TY - JOUR A1 - Jafarnezhadgero, AmirAli A1 - Ghorbanloo, Farshad A1 - Fatollahi, Amir A1 - Dionisio, Valdeci Carlos A1 - Granacher, Urs T1 - Effects of an elastic resistance band exercise program on kinetics and muscle activities during walking in young adults with genu valgus BT - A double-blinded randomized controlled trial JF - Clinical biomechanics : a journal affiliated to the International Society of Biomechanics and the American Society of Biomechanics N2 - Background: This double-blinded randomized-controlled-trial aimed to identify the effects of an elastic band resistance training on walking kinetics and muscle activities in young adults with genu valgus. Methods: Forty-two male young adults aged 22.5(2.7) years with genu valgus were randomly allocated to two experimental groups. The intervention group (n = 21) conducted a 14-weeks elastic band resistance training. The control group was passive during the intervention period and received the same treatment after the post-tests. Pre and post training, ground reaction forces and lower limb muscle activities were recorded during walking. Findings: Results revealed significant group-by-time interactions for peak medial ground reaction force and timeto-peak for posterior ground reaction force in favor of the intervention group (p < 0.012; d = 0.83-3.76). Resistance training with elastic bands resulted in significantly larger peak medial ground reaction force (p < 0.001; d = 1.45) and longer time-to-peak for posterior ground reaction force (p < 0.001; d = 1.85). Finding showed significant group-by-time interactions for peak positive free moment amplitudes in favor of the intervention group (p < 0.001; d = 1.18-2.02). Resistance training resulted in a lower peak positive free moment amplitude (p = 0.001; d = 1.46). With regards to muscle activities, the analysis revealed significant group-by time interactions for rectus femoris and gluteus medius activities during the push-off phase in favor of the intervention group (p < 0.038; d = 0.68-0.89). Resistance training induced higher rectus femoris (p = 0.038; d = 0.84) and gluteus medius (p = 0.007; d = 0.54) activities. Interpretation: This study proved the effectiveness of resistance training using elastic bands on kinetics and muscle activities during walking in male adults with genu valgus disorder. Given that this training regime is low cost, effective, and easy-to-administer, we suggest that it should be implemented as a rehabilitative or preventive means for young adults with genu valgus. KW - Free moment KW - Gait KW - Knee valgus KW - Loading rate KW - Theraband training Y1 - 2021 U6 - https://doi.org/10.1016/j.clinbiomech.2020.105215 SN - 0268-0033 SN - 1879-1271 VL - 81 PB - Elsevier Science CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Wick, Kristin A1 - Kriemler, Susi A1 - Granacher, Urs T1 - Effects of a strength-dominated exercise program on physical fitness and cognitive performance in preschool children JF - Journal of strength and conditioning research : the research journal of the NSCA N2 - Wick, K, Kriemler, S, and Granacher, U. Effects of a strength-dominated exercise program on physical fitness and cognitive performance in preschool children. J Strength Cond Res 35(4): 983-990, 2021-Childhood is characterized by high neuroplasticity that affords qualitative rather than quantitative components of physical activity to maximize the potential to sufficiently develop motor skills and foster long-term engagement in regular physical activity. This study examined the effects of an integrative strength-dominated exercise program on measures of physical fitness and cognitive performance in preschool children. Children aged 4-6 years from 3 kindergartens were randomized into an intervention (INT) group (n = 32) or a control group (n = 22). The 10-week intervention period was conducted 3 times per week (each session lasted 30 minutes) and included exercises for the promotion of muscle strength and power, coordination, and balance. Pre and post training, tests were conducted for the assessment of muscle strength (i.e., handgrip strength), muscle power (i.e., standing long jump), balance (i.e., timed single-leg stand), coordination (hopping on right/left leg), and attentional span (i.e., "Konzentrations-Handlungsverfahren fur Vorschulkinder" [concentration-action procedure for preschoolers]). Results from 2 x 2 repeated-measures analysis of covariance revealed a significant (p <= 0.05) and near significant (p = 0.051) group x time interaction for the standing long jump test and the