@article{PrieskeMuehlbauerMuelleretal.2013, author = {Prieske, Olaf and M{\"u}hlbauer, Thomas and M{\"u}ller, Steffen and Kr{\"u}ger, Tom and Kibele, Armin and Behm, David George and Granacher, Urs}, title = {Effects of surface instability on neuromuscular performance during drop jumps and landings}, series = {European journal of applied physiology}, volume = {113}, journal = {European journal of applied physiology}, number = {12}, publisher = {Springer}, address = {New York}, issn = {1439-6319}, doi = {10.1007/s00421-013-2724-6}, pages = {2943 -- 2951}, year = {2013}, abstract = {The purpose of this study was to investigate the effects of surface instability on measures of performance and activity of leg and trunk muscles during drop jumps and landings. Drop jumps and landings were assessed on a force plate under stable and unstable (balance pad on top of the force plate) conditions. Performance measures (contact time, jump height, peak ground reaction force) and electromyographic (EMG) activity of leg and trunk muscles were tested in 27 subjects (age 23 +/- A 3 years) during different time intervals (preactivation phase, braking phase, push-off phase). The performance of drop jumps under unstable compared to stable conditions produced a decrease in jump height (9 \%, p < 0.001, f = 0.92) and an increase in peak ground reaction force (5 \%, p = 0.022, f = 0.72), and time for braking phase (12 \%, p < 0.001, f = 1.25). When performing drop jumps on unstable compared to stable surfaces, muscle activity was reduced in the lower extremities during the preactivation, braking and push-off phases (11-25 \%, p < 0.05, 0.48 a parts per thousand currency sign f a parts per thousand currency sign 1.23). Additionally, when landing on unstable compared to stable conditions, reduced lower limb muscle activities were observed during the preactivation phase (7-60 \%, p < 0.05, 0.50 a parts per thousand currency sign f a parts per thousand currency sign 3.62). Trunk muscle activity did not significantly differ between the test conditions for both jumping and landing tasks. The present findings indicate that modified feedforward mechanisms in terms of lower leg muscle activities during the preactivation phase and/or possible alterations in leg muscle activity shortly after ground contact (i.e., braking phase) are responsible for performance decrements during jumping on unstable surfaces.}, language = {en} } @article{PrieskeWickGranacher2014, author = {Prieske, Olaf and Wick, Ditmar and Granacher, Urs}, title = {Intrasession and intersession reliability in maximal and explosive isometric torque production of the elbow flexors}, series = {Journal of strength and conditioning research : the research journal of the NSCA}, volume = {28}, journal = {Journal of strength and conditioning research : the research journal of the NSCA}, number = {6}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1064-8011}, pages = {1771 -- 1777}, year = {2014}, abstract = {The purpose of this study was to assess intrasession and intersession reliability of maximal and explosive isometric torque production of the elbow flexors and its respective neuromuscular activation pattern. Subjects (13 men, age: 24.8 +/- 3.1 years, height: 1.9 +/- 0.1 m, body mass: 83.7 +/- 12.7 kg; and 6 women, age: 26.5 +/- 1.4 years, height: 1.7 +/- 0.1 m, body mass: 62.7 +/- 7.0 kg) were tested and retested 2-7 days later performing unilateral maximal isometric elbow flexions. Absolute (coefficient of variation[CV], test-retest variability[TRV], Bland-Altman plots with 95\% limits of agreement) and relative reliability statistics (intraclass correlation coefficient) were calculated for various mechanical (i.e., maximal isometric torque, rate of torque development, impulse) and electromyographical measures (i.e., mean average voltage) at different time intervals relative to onset of torque (i. e., 30, 50, 100, 200, 300, 400, 100-200 ms). Intraclass correlation coefficient values were >= 0.61 for all mechanical and electromyographical measures and time intervals indicating good to excellent intrasession and intersession reliability. BlandAltman plots confirmed these findings by showing that only 0-2 (<= 3.3\%) data points were beyond the limits of agreement. Regarding torque and electromyographic measures, CV (11.9-32.3\%) and TRV (18.4-53.8\%) values were high during the early intervals of torque development (<= 100 ms) indicating high variability. During the later intervals (>100 ms), lower CV (i. e., 5.0-29.9\%) and TRV values (i.e., 5.4-34.6\%) were observed indicating lower variability. The present study revealed that neuromuscular performance during explosive torque production of the elbow flexors is reproducible in time intervals >100 ms after onset of isometric actions, whereas during earlier time intervals variability is high.