = {Granacher, Urs and M{\"u}hlbauer, Thomas and Bridenbaugh, Stephanie A. and Wolf, Madeleine and Roth, Ralf and Gschwind, Yves and Wolf, Irene and Mata, Rui and Kressig, Reto W.}, title = {Effects of a salsa dance training on balance and strength performance in older adults}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-399962}, pages = {8}, year = {2017}, abstract = {Background: Deficits in static and particularly dynamic postural control and force production have frequently been associated with an increased risk of falling in older adults. Objective: The objectives of this study were to investigate the effects of salsa dancing on measures of static/dynamic postural control and leg extensor power in seniors. Methods: Twenty-eight healthy older adults were randomly assigned to an intervention group (INT, n = 14, age 71.6 +/- 5.3 years) to conduct an 8-week progressive salsa dancing programme or a control group (CON, n = 14, age 68.9 +/- 4.7 years). Static postural control was measured during one-legged stance on a balance platform and dynamic postural control was obtained while walking on an instrumented walkway. Leg extensor power was assessed during a countermovement jump on a force plate. Results: Programme compliance was excellent with participants of the INT group completing 92.5\% of the dancing sessions. A tendency towards an improvement in the selected measures of static postural control was observed in the INT group as compared to the CON group. Significant group X test interactions were found for stride velocity, length and time. Post hoc analyses revealed significant increases in stride velocity and length, and concomitant decreases in stride time. However, salsa dancing did not have significant effects on various measures of gait variability and leg extensor power. Conclusion: Salsa proved to be a safe and feasible exercise programme for older adults accompanied with a high adherence rate. Age-related deficits in measures of static and particularly dynamic postural control can be mitigated by salsa dancing in older adults. High physical activity and fitness/mobility levels of our participants could be responsible for the nonsignificant findings in gait variability and leg extensor power.}, language = {en} } @misc{MuehlbauerBesemerWehrleetal.2017, author = {M{\"u}hlbauer, Thomas and Besemer, Carmen and Wehrle, Anja and Gollhofer, Albert and Granacher, Urs}, title = {Relationship between strength, power and balance performance in seniors}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-399970}, pages = {9}, year = {2017}, abstract = {Background: Deficits in strength, power and balance represent important intrinsic risk factors for falls in seniors. Objective: The purpose of this study was to investigate the relationship between variables of lower extremity muscle strength/power and balance, assessed under various task conditions. Methods: Twenty-four healthy and physically active older adults (mean age: 70 8 5 years) were tested for their isometric strength (i.e. maximal isometric force of the leg extensors) and muscle power (i.e. countermovement jump height and power) as well as for their steady-state (i.e. unperturbed standing, 10-meter walk), proactive (i.e. Timed Up \& Go test, Functional Reach Test) and reactive (i.e. perturbed standing) balance. Balance tests were conducted under single (i.e. standing or walking alone) and dual task conditions (i.e. standing or walking plus cognitive and motor interference task). Results: Significant positive correlations were found between measures of isometric strength and muscle power of the lower extremities (r values ranged between 0.608 and 0.720, p < 0.01). Hardly any significant associations were found between variables of strength, power and balance (i.e. no significant association in 20 out of 21 cases). Additionally, no significant correlations were found between measures of steady-state, proactive and reactive balance or balance tests performed under single and dual task conditions (all p > 0.05). Conclusion: The predominately nonsignificant correlations between different types of balance imply that balance performance is task specific in healthy and physically active seniors. Further, strength, power and balance as well as balance under single and dual task conditions seem to be independent of each other and may have to be tested and trained complementarily}, language = {en} } @misc{BeurskensMuehlbauerGranacheretal.2015, author = {Beurskens, Rainer and M{\"u}hlbauer, Thomas and Granacher, Urs and Gollhofer, Albert and Cardinale, Marco}, title = {Effects of heavy-resistance strength and balance training on unilateral and bilateral leg strength performance in old adults}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-73448}, pages = {13}, year = {2015}, abstract = {The term "bilateral deficit" (BLD) has been used to describe a reduction in performance during bilateral contractions when compared to the sum of identical unilateral contractions. In