Konzentrations-Handlungsverfahren. Post hoc tests showed significant pre-post changes for the INT (p < 0.001; d = 1.53) but not the CON (p = 0.72; d = 0.83). Our results indicate that a 10-week strength-dominated exercise program increased jump performance with a concomitant trend toward improvements in attentional capacity of preschool children. Thus, we recommend implementing this type of exercise program for preschoolers. KW - motor skills KW - cognitive skills KW - attention KW - kindergarten KW - structured KW - physical activity program Y1 - 2021 U6 - https://doi.org/10.1519/JSC.0000000000003942 SN - 1064-8011 SN - 1533-4287 VL - 35 IS - 4 SP - 983 EP - 990 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Chaabene, Helmi A1 - Negra, Yassine A1 - Moran, Jason A1 - Prieske, Olaf A1 - Sammoud, Senda A1 - Ramirez-Campillo, Rodrigo A1 - Granacher, Urs T1 - Plyometric training improves not only measures of linear speed, power, and change-of-direction speed but also repeated sprint ability in young female handball players JF - Journal of strength and conditioning research : the research journal of the NSCA N2 - This study examined the effects of an 8-week plyometric training (PT) program on components of physical fitness in young female handball players. Twenty-one female adolescent handball players were assigned to an experimental group (EG, n = 12; age = 15.9 +/- 0.2 years) or an active control group (CG, n = 9, age = 15.9 +/- 0.3 years). While EG performed plyometric exercises in replacement of some handball-specific drills, CG maintained the regular training schedule. Baseline and follow-up tests were performed for the assessment of linear speed (i.e., 5-, 10-, and 20-m time), change-of-direction (CoD) speed (i.e., T-test time), muscle power (i.e., countermovement jump [CMJ] height and reactive strength index [RSI]), and repeated sprint ability (RSA) (RSA total time [RSA(total)], RSA best time [RSA(best)], and RSA fatigue index [RSA(FI)]). Data were analyzed using magnitude-based inferences. Within-group analyses for the EG revealed moderate-to-large improvements for the 5-m (effect size [ES] = 0.81 [0.1-1.5]), 10-m sprint time (ES = 0.84 [0.1-1.5]), RSI (ES = 0.75 [0.1-1.4]), RSA(FI) (ES = 0.65 [0.0-1.3]), and T-test time (ES = 1.46 [0.7-2.2]). Trivial-to-small ES was observed for RSA(best) (ES = 0.18 [-0.5 to 0.9]), RSA(total) (ES = 0.45 [-0.2 to 1.1]), 20-m sprint time (ES = 0.56 [-0.1 to 1.2]), and CMJ height (ES = 0.57 [-0.1 to 1.3]). For the CG, within-group analyses showed a moderate performance decline for T-test time (ES = -0.71 [-1.5 to 0.1]), small decreases for 5-m sprint time (ES = -0.46 [-1.2 to 0.3]), and a trivial decline for 10-m (ES = -0.10 [-0.9 to 0.7]) and 20-m sprint times (ES = -0.16 [-0.9 to 0.6]), RSA(total) (ES = 0.0 [-0.8 to 0.8]), and RSA(best) (ES = -0.20 [-0.9 to 0.6]). The control group achieved trivial-to-small improvements for CMJ height (ES = 0.10 [-0.68 to 0.87]) and RSI (ES = 0.30 [-0.5 to 1.1]). In conclusion, a short-term in-season PT program, in replacement of handball-specific drills, is effective in improving measures of physical fitness (i.e., linear/CoD speed, jumping, and RSA) in young female handball players. KW - stretch-shortening cycle KW - physical fitness KW - young athletes Y1 - 2021 U6 - https://doi.org/10.1519/JSC.0000000000003128 SN - 1064-8011 SN - 1533-4287 VL - 35 IS - 8 SP - 2230 EP - 2235 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Jafarnezhadgero, Amir Ali A1 - Noroozi, Raha A1 - Fakhri, Ehsan A1 - Granacher, Urs A1 - Oliveira, Anderson Souza T1 - The Impact of COVID-19 and muscle fatigue on cardiorespiratory fitness and running kinetics in female recreational runners JF - Frontiers in physiology N2 - 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. KW - hospitalization KW - running mechanics KW - ground reaction forces KW - virus KW - infection KW - COVID-19 Y1 - 2022 U6 - https://doi.org/10.3389/fphys.2022.942589 SN - 1664-042X VL - 13 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Hortobágyi, Tibor A1 - Vetrovsky, Tomas A1 - Balbim, Guilherme Moraes A1 - Sorte Silva, Narlon Cassio Boa A1 - Manca, Andrea A1 - Deriu, Franca A1 - Kolmos, Mia A1 - Kruuse, Christina A1 - Liu-Ambrose, Teresa A1 - Radak, Zsolt A1 - Vaczi, Mark A1 - Johansson, Hanna A1 - Rocha dos Santos, Paulo Cezar A1 - Franzen, Erika A1 - Granacher, Urs T1 - The impact of aerobic and resistance training intensity on markers of neuroplasticity in health and disease JF - Ageing research reviews : ARR N2 - Objective: To determine the effects of low- vs. high-intensity