}, language = {en} } @article{GranacherSchellbachKleinetal.2014, 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}, series = {BMC sports science, medicine \& rehabilitation}, volume = {6}, journal = {BMC sports science, medicine \& rehabilitation}, publisher = {BioMed Central}, address = {London}, issn = {2052-1847}, doi = {10.1186/2052-1847-6-40}, pages = {11}, year = {2014}, 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} } @article{PrieskeMuehlbauerKruegeretal.2015, author = {Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Kibele, A. and Behm, David George and Granacher, Urs}, title = {Sex-Specific effects of surface instability on drop jump and landing biomechanics}, series = {International journal of sports medicine}, volume = {36}, journal = {International journal of sports medicine}, number = {1}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0034-1384549}, pages = {75 -- 81}, year = {2015}, abstract = {This study investigated sex-specific effects of surface instability on kinetics and lower extremity kinematics during drop jumping and landing. Ground reaction forces as well as knee valgus and flexion angles were tested in 14 males (age: 23 +/- 2 years) and 14 females (age: 24 +/- 3 years) when jumping and landing on stable and unstable surfaces. Jump height was found to be significantly lower (9 \%, p < 0.001) when drop jumps were performed on unstable vs. stable surface. Significantly higher peak ground reaction forces were observed when jumping was performed on unstable vs. stable surfaces (5 \%, p = 0.022). Regarding frontal plane kinematics during jumping and landing, knee valgus angles were higher on unstable compared to stable surfaces (1932 \%, p < 0.05). Additionally, at the onset of ground contact during landings, females showed higher knee valgus angles than males (222 \%, p = 0.027). Sagittal plane kinematics indicated significantly smaller knee flexion angles (6-35 \%, p < 0.05) when jumping and landing on unstable vs. stable surfaces. During drop jumps and landings, women showed smaller knee flexion angles at ground contact compared to men (27-33 \%, p < 0.05). These findings imply that knee motion strategies were modified by surface instability and sex during drop jumps and landings.}, language = {en} } @article{GranacherPrieskeMajewskietal.2015, author = {Granacher, Urs and Prieske, Olaf and Majewski, M. and B{\"u}sch, Dirk and M{\"u}hlbauer, Thomas}, title = {The Role of Instability with Plyometric Training in Sub-elite Adolescent Soccer Players}, series = {International journal of sports medicine}, volume = {36}, journal = {International journal of sports medicine}, number = {5}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0034-1395519}, pages = {386 -- 394}, year = {2015}, abstract = {The purpose of this study was to investigate the effects of plyometric training on stable (SPT) vs. highly unstable surfaces (IPT) on athletic performance in adolescent soccer players. 24 male sub-elite soccer players (age: 15 +/- 1 years) were assigned to 2 groups performing plyometric training for 8 weeks (2 sessions/week, 90min each). The SPT group conducted plyometrics on stable and the IPT group on unstable surfaces. Tests included jump performance (countermovement jump [CMJ] height, drop jump [DJ] height, DJ performance index), sprint time, agility and balance. Statistical analysis revealed significant main effects of time for CMJ height (p<0.01, f=1.44), DJ height (p<0.01, f=0.62), DJ performance index (p<0.05, f=0.60), 0-10-m sprint time (p<0.05, f=0.58), agility (p<0.01, f=1.15) and balance (p<0.05, 0.46f1.36). Additionally, a Training groupxTime interaction was found for CMJ height (p<0.01, f=0.66) in favor of the SPT group. Following 8 weeks of training, similar improvements in speed, agility and balance were observed in the IPT and SPT groups. However, the performance of IPT appears to be less effective for increasing CMJ height compared to SPT. It is thus recommended that coaches use SPT if the goal is to improve jump performance.