old age, maximal isometric force production (MIF) decreases and BLD increases indicating the need for training interventions to mitigate this impact in seniors. In a cross-sectional approach, we examined age-related differences in MIF and BLD in young (age: 20-30 years) and old adults (age: >65 years). In addition, a randomized-controlled trial was conducted to investigate training-specific effects of resistance vs. balance training on MIF and BLD of the leg extensors in old adults. Subjects were randomly assigned to resistance training (n = 19), balance training (n = 14), or a control group (n = 20). Bilateral heavy-resistance training for the lower extremities was performed for 13 weeks (3 × / week) at 80\% of the one repetition maximum. Balance training was conducted using predominately unilateral exercises on wobble boards, soft mats, and uneven surfaces for the same duration. Pre- and post-tests included uni- and bilateral measurements of maximal isometric leg extension force. At baseline, young subjects outperformed older adults in uni- and bilateral MIF (all p < .001; d = 2.61-3.37) and in measures of BLD (p < .001; d = 2.04). We also found significant increases in uni- and bilateral MIF after resistance training (all p < .001, d = 1.8-5.7) and balance training (all p < .05, d = 1.3-3.2). In addition, BLD decreased following resistance (p < .001, d = 3.4) and balance training (p < .001, d = 2.6). It can be concluded that both training regimens resulted in increased MIF and decreased BLD of the leg extensors (HRT-group more than BAL-group), almost reaching the levels of young adults.}, language = {en} } @misc{WerfelliHammamiSelmietal.2021, author = {Werfelli, Hanen and Hammami, Raouf and Selmi, Mohamed Amine and Selmi, Walid and Gabrilo, Goran and Clark, Cain C. T. and Duncan, Michael and Sekulic, Damir and Granacher, Urs and Rebai, Haithem}, title = {Acute Effects of Different Plyometric and Strength Exercises on Balance Performance in Youth Weightlifters}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, issn = {1866-8364}, doi = {10.25932/publishup-54310}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-543109}, pages = {11}, year = {2021}, abstract = {Background: High-intensity muscle actions have the potential to temporarily improve the performance which has been denoted as postactivation performance enhancement. Objectives: This study determined the acute effects of different stretch-shortening (fast vs. low) and strength (dynamic vs. isometric) exercises executed during one training session on subsequent balance performance in youth weightlifters. Materials and Methods: Sixteen male and female young weightlifters, aged 11.3±0.6years, performed four strength exercise conditions in randomized order, including dynamic strength (DYN; 3 sets of 3 repetitions of 10 RM) and isometric strength exercises (ISOM; 3 sets of maintaining 3s of 10 RM of back-squat), as well as fast (FSSC; 3 sets of 3 repetitions of 20-cm drop-jumps) and slow (SSSC; 3 sets of 3 hurdle jumps over a 20-cm obstacle) stretch-shortening cycle protocols. Balance performance was tested before and after each of the four exercise conditions in bipedal stance on an unstable surface (i.e., BOSU ball with flat side facing up) using two dependent variables, i.e., center of pressure surface area (CoP SA) and velocity (CoP V). Results: There was a significant effect of time on CoP SA and CoP V [F(1,60)=54.37, d=1.88, p<0.0001; F(1,60)=9.07, d=0.77, p=0.003]. In addition, a statistically significant effect of condition on CoP SA and CoP V [F(3,60)=11.81, d=1.53, p<0.0001; F(3,60)=7.36, d=1.21, p=0.0003] was observed. Statistically significant condition-by-time interactions were found for the balance parameters CoP SA (p<0.003, d=0.54) and CoP V (p<0.002, d=0.70). Specific to contrast analysis, all specified hypotheses were tested and demonstrated that FSSC yielded significantly greater improvements than all other conditions in CoP SA and CoP V [p<0.0001 (d=1.55); p=0.0004 (d=1.19), respectively]. In addition, FSSC yielded significantly greater improvements compared with the two conditions for both balance parameters [p<0.0001 (d=2.03); p<0.0001 (d=1.45)]. Conclusion: Fast stretch-shortening cycle exercises appear to be more effective to improve short-term balance performance in young weightlifters. Due to the importance of balance for overall competitive achievement in weightlifting, it is recommended that young weightlifters implement dynamic plyometric exercises in the fast stretch-shortening cycle during the warm-up to improve their balance performance.