aerobic and resistance training on motor and cognitive function, brain activation, brain structure, and neurochemical markers of neuroplasticity and the association thereof in healthy young and older adults and in patients with multiple sclerosis, Parkinson's disease, and stroke. Design: Systematic review and robust variance estimation meta-analysis with meta-regression. Data sources: Systematic search of MEDLINE, Web of Science, and CINAHL databases. Results: Fifty studies with 60 intervention arms and 2283 in-analyses participants were included. Due to the low number of studies, the three patient groups were combined and analyzed as a single group. Overall, low- (g=0.19, p = 0.024) and high-intensity exercise (g=0.40, p = 0.001) improved neuroplasticity. Exercise intensity scaled with neuroplasticity only in healthy young adults but not in healthy older adults or patient groups. Exercise-induced improvements in neuroplasticity were associated with changes in motor but not cognitive outcomes. Conclusion: Exercise intensity is an important variable to dose and individualize the exercise stimulus for healthy young individuals but not necessarily for healthy older adults and neurological patients. This conclusion warrants caution because studies are needed that directly compare the effects of low- vs. high-intensity exercise on neuroplasticity to determine if such changes are mechanistically and incrementally linked to improved cognition and motor function. KW - Aging KW - Exercise KW - Intensity Dose -response relationship KW - Cognition motor KW - function Y1 - 2022 U6 - https://doi.org/10.1016/j.arr.2022.101698 SN - 1568-1637 SN - 1872-9649 VL - 80 PB - Elsevier CY - Clare ER - TY - JOUR A1 - Ahmadi, Hamid A1 - Herat, Nehara A1 - Alizadeh, Shahab A1 - Button, Duane C. A1 - Granacher, Urs A1 - Behm, David G. T1 - Effect of an inverted seated position with upper arm blood flow restriction on measures of elbow flexors neuromuscular performance JF - PLOS ONE / Public Library of Science N2 - Purpose The objective of the investigation was to determine the concomitant effects of upper arm blood flow restriction (BFR) and inversion on elbow flexors neuromuscular responses. Methods Randomly allocated, 13 volunteers performed four conditions in a within-subject design: rest (control, 1-min upright position without BFR), control (1-min upright with BFR), 1-min inverted (without BFR), and 1-min inverted with BFR. Evoked and voluntary contractile properties, before, during and after a 30-s maximum voluntary contraction (MVC) exercise intervention were examined as well as pain scale. Results Inversion induced significant pre-exercise intervention decreases in elbow flexors MVC (21.1%, Z2p = 0.48, p = 0.02) and resting evoked twitch forces (29.4%, Z2p = 0.34, p = 0.03). The 30-s MVC induced significantly greater pre- to post-test decreases in potentiated twitch force (Z2p = 0.61, p = 0.0009) during inversion (75%) than upright (65.3%) conditions. Overall, BFR decreased MVC force 4.8% (Z2p = 0.37, p = 0.05). For upright position, BFR induced 21.0% reductions in M-wave amplitude (Z2p = 0.44, p = 0.04). There were no significant differences for electromyographic activity or voluntary activation as measured with the interpolated twitch technique. For all conditions, there was a significant increase in pain scale between the 40-60 s intervals and post-30-s MVC (upright< inversion, and without BFR< BFR). Conclusion The concomitant application of inversion with elbow flexors BFR only amplified neuromuscular performance impairments to a small degree. Individuals who execute forceful contractions when inverted or with BFR should be cognizant that force output may be impaired. Y1 - 2021 U6 - https://doi.org/10.1371/journal.pone.0245311 SN - 1932-6203 VL - 16 IS - 5 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Negra, Yassine A1 - Chaabene, Helmi A1 - Fernandez-Fernandez, Jaime A1 - Sammoud, Senda A1 - Bouguezzi, Raja A1 - Prieske, Olaf A1 - Granacher, Urs T1 - Short-term plyometric Jump training improves repeated-sprint ability in prepuberal male soccer players JF - Journal of strength and conditioning research : the research journal of the NSCA N2 - This study examined the effects of a short-term (i.e., 8 weeks) combined horizontal and vertical plyometric jump training (PJT) program in combination with regular soccer-specific training as compared with soccer-specific training only on jump and change of direction (CoD) performances, speed, and repeated-sprint ability (RSA) in prepuberal male soccer players. Twenty-four