}, language = {en} } @article{PrieskeMuehlbauerKruegeretal.2015, author = {Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Kibele, Armin and Behm, David George and Granacher, Urs}, title = {Role of the trunk during drop jumps on stable and unstable surfaces}, series = {European journal of applied physiology}, volume = {115}, journal = {European journal of applied physiology}, number = {1}, publisher = {Springer}, address = {New York}, issn = {1439-6319}, doi = {10.1007/s00421-014-3004-9}, pages = {139 -- 146}, year = {2015}, abstract = {The present study investigated associations between trunk muscle strength, jump performance, and lower limb kinematics during drop jumps on stable and unstable surfaces. Next to this behavioral approach, correlations were also computed on a neuromuscular level between trunk and leg muscle activity during the same test conditions. Twenty-nine healthy and physically active subjects (age 23 +/- A 3 years) were enrolled in this study. Peak isokinetic torque (PIT) of the trunk flexors and extensors was assessed separately on an isokinetic device. In addition, tests included drop jumps (DJ) on a force plate under stable and unstable (i.e., balance pad on top of the force plate) surfaces. Lower limb kinematics as well as electromyographic activity of selected trunk and leg muscles were analyzed. Significant positive but small correlations (0.50 a parts per thousand currency sign r a parts per thousand currency sign 0.66, p < 0.05) were detected between trunk extensor PIT and athletic performance measures (i.e., DJ height, DJ performance index), irrespective of surface condition. Further, significant negative but small correlation coefficients were examined between trunk extensor PIT and knee valgus motion under stable and unstable surface conditions (-0.48 a parts per thousand currency sign r a parts per thousand currency sign -0.45, p < 0.05). In addition, significant positive but small correlations (0.45 a parts per thousand currency sign r a parts per thousand currency sign 0.68, p < 0.05) were found between trunk and leg muscle activity, irrespective of surface condition. Behavioral and neuromuscular data from this study indicate that, irrespective of the surface condition (i.e., jumping on stable or unstable ground), the trunk plays a minor role for leg muscle performance/activity during DJ. This implies only limited effects of trunk muscle strengthening on jump performance in the stretch-shortening cycle.}, language = {en} } @misc{GranacherLesinskiBueschetal.2016, author = {Granacher, Urs and Lesinski, Melanie and Buesch, Dirk and M{\"u}hlbauer, Thomas and Prieske, Olaf and Puta, Christian and Gollhofer, Albert and Behm, David George}, title = {Effects of Resistance Training in Youth Athletes on Muscular Fitness and Athletic Performance: A Conceptual Model for Long-Term Athlete Development}, series = {Frontiers in physiology}, volume = {7}, journal = {Frontiers in physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2016.00164}, pages = {14}, year = {2016}, abstract = {During the stages of long-term athlete development (LTAD), resistance training (RT) is an important means for (i) stimulating athletic development, (ii) tolerating the demands of long-term training and competition, and (iii) inducing long-term health promoting effects that are robust over time and track into adulthood. However, there is a gap in the literature with regards to optimal RT methods during LTAD and how RT is linked to biological age. Thus, the aims of this scoping review were (i) to describe and discuss the effects of RT on muscular fitness and athletic performance in youth athletes, (ii) to introduce a conceptual model on how to appropriately implement different types of RT within LTAD stages, and (iii) to identify research gaps from the existing literature by deducing implications for future research. In general, RT produced small -to -moderate effects on muscular fitness and athletic performance in youth athletes with muscular strength showing the largest improvement. Free weight, complex, and plyometric training appear to be well -suited to improve muscular fitness and athletic performance. In addition, balance training appears to be an important preparatory (facilitating) training program during all stages of LTAD but particularly during the early stages. As youth athletes become more mature, specificity, and intensity of RT methods increase. This scoping review identified research gaps that are summarized in the following and that should be addressed in future studies: (i) to elucidate the influence of gender and biological age on the adaptive potential following RT in youth athletes (especially in females), (ii) to describe RT protocols in more detail (i.e., always report stress and strain based parameters), and (iii) to examine neuromuscular and tendomuscular adaptations following RT in youth athletes.