}, language = {en} } @misc{GranacherNobariRuivoAlvesetal.2020, author = {Granacher, Urs and Nobari, Hadi and Ruivo Alves, Ana and Clemente, Filipe Manuel and P{\´e}rez-G{\´o}mez, Jorge and Clark, Cain Craig Truman and Zouhal, Hassane}, title = {Associations Between Variations in Accumulated Workload and Physiological Variables in Young Male Soccer Players Over the Course of a Season}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, publisher = {Universit{\"a}t Potsdam}, address = {Potsdam}, issn = {1866-8364}, doi = {10.25932/publishup-54044}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-540440}, pages = {1 -- 12}, year = {2020}, abstract = {This study sought to analyze the relationship between in-season training workload with changes in aerobic power (VO2max), maximum and resting heart rate (HRmax and HRrest), linear sprint medium (LSM), and short test (LSS), in soccer players younger than 16 years (under-16 soccer players). We additionally aimed to explain changes in fitness levels during the in-season through regression models, considering accumulated load, baseline levels, and peak height velocity (PHV) as predictors. Twenty-three male sub-elite soccer players aged 15.5 ± 0.2 years (PHV: 13.6 ± 0.4 years; body height: 172.7 ± 4.2 cm; body mass: 61.3 ± 5.6 kg; body fat: 13.7\% ± 3.9\%; VO2max: 48.4 ± 2.6 mL⋅kg-1⋅min-1), were tested three times across the season (i.e., early-season (EaS), mid-season (MiS), and end-season (EnS) for VO2max, HRmax, LSM, and LSS. Aerobic and speed variables gradually improved over the season and had a strong association with PHV. Moreover, the HRmax demonstrated improvements from EaS to EnS; however, this was more evident in the intermediate period (from EaS to MiS) and had a strong association with VO2max. Regression analysis showed significant predictions for VO2max [F(2, 20) = 8.18, p ≤ 0.001] with an R2 of 0.45. In conclusion, the meaningful variation of youth players' fitness levels can be observed across the season, and such changes can be partially explained by the load imposed.}, language = {en} } @misc{ElAshkerChaabenePrieskeetal.2019, author = {El-Ashker, Said and Chaabene, Helmi and Prieske, Olaf and Abdelkafy, Ashraf and Ahmed, Mohamed A. and Muaidi, Qassim I. and Granacher, Urs}, title = {Effects of Neuromuscular Fatigue on Eccentric Strength and Electromechanical Delay of the Knee Flexors}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {562}, issn = {1866-8364}, doi = {10.25932/publishup-43586}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435863}, pages = {9}, year = {2019}, abstract = {Purpose: To examine the effects of fatiguing isometric contractions on maximal eccentric strength and electromechanical delay (EMD) of the knee flexors in healthy young adults of different training status. Methods: Seventy-five male participants (27.7 ± 5.0 years) were enrolled in this study and allocated to three experimental groups according to their training status: athletes (ATH, n = 25), physically active adults (ACT, n = 25), and sedentary participants (SED, n = 25). The fatigue protocol comprised intermittent isometric knee flexions (6-s contraction, 4-s rest) at 60\% of the maximum voluntary contraction until failure. Pre- and post-fatigue, maximal eccentric knee flexor strength and EMDs of the biceps femoris, semimembranosus, and semitendinosus muscles were assessed during maximal eccentric knee flexor actions at 60, 180, and 300°/s angular velocity. An analysis of covariance was computed with baseline (unfatigued) data included as a covariate. Results: Significant and large-sized main effects of group (p ≤ 0.017, 0.87 ≤ d ≤ 3.69) and/or angular velocity (p < 0.001, d = 1.81) were observed. Post hoc tests indicated that regardless of angular velocity, maximal eccentric knee flexor strength was lower and EMD was longer in SED compared with ATH and ACT (p ≤ 0.025, 0.76 ≤ d ≤ 1.82) and in ACT compared with ATH (p = ≤0.025, 0.76 ≤ d ≤ 1.82). Additionally, EMD at post-test was significantly longer at 300°/s compared with 60 and 180°/s (p < 0.001, 2.95 ≤ d ≤ 4.64) and at 180°/s compared with 60°/s (p < 0.001, d = 2.56), irrespective of training status. Conclusion: The main outcomes revealed significantly higher maximal eccentric strength and shorter eccentric EMDs of knee flexors in individuals with higher training status (i.e., athletes) following fatiguing exercises. Therefore, higher training status is associated with better neuromuscular functioning (i.e., strength, EMD) of the hamstring muscles in fatigued condition. Future longitudinal studies are needed to substantiate the clinical relevance of these findings.}, language = {en} } @misc{BeurskensSteinbergAntoniewiczetal.2016, author = {Beurskens, Rainer and Steinberg, Fabian and Antoniewicz, Franziska and Wolff, Wanja and Granacher, Urs}, title = {Neural Correlates of Dual-Task Walking}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90742}, pages = {1 -- 9}, year = {2016}, abstract = {Walking while concurrently performing cognitive and/or motor interference tasks is the norm rather than the exception during everyday life and there is evidence from behavioral studies that it negatively affects human locomotion. However, there is hardly any information available regarding the underlying neural correlates of single- and dual-task walking. We had 12 young adults (23.8 ± 2.8 years) walk while concurrently