players were recruited and randomly assigned to either a PJT group (PJT(G); n = 13; 12.7 +/- 0.2 years) or an active control group (CONG; n = 11; 12.7 +/- 0.2 years). The outcome measures included tests for the assessment of jump performance (drop jump from 20- to 40-cm height [DJ20 and DJ40] and 3-hop test [THT]), speed (20-m sprint), CoD (T-test), and RSA (20-m repeated shuttle sprint). Data were analyzed using magnitude-based inferences. Within-group analyses revealed large performance improvements in the T-test (d = -1.2), DJ20 (d = 3.7), DJ40 (d = 3.6), THT (d = 0.6), and the RSA(total) (d = -1.6) in the PJT(G). Between-group analyses showed greater performance improvements in the T-test (d = -2.9), 20-m sprint time (d = -2.0), DJ20 (d = 2.4), DJ40 (d = 2.0), THT (d = 1.9), RSA(best) (d = -1.9), and the RSA(total) (d = -1.9) in the PJT(G) compared with CONG. Eight weeks of an in-season PJT in addition to regular soccer-specific training induced larger increases in measures of physical fitness in prepuberal male soccer players compared with regular soccer-specific training only. More specifically, PJT was effective in improving RSA performance. KW - youth KW - stretch-shortening cycle KW - athletic performance KW - soccer Y1 - 2020 U6 - https://doi.org/10.1519/JSC.0000000000002703 SN - 1064-8011 SN - 1533-4287 VL - 34 IS - 11 SP - 3241 EP - 3249 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Singh, Gaurav A1 - Kushwah, Gaurav Singh A1 - Singh, Tanvi A1 - Thapa, Rohit Kumar A1 - Granacher, Urs A1 - Ramirez-Campillo, Rodrigo T1 - Effects of sand-based plyometric-jump training in combination with endurance running on outdoor or treadmill surface on physical fitness in young adult males JF - Journal of sports science & medicine N2 - This study aimed at examining the effects of nine weeks of sand-based plyometric jump training (PJT) combined with endurance running on either outdoor or treadmill surface on measures of physical fitness. Male participants (age, 20.1 +/- 1.7 years) were randomly assigned to a sand-based PJT combined with endurance running on outdoor surface (OT, n = 25) or treadmill surface (TT, n = 25). The endurance miming intervention comprised a mixed training method, i.e., long slow distance, tempo, and interval running drills. A control group was additionally included in this study (CG, n = 25). Participants in CG followed their regular physical activity as OT and TT but did not receive any specific intervention. Individuals were assessed for their 50-m linear sprint time, standing long jump (SLJ) distance, cardiorespiratory fitness (i.e., Cooper test), forced vital capacity (FVC), calf girth, and resting heart rate (RHR). A three (groups: OT, TT, CG) by two (time: pre, post) ANOVA for repeated measures was used to analyze the exercise-specific effects. In case of significant group-by-time interactions, Bonferroni adjusted paired (within-group) and independent (between-group comparisons at post) t-tests were used for post-hoc analyses. Significant group-by-time interactions were found for all dependent variables (p < 0.001 - 0.002, eta(2)(p) = 0.16 - 0.78). Group-specific post-hoc tests showed improvements for all variables after OT (p < 0.001, Hedges'g effect size [g] = 0.05 - 1.94) and TT (p < 0.001, g = 0.04 - 2.73), but not in the CG (p = 0.058 - 1.000, g = 0.00 - 0.34). Compared to CG, OT showed larger SLJ (p = 0.001), cardiorespiratory fitness (p = 0.004), FVC (p = 0.008), and RHR (p < 0.001) improvements. TT showed larger improvements in SLJ (p = 0.036), cardiorespiratory fitness (p < 0.001), and RHR (p < 0.001) compared with CG. Compared to OT, TT showed larger improvements for SLJ (p = 0.018). In conclusion, sand-based PJT combined with either OT or TT similarly improved most measures of physical fitness, with greater SLJ improvement after TT. Coaches may use both concurrent exercise regimes based on preferences and logistical constrains (e.g., weather; access to treadmill equipment). KW - Muscle strength KW - musculoskeletal and neural physiological phenomena KW - movement KW - resistance training KW - high-intensity interval training KW - exercise Y1 - 2022 U6 - https://doi.org/10.52082/jssm.2022.277 SN - 1303-2968 VL - 21 IS - 2 SP - 277 EP - 286 PB - Department of Sports Medicine, Medical Faculty of Uludag University CY - Bursa ER - TY - JOUR A1 - Prieske, Olaf A1 - Chaabene, Helmi A1 - Kullmann, Niclas A1 - Granacher, Urs T1 - Effects of Individualized Versus Traditional Power Training on Strength, Power, Jump Performances, and Body Composition in Young Male Nordic