}, 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{LesinskiPrieskeGranacher2016, author = {Lesinski, Melanie and Prieske, Olaf and Granacher, Urs}, title = {Effects and dose-response relationships of resistance training on physical performance in youth athletes: a systematic review and meta-analysis}, series = {British journal of sports medicine : the journal of sport and exercise medicine}, volume = {50}, journal = {British journal of sports medicine : the journal of sport and exercise medicine}, publisher = {BMJ Publishing Group}, address = {London}, issn = {0306-3674}, doi = {10.1136/bjsports-2015-095497}, pages = {781 -- 795}, year = {2016}, abstract = {Objectives To quantify age, sex, sport and training type-specific effects of resistance training on physical performance, and to characterise dose-response relationships of resistance training parameters that could maximise gains in physical performance in youth athletes. Design Systematic review and meta-analysis of intervention studies. Data sources Studies were identified by systematic literature search in the databases PubMed and Web of Science (1985-2015). Weighted mean standardised mean differences (SMDwm) were calculated using random-effects models. Eligibility criteria for selecting studies Only studies with an active control group were included if these investigated the effects of resistance training in youth athletes (6-18 years) and tested at least one physical performance measure. Results 43 studies met the inclusion criteria. Our analyses revealed moderate effects of resistance training on muscle strength and vertical jump performance (SMDwm 0.8-1.09), and small effects on linear sprint, agility and sport-specific performance (SMDwm 0.58-0.75). Effects were moderated by sex and resistance training type. Independently computed dose-response relationships for resistance training parameters revealed that a training period of >23 weeks, 5 sets/exercise, 6-8 repetitions/set, a training intensity of 80-89\% of 1 repetition maximum (RM), and 3-4 min rest between sets were most effective to improve muscle strength (SMDwm 2.09-3.40). Summary/conclusions Resistance training is an effective method to enhance muscle strength and jump performance in youth athletes, moderated by sex and resistance training type. Dose-response relationships for key training parameters indicate that youth coaches should primarily implement resistance training programmes with fewer repetitions and higher intensities to improve physical performance measures of youth athletes.}, language = {en} } @article{PrieskeMuehlbauerBordeetal.2016, author = {Prieske, Olaf and M{\"u}hlbauer, Thomas and Borde, Ron and Gube, M. and Bruhn, S. and Behm, David George and Granacher, Urs}, title = {Neuromuscular and athletic performance following core strength training in elite youth soccer: Role of instability}, series = {Learning and individual differences}, volume = {26}, journal = {Learning and individual differences}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0905-7188}, doi = {10.1111/sms.12403}, pages = {48 -- 56}, year = {2016}, abstract = {Cross-sectional studies revealed that inclusion of unstable elements in core-strengthening exercises produced increases in trunk muscle activity and thus potential extra stimuli to induce more pronounced performance enhancements in youth athletes. Thus, the purpose of the study was to investigate changes in neuromuscular and athletic performance following core strength training performed on unstable (CSTU) compared with stable surfaces (CSTS) in youth soccer players. Thirty-nine male elite soccer players (age: 17 +/- 1 years) were assigned to two groups performing a progressive core strength-training program for 9 weeks (2-3 times/week) in addition to regular in-season soccer training. CSTS group conducted core exercises on stable (i.e., floor, bench) and CSTU group on unstable (e.g., Thera-Band (R) Stability Trainer, Togu (c) Swiss ball) surfaces. Measurements included tests for assessing trunk muscle strength/activation, countermovement jump height, sprint time, agility time, and kicking performance. Statistical analysis revealed significant main effects of test (pre vs post) for trunk extensor strength (5\%, P<0.05, d=0.86), 10-20-m sprint time (3\%, P<0.05, d=2.56), and kicking performance (1\%, P<0.01, d=1.28). No significant Groupxtest interactions were observed for any variable. In conclusion, trunk muscle strength, sprint, and kicking performance improved following CSTU and CSTS when conducted in combination with regular soccer training.