performing a cognitive interference (CI) or a motor interference (MI) task. Simultaneously, neural activation in frontal, central, and parietal brain areas was registered using a mobile EEG system. Results showed that the MI task but not the CI task affected walking performance in terms of significantly decreased gait velocity and stride length and significantly increased stride time and tempo-spatial variability. Average activity in alpha and beta frequencies was significantly modulated during both CI and MI walking conditions in frontal and central brain regions, indicating an increased cognitive load during dual-task walking. Our results suggest that impaired motor performance during dual-task walking is mirrored in neural activation patterns of the brain. This finding is in line with established cognitive theories arguing that dual-task situations overstrain cognitive capabilities resulting in motor performance decrements.}, language = {en} } @misc{FernandezFernandezGranacherMartinezMartinetal.2022, author = {Fernandez-Fernandez, Jaime and Granacher, Urs and Martinez-Martin, Isidoro and Garcia-Tormo, Jos{\´e} Vicente and Herrero-Molleda, Alba and Barbado, David and Garc{\´i}a L{\´o}pez, Juan}, title = {Physical fitness and throwing speed in U13 versus U15 male handball players}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {803}, issn = {1866-8364}, doi = {10.25932/publishup-56730}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-567307}, pages = {13}, year = {2022}, abstract = {Background The aim of this study was to analyze the shoulder functional profile (rotation range of motion [ROM] and strength), upper and lower body performance, and throwing speed of U13 versus U15 male handball players, and to establish the relationship between these measures of physical fitness and throwing speed. Methods One-hundred and nineteen young male handball players (under (U)-13 (U13) [n = 85]) and U15 [n = 34]) volunteered to participate in this study. The participating athletes had a mean background of sytematic handball training of 5.5 ± 2.8 years and they exercised on average 540 ± 10.1 min per week including sport-specific team handball training and strength and conditioning programs. Players were tested for passive shoulder range-of-motion (ROM) for both internal (IR) and external rotation (ER) and isometric strength (i.e., IR and ER) of the dominant/non-dominant shoulders, overhead medicine ball throw (OMB), hip isometric abductor (ABD) and adductor (ADD) strength, hip ROM, jumps (countermovement jump [CMJ] and triple leg-hop [3H] for distance), linear sprint test, modified 505 change-of-direction (COD) test and handball throwing speed (7 m [HT7] and 9 m [HT9]). Results U15 players outperformed U13 in upper (i.e., HT7 and HT9 speed, OMB, absolute IR and ER strength of the dominant and non-dominant sides; Cohen's d: 0.76-2.13) and lower body (i.e., CMJ, 3H, 20-m sprint and COD, hip ABD and ADD; d: 0.70-2.33) performance measures. Regarding shoulder ROM outcomes, a lower IR ROM was found of the dominant side in the U15 group compared to the U13 and a higher ER ROM on both sides in U15 (d: 0.76-1.04). It seems that primarily anthropometric characteristics (i.e., body height, body mass) and upper body strength/power (OMB distance) are the most important factors that explain the throw speed variance in male handball players, particularly in U13. Conclusions Findings from this study imply that regular performance monitoring is important for performance development and for minimizing injury risk of the shoulder in both age categories of young male handball players. Besides measures of physical fitness, anthropometric data should be recorded because handball throwing performance is related to these measures.}, language = {en} } @misc{JafarnezhadgeroNorooziFakhriMirzanagetal.2022, author = {Jafarnezhadgero, Amir Ali and Noroozi, Raha and Fakhri Mirzanag, Ehsan and Granacher, Urs and de Souza Castelo Oliveira, Anderson}, title = {The Impact of COVID-19 and Muscle Fatigue on Cardiorespiratory Fitness and Running Kinetics in Female Recreational Runners}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {806}, issn = {1866-8364}, doi = {10.25932/publishup-57202}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-572020}, pages = {10}, year = {2022}, abstract = {Background: There is evidence that fully recovered COVID-19 patients usually resume physical exercise, but do not perform at the same intensity level performed prior to infection. The aim of this study was to evaluate the impact of COVID-19 infection and recovery as well as muscle fatigue on cardiorespiratory fitness and running biomechanics in female recreational runners. Methods: Twenty-eight females were divided into a group of hospitalized and recovered COVID-19 patients (COV, n = 14, at least 14 days following recovery) and a group of healthy age-matched controls (CTR, n = 14). Ground reaction forces from stepping on a force plate while barefoot overground