Athletes JF - International journal of sports physiology and performance N2 - Purpose: This study aimed to examine the effects of individualized-load power training (IPT) versus traditional moderate-load power training (TPT) on strength, power, jump performance, and body composition in elite young Nordic athletes. Methods: In a randomized crossover design, 10 young male athletes (ski jumpers, Nordic combined athletes) age 17.5 (0.6) years (biological maturity status: +3.5 y postpeak height velocity) who competed on a national or international level performed 5 weeks of IPT (4 x 5 repetitions at 49%-72% 1-repetiton maximum [RM]) and TPT (5 x 5 repetitions at 50%-60% 1-RM) in addition to their regular training. Testing before, between, and after both training blocks comprised the assessment of muscle strength (loaded back squat 3-RM), power (maximal loaded back squat power), jump performance (eg, drop-jump height, reactive strength index), and body composition (eg, skeletal muscle mass). Results: Significant, large-size main effects for time were found for muscle strength (P < .01; g = 2.7), reactive strength index (P = .03; g= 1.6), and drop jump height (P = .02; g= 1.9) irrespective of the training condition (IPT, TPT). No significant time-by-condition interactions were observed. For measures of body composition, no significant main effects of condition and time or time-by-condition interactions were found. Conclusions: Our findings demonstrate that short-term IPT and TPT at moderate loads in addition to regular training were equally effective in improving measures of muscle strength (loaded back squat 3-RM) and vertical jump performance (reactive strength index, drop jump, and height) in young Nordic athletes. KW - ballistic training KW - optimal load KW - monitoring KW - progression KW - ski jumping Y1 - 2022 U6 - https://doi.org/10.1123/ijspp.2021-0074 SN - 1555-0265 SN - 1555-0273 VL - 17 IS - 4 SP - 541 EP - 548 PB - Human Kinetics Publ. CY - Champaign ER - TY - JOUR A1 - Jafarnezhadgero, Amir Ali A1 - Piran Hamlabadi, Milad A1 - Sajedi, Heidar A1 - Granacher, Urs T1 - Recreational runners who recovered from COVID-19 show different running kinetics and muscle activities compared with healthy controls JF - Gait & posture : official journal of Gait and Clinical Movement Analysis Society, European Society of Movement Analysis in Adults and Children, Società Italiana di Analisi del Movimento in Clinica, International Society for Posture and Gait Research N2 - Background: Social isolation through quarantine represents an effective means to prevent COVID-19 infection. A negative side-effect of quarantine is low physical activity. Research question: What are the differences of running kinetics and muscle activities of recreational runners with a history of COVID-19 versus healthy controls? Methods: Forty men and women aged 20-30 years participated in this study and were divided into two experimental groups. Group 1 (age: 24.1 +/- 2.9) consisted of participants with a history of COVID-19 (COVID group) and group 2 (age: 24.2 +/- 2.7) of healthy age and sex-matched controls (controls). Both groups were tested for their running kinetics using a force plate and electromyographic activities (i.e., tibialis anterior [TA], gastrocnemius medialis [Gas-M], biceps femoris [BF], semitendinosus [ST], vastus lateralis [VL], vastus medialis [VM], rectus femoris [RF], gluteus medius [Glut-M]). Results: Results demonstrated higher peak vertical (p = 0.029; d=0.788) and medial (p = 0.004; d=1.119) ground reaction forces (GRFs) during push-off in COVID individuals compared with controls. Moreover, higher peak lateral GRFs were found during heel contact (p = 0.001; d=1.536) in the COVID group. COVID-19 individuals showed a shorter time-to-reach the peak vertical (p = 0.001; d=3.779) and posterior GRFs (p = 0.005; d=1.099) during heel contact. Moreover, the COVID group showed higher Gas-M (p = 0.007; d=1.109) and lower VM activity (p = 0.026; d=0.811) at heel contact. Significance: Different running kinetics and muscle activities were found in COVID-19 individuals versus healthy controls. Therefore, practitioners and therapists are advised to implement balance and/or strength training to improve lower limbs alignment and mediolateral control during dynamic movements in runners who recovered from COVID-19. KW - Quarantine KW - Ground reaction force KW - Electromyography Y1 - 2022 U6 - https://doi.org/10.1016/j.gaitpost.2021.11.002 SN - 0966-6362 SN - 1879-2219 VL - 91 SP - 260 EP - 265 PB - Elsevier CY - Amsterdam [u.a.] ER -