}, language = {en} } @misc{PrieskeMuehlbauerGranacher2016, author = {Prieske, Olaf and M{\"u}hlbauer, Thomas and Granacher, Urs}, title = {The Role of Trunk Muscle Strength for Physical Fitness and Athletic Performance in Trained Individuals: A Systematic Review and Meta-Analysis}, series = {Sports medicine}, volume = {46}, journal = {Sports medicine}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-015-0426-4}, pages = {401 -- 419}, year = {2016}, abstract = {Background The importance of trunk muscle strength (TMS) for physical fitness and athletic performance has been demonstrated by studies reporting significant correlations between those capacities. However, evidence-based knowledge regarding the magnitude of correlations between TMS and proxies of physical fitness and athletic performance as well as potential effects of core strength training (CST) on TMS, physical fitness and athletic performance variables is currently lacking for trained individuals. Objective The aims of this systematic review and meta-analysis were to quantify associations between variables of TMS, physical fitness and athletic performance and effects of CST on these measures in healthy trained individuals. Data Sources PubMed, Web of Science, and SPORTDiscus were systematically screened from January 1984 to March 2015. Study Eligibility Criteria Studies were included that investigated healthy trained individuals aged 16-44 years and tested at least one measure of TMS, muscle strength, muscle power, balance, and/or athletic performance. Results Small-sized relationships of TMS with physical performance measures (-0.05 <= r <= 0.18) were found in 15 correlation studies. Sixteen intervention studies revealed large effects of CST on measures of TMS (SMD = 1.07) but small-to-medium-sized effects on proxies of physical performance (0 <= SMD <= 0.71) compared with no training or regular training only. The methodological quality of CST studies was low (median PEDro score = 4). Conclusions Our findings indicate that TMS plays only a minor role for physical fitness and athletic performance in trained individuals. In fact, CST appears to be an effective means to increase TMS and was associated with only limited gains in physical fitness and athletic performance measures when compared with no or only regular training.}, language = {en} } @article{LesinskiPrieskeDempsetal.2016, author = {Lesinski, Melanie and Prieske, Olaf and Demps, Marie and Granacher, Urs}, title = {Effects of fatigue and surface instability on neuromuscular performance during jumping}, series = {Der Schmerz : Organ der Deutschen Gesellschaft zum Studium des Schmerzes, der {\~A}-sterreichischen Schmerzgesellschaft und der Deutschen Interdisziplin{\~A}\iren Vereinigung f{\~A}¼r Schmerztherapie}, volume = {26}, journal = {Der Schmerz : Organ der Deutschen Gesellschaft zum Studium des Schmerzes, der {\~A}-sterreichischen Schmerzgesellschaft und der Deutschen Interdisziplin{\~A}\iren Vereinigung f{\~A}¼r Schmerztherapie}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0905-7188}, doi = {10.1111/sms.12548}, pages = {1140 -- 1150}, year = {2016}, abstract = {It has previously been shown that fatigue and unstable surfaces affect jump performance. However, the combination thereof is unresolved. Thus, the purpose of this study was to examine the effects of fatigue and surface instability on jump performance and leg muscle activity. Twenty elite volleyball players (18 +/- 2 years) performed repetitive vertical double-leg box jumps until failure. Before and after a fatigue protocol, jump performance (i.e., jump height) and electromyographic activity of selected lower limb muscles were recorded during drop jumps (DJs) and countermovement jumps (CMJs) on a force plate on stable and unstable surfaces (i.e., balance pad on top of force plate). Jump performance (3-7\%; P < 0.05; 1.14 <= d <= 2.82), and muscle activity (2-27\%; P < 0.05; 0.59 <= d <= 3.13) were lower following fatigue during DJs and CMJs, and on unstable compared with stable surfaces during DJs only (jump performance: 8\%; P < 0.01; d = 1.90; muscle activity: 9-25\%; P < 0.05; 1.08 <= d <= 2.54). No statistically significant interactions of fatigue by surface condition were observed. Our findings revealed that fatigue impairs neuromuscular performance during DJs and CMJs in elite volleyball players, whereas surface instability affects neuromuscular DJ performance only. Absent fatigue x surface interactions indicate that fatigue-induced changes in jump performance are similar on stable and unstable surfaces in jump-trained athletes.