running at 3.3 m/s was measured before and after a fatiguing protocol. The fatigue protocol consisted of incrementally increasing running speed until reaching a score of 13 on the 6-20 Borg scale, followed by steady-state running until exhaustion. The effects of group and fatigue were assessed for steady-state running duration, steady-state running speed, ground contact time, vertical instantaneous loading rate and peak propulsion force. Results: COV runners completed only 56\% of the running time achieved by the CTR (p < 0.0001), and at a 26\% slower steady-state running speed (p < 0.0001). There were fatigue-related reductions in loading rate (p = 0.004) without group differences. Increased ground contact time (p = 0.002) and reduced peak propulsion force (p = 0.005) were found for COV when compared to CTR. Conclusion: Our results suggest that female runners who recovered from COVID-19 showed compromised running endurance and altered running kinetics in the form of longer stance periods and weaker propulsion forces. More research is needed in this area using larger sample sizes to confirm our study findings.}, language = {en} } @misc{SandauChaabeneGranacher2021, author = {Sandau, Ingo and Chaabene, Helmi and Granacher, Urs}, title = {Concurrent validity of barbell force measured from video-based barbell kinematics during the snatch in male elite weightlifters}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {716}, issn = {1866-8364}, doi = {10.25932/publishup-52167}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-521678}, pages = {13}, year = {2021}, abstract = {This study examined the concurrent validity of an inverse dynamic (force computed from barbell acceleration [reference method]) and a work-energy (force computed from work at the barbell [alternative method]) approach to measure the mean vertical barbell force during the snatch using kinematic data from video analysis. For this purpose, the acceleration phase of the snatch was analyzed in thirty male medal winners of the 2018 weightlifting World Championships (age: 25.2±3.1 years; body mass: 88.9±28.6 kg). Vertical barbell kinematics were measured using a custom-made 2D real-time video analysis software. Agreement between the two computational approaches was assessed using Bland-Altman analysis, Deming regression, and Pearson product-moment correlation. Further, principal component analysis in conjunction with multiple linear regression was used to assess whether individual differences related to the two approaches are due to the waveforms of the acceleration time-series data. Results indicated no mean difference (p > 0.05; d = -0.04) and an extremely large correlation (r = 0.99) between the two approaches. Despite the high agreement, the total error of individual differences was 8.2\% (163.0 N). The individual differences can be explained by a multiple linear regression model (R2adj = 0.86) on principal component scores from the principal component analysis of vertical barbell acceleration time-series waveforms. Findings from this study indicate that the individual errors of force measures can be associated with the inverse dynamic approach. This approach uses vertical barbell acceleration data from video analysis that is prone to error. Therefore, it is recommended to use the work-energy approach to compute mean vertical barbell force as this approach did not rely on vertical barbell acceleration.}, language = {en} } @misc{LesinskiSchmelcherHerzetal.2020, author = {Lesinski, Melanie and Schmelcher, Alina and Herz, Michael and Puta, Christian and Gabriel, Holger and Arampatzis, Adamantios and Laube, Gunnar and B{\"u}sch, Dirk and Granacher, Urs}, title = {Maturation-, age-, and sex-specific anthropometric and physical fitness percentiles of German elite young athletes}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {662}, issn = {1866-8364}, doi = {10.25932/publishup-48026}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-480268}, pages = {21}, year = {2020}, abstract = {The aim of this study was to establish maturation-, age-, and sex-specific anthropometric and physical fitness percentile reference values of young elite athletes from various sports. Anthropometric (i.e., standing and sitting body height, body mass, body mass index) and physical fitness (i.e., countermovement jump, drop jump, change-of-direction speed [i.e., T-test], trunk muscle endurance [i.e., ventral Bourban test], dynamic lower limbs balance [i.e., Y-balance test], hand grip strength) of 703 male and female elite young athletes aged 8-18 years were collected to aggregate reference values according to maturation, age, and sex. Findings indicate that body height and mass were significantly higher (p<0.001; 0.95≤d≤1.74) in more compared to less mature young athletes as well as with increasing chronological age (p<0.05; 0.66≤d≤3.13). Furthermore, male young athletes were significantly taller and heavier compared to their female counterparts (p<0.001; 0.34≤d≤0.50). In terms of physical fitness, post-pubertal athletes showed better countermovement jump, drop jump, change-of-direction, and handgrip strength performances (p<0.001; 1.57≤d≤8.72) compared to pubertal athletes. Further, countermovement jump, drop jump, change-of-direction, and handgrip strength performances increased with increasing chronological age (p<0.05; 0.29≤d≤4.13). In addition, male athletes outperformed their female counterpart in the countermovement jump, drop jump, change-of-direction, and handgrip strength (p<0.05; 0.17≤d≤0.76). Significant age by sex interactions indicate that sex-specific differences were even more pronounced with increasing age. Conclusively, body height, body mass, and physical fitness increased with increasing maturational status and chronological age. Sex-specific differences appear to be larger as youth grow older. Practitioners can use the percentile values as approximate benchmarks for talent identification and development.}, language = {en} } @misc{ZouitaZouhalFerchichietal.2020, author = {Zouita, Sghaier and Zouhal, Hassane and Ferchichi, Habiba and Paillard, Thierry and Dziri, Catherine and Hackney, Anthony C. and Laher, Ismail and Granacher, Urs and Ben Moussa Zouita, Amira}, title = {Effects of Combined Balance and Strength Training on Measures of Balance and Muscle Strength in Older Women With a History of Falls}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {699}, issn = {1866-8364}, doi = {10.25932/publishup-49093}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-490932}, pages = {15}, year = {2020}, abstract = {Objective: We investigated the effects of combined balance and strength training on measures of balance and muscle strength in older women with a history of falls. Methods: Twenty-seven older women aged 70.4 ± 4.1 years (age range: 65 to 75 years) were randomly allocated to either an intervention (IG, n = 12) or an active control (CG, n = 15) group. The IG completed 8 weeks combined balance and strength training program with three sessions per week including visual biofeedback using force plates. The CG received physical therapy and gait training at a rehabilitation center. Training volumes were similar between the groups. Pre and post training, tests were applied for the assessment of muscle strength (weight-bearing squat [WBS] by measuring the percentage of body mass borne by each leg at different knee flexions [0°, 30°, 60°, and 90°], sit-to-stand test [STS]), and balance. Balance tests used the modified clinical test of sensory interaction (mCTSIB) with eyes closed (EC) and opened (EO), on stable (firm) and unstable (foam) surfaces as well as spatial parameters of gait such as step width and length (cm) and walking speed (cm/s). Results: Significant group × time interactions were found for different degrees of knee flexion during WBS (0.0001 < p < 0.013, 0.441 < d < 0.762). Post hoc tests revealed significant pre-to-post improvements for both legs and for all degrees of flexion (0.0001 < p < 0.002, 0.697 < d < 1.875) for IG compared to CG. Significant group × time interactions were found for firm EO, foam EO, firm EC, and foam EC (0.006 < p < 0.029; 0.302 < d < 0.518). Post hoc tests showed significant pre-to-post improvements for both legs and for all degrees of oscillations (0.0001 < p < 0.004, 0.753 < d < 2.097) for IG compared to CG. This study indicates that combined balance and strength training improved percentage distribution of body weight between legs at different conditions of knee flexion (0°, 30°, 60°, and 90°) and also decreased the sway oscillation on a firm surface with eyes closed, and on foam surface (with eyes opened or closed) in the IG. Conclusion: The higher positive effects of training seen in standing balance tests, compared with dynamic tests, suggests that balance training exercises including lateral, forward, and backward exercises improved static balance to a greater extent in older women.}, language = {en} } @misc{JafarnezhadgeroAlaviMehrGranacher2019, author = {Jafarnezhadgero, Amir Ali and Alavi-Mehr, Seyed Majid and Granacher, Urs}, title = {Effects of anti-pronation shoes on lower limb kinematics and kinetics in female runners with pronated feet}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {560}, issn = {1866-8364}, doi = {10.25932/publishup-43541}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435415}, pages = {14}, year = {2019}, abstract = {Physical fatigue and pronated feet constitute two risk factors for running-related lower limb injuries. Accordingly, different running shoe companies designed anti-pronation shoes with medial support to limit over pronation in runners. However, there is little evidence on the effectiveness and clinical relevance of anti-pronation shoes. This study examined lower limb kinematics and kinetics in young female runners with pronated feet during running with antipronation versus regular (neutral) running shoes in unfatigued and fatigued condition. Twenty-six female runners aged 24.1±5.6 years with pronated feet volunteered to participate in this study. Kinetic (3D Kistler force plate) and kinematic analyses (Vicon motion analysis system) were conducted to record participants' ground reaction forces and joint kinematics when running with anti-pronation compared with neutral running shoes. Physical fatigue was induced through an individualized submaximal running protocol on a motorized treadmill using rate of perceived exertion and heart rate monitoring. The statistical analyses indicated significant main effects of "footwear" for peak ankle inversion, peak ankle eversion, and peak hip internal rotation angles (p<0.03; d = 0.46-0.95). Pair-wise comparisons revealed a significantly greater peak ankle inversion angle (p<0.03; d = 0.95; 2.70°) and smaller peak eversion angle (p<0.03; d = 0.46; 2.53°) when running with anti-pronation shoes compared with neutral shoes. For kinetic data, significant main effects of "footwear" were found for peak ankle dorsiflexor moment, peak knee extensor moment, peak hip flexor moment, peak hip extensor moment, peak hip abductor moment, and peak hip internal rotator moment (p<0.02; d = 1.00-1.79). For peak positive hip power in sagittal and frontal planes and peak negative hip power in horizontal plane, we observed significant main effects of "footwear" (p<0.03; d = 0.92-1.06). Pairwise comparisons revealed that peak positive hip power in sagittal plane (p<0.03; d = 0.98; 2.39 w/kg), peak positive hip power in frontal plane (p = 0.014; d = 1.06; 0.54 w/kg), and peak negative hip power in horizontal plane (p<0.03; d = 0.92; 0.43 w/kg) were greater with anti-pronation shoes. Furthermore, the statistical analyses indicated significant main effects of "Fatigue" for peak ankle inversion, peak ankle eversion, and peak knee external rotation angles. Pair-wise comparisons revealed a fatigue-induced decrease in peak ankle inversion angle (p<0.01; d = 1.23; 2.69°) and a fatigue-induced increase in peak knee external rotation angle (p<0.05; d = 0.83; 5.40°). In addition, a fatigue-related increase was found for peak ankle eversion (p<0.01; d = 1.24; 2.67°). For kinetic data, we observed a significant main effect of "Fatigue" for knee flexor moment, knee internal rotator moment, and hip extensor moment (p<0.05; d = 0.83-1.01). The statistical analyses indicated significant a main effect of "Fatigue" for peak negative ankle power in sagittal plane (p<0.01; d = 1.25). Finally, we could not detect any significant footwear by fatigue interaction effects for all measures of joint kinetics and kinematics. Running in anti-pronation compared with neutral running shoes produced lower peak moments and powers in lower limb joints and better control in rear foot eversion. Physical fatigue increased peak moments and powers in lower limb joints irrespective of the type of footwear.}, language = {en} } @misc{GschwindKressigLacroixetal.2013, author = {Gschwind, Yves J. and Kressig, Reto W. and Lacroix, Andre and M{\"u}hlbauer, Thomas and Pfenninger, Barbara and Granacher, Urs}, title = {A best practice fall prevention exercise program to improve balance, strength/power, and psychosocial health in older adults}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {604}, issn = {1866-8364}, doi = {10.25932/publishup-42710}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427104}, pages = {15}, year = {2013}, abstract = {Background: With increasing age neuromuscular deficits (e.g., sarcopenia) may result in impaired physical performance and an increased risk for falls. Prominent intrinsic fall-risk factors are age-related decreases in balance and strength / power performance as well as cognitive decline. Additional studies are needed to develop specifically tailored exercise programs for older adults that can easily be implemented into clinical practice. Thus, the objective of the present trial is to assess the effects of a fall prevention program that was developed by an interdisciplinary expert panel on measures of balance, strength / power, body composition, cognition, psychosocial well-being, and falls self-efficacy in healthy older adults. Additionally, the time-related effects of detraining are tested. Methods/Design: Healthy old people (n = 54) between the age of 65 to 80 years will participate in this trial. The testing protocol comprises tests for the assessment of static / dynamic steady-state balance (i.e., Sharpened Romberg Test, instrumented gait analysis), proactive balance (i.e., Functional Reach Test; Timed Up and Go Test), reactive balance (i.e., perturbation test during bipedal stance; Push and Release Test), strength (i.e., hand grip strength test; Chair Stand Test), and power (i.e., Stair Climb Power Test; countermovement jump). Further, body composition will be analysed using a bioelectrical impedance analysis system. In addition, questionnaires for the assessment of psychosocial (i.e., World Health Organisation Quality of Life Assessment-Bref), cognitive (i.e., Mini Mental State Examination), and fall risk determinants (i.e., Fall Efficacy Scale -International) will be included in the study protocol. Participants will be randomized into two intervention groups or the control / waiting group. After baseline measures, participants in the intervention groups will conduct a 12-week balance and strength / power exercise intervention 3 times per week, with each training session lasting 30 min. (actual training time). One intervention group will complete an extensive supervised training program, while the other intervention group will complete a short version (` 3 times 3') that is home-based and controlled by weekly phone calls. Post-tests will be conducted right after the intervention period. Additionally, detraining effects will be measured 12 weeks after program cessation. The control group / waiting group will not participate in any specific intervention during the experimental period, but will receive the extensive supervised program after the experimental period. Discussion: It is expected that particularly the supervised combination of balance and strength / power training will improve performance in variables of balance, strength / power, body composition, cognitive function, psychosocial well-being, and falls self-efficacy of older adults. In addition, information regarding fall risk assessment, dose-response-relations, detraining effects, and supervision of training will be provided. Further, training-induced health-relevant changes, such as improved performance in activities of daily living, cognitive function, and quality of life, as well as a reduced risk for falls may help to lower costs in the health care system. Finally, practitioners, therapists, and instructors will be provided with a scientifically evaluated feasible, safe, and easy-to-administer exercise program for fall prevention.}, language = {en} } @misc{ThielePrieskeLesinskietal.2020, author = {Thiele, Dirk and Prieske, Olaf and Lesinski, Melanie and Granacher, Urs}, title = {Effects of Equal Volume Heavy-Resistance Strength Training Versus Strength Endurance Training on Physical Fitness and Sport-Specific Performance in Young Elite Female Rowers}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {664}, issn = {1866-8364}, doi = {10.25932/publishup-48196}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-481961}, pages = {14}, year = {2020}, abstract = {Strength training is an important means for performance development in young rowers. The purpose of this study was to examine the effects of a 9-week equal volume heavy-resistance strength training (HRST) versus strength endurance training (SET) in addition to regular rowing training on primary (e.g., maximal strength/power) and secondary outcomes (e.g., balance) in young rowers. Twenty-six female elite adolescent rowers were assigned to an HRST (n = 12; age: 13.2 ± 0.5 yrs; maturity-offset: +2.0 ± 0.5 yrs) or a SET group (n = 14; age: 13.1 ± 0.5 yrs; maturity-offset: +2.1 ± 0.5 yrs). HRST and SET comprised lower- (i.e., leg press/knee flexion/extension), upper-limbs (i.e., bench press/pull; lat-pull down), and complex exercises (i.e., rowing ergometer). HRST performed four sets with 12 repetitions per set at an intensity of 75-95\% of the one-repetition maximum (1-RM). SET conducted four sets with 30 repetitions per set at 50-60\% of the 1-RM. Training volume was matched for overall repetitions × intensity × training per week. Pre-post training, tests were performed for the assessment of primary [i.e., maximal strength (e.g., bench pull/knee flexion/extension 1-RM/isometric handgrip test), muscle power (e.g., medicine-ball push test, triple hop, drop jump, and countermovement jump), anaerobic endurance (400-m run), sport-specific performance (700-m rowing ergometer trial)] and secondary outcomes [dynamic balance (Y-balance test), change-of-direction (CoD) speed (multistage shuttle-run test)]. Adherence rate was >87\% and one athlete of each group dropped out. Overall, 24 athletes completed the study and no test or training-related injuries occurred. Significant group × time interactions were observed for maximal strength, muscle power, anaerobic endurance, CoD speed, and sport-specific performance (p ≤ 0.05; 0.45 ≤ d ≤ 1.11). Post hoc analyses indicated larger gains in maximal strength and muscle power following HRST (p ≤ 0.05; 1.81 ≤ d ≤ 3.58) compared with SET (p ≤ 0.05; 1.04 ≤ d ≤ 2.30). Furthermore, SET (p ≤ 0.01; d = 2.08) resulted in larger gains in sport-specific performance compared with HRST (p < 0.05; d = 1.3). Only HRST produced significant pre-post improvements for anaerobic endurance and CoD speed (p ≤ 0.05; 1.84 ≤ d ≤ 4.76). In conclusion, HRST in addition to regular rowing training was more effective than SET to improve selected measures of physical fitness (i.e., maximal strength, muscle power, anaerobic endurance, and CoD speed) and SET was more effective than HRST to enhance sport-specific performance gains in female elite young rowers.}, language = {en} }