}, language = {en} } @misc{GranacherLesinskiBueschetal.2016, author = {Granacher, Urs and Lesinski, Melanie and B{\"u}sch, Dirk and M{\"u}hlbauer, Thomas and Prieske, Olaf and Puta, Christian and Gollhofer, Albert and Behm, David George}, title = {Effects of resistance training in youth athletes on muscular fitness and athletic performance}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {429}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-406574}, pages = {14}, year = {2016}, abstract = {During the stages of long-term athlete development (LTAD), resistance training (RT) is an important means for (i) stimulating athletic development, (ii) tolerating the demands of long-term training and competition, and (iii) inducing long-term health promoting effects that are robust over time and track into adulthood. However, there is a gap in the literature with regards to optimal RT methods during LTAD and how RT is linked to biological age. Thus, the aims of this scoping review were (i) to describe and discuss the effects of RT on muscular fitness and athletic performance in youth athletes, (ii) to introduce a conceptual model on how to appropriately implement different types of RT within LTAD stages, and (iii) to identify research gaps from the existing literature by deducing implications for future research. In general, RT produced small -to -moderate effects on muscular fitness and athletic performance in youth athletes with muscular strength showing the largest improvement. Free weight, complex, and plyometric training appear to be well -suited to improve muscular fitness and athletic performance. In addition, balance training appears to be an important preparatory (facilitating) training program during all stages of LTAD but particularly during the early stages. As youth athletes become more mature, specificity, and intensity of RT methods increase. This scoping review identified research gaps that are summarized in the following and that should be addressed in future studies: (i) to elucidate the influence of gender and biological age on the adaptive potential following RT in youth athletes (especially in females), (ii) to describe RT protocols in more detail (i.e., always report stress and strain based parameters), and (iii) to examine neuromuscular and tendomuscular adaptations following RT in youth athletes.}, language = {en} } @article{KuemmelBergmannPrieskeetal.2016, author = {Kuemmel, 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: a randomized crossover pilot study in elite athletes}, series = {BMC sports science, medicine \& rehabilitation}, volume = {8}, journal = {BMC sports science, medicine \& rehabilitation}, publisher = {BioMed Central}, address = {London}, issn = {2052-1847}, doi = {10.1186/s13102-016-0027-z}, pages = {8}, year = {2016}, 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} } @article{LesinskiPrieskeHelmetal.2017, author = {Lesinski, Melanie and Prieske, Olaf and Helm, Norman and Granacher, Urs}, title = {Effects of Soccer Training on Anthropometry, Body Composition, and Physical Fitness during a Soccer Season in Female Elite Young Athletes: A Prospective Cohort Study}, series = {Frontiers in physiology}, volume = {8}, journal = {Frontiers in physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2017.01093}, pages = {13}, year = {2017}, abstract = {The objectives of this study were to (i) describe soccer training (e.g., volume, types), anthropometry, body composition, and physical fitness and (0 compute associations between soccer training data and relative changes of anthropometry, body composition, and physical fitness during a soccer season in female elite young athletes. Seasonal training (i.e., day-to-day training volume/types) as well as variations in anthropometry (e.g., body height/mass), body composition (e.g., lean body/fat mass), and physical fitness (e.g., muscle strength/power, speed, balance) were collected from 17 female elite young soccer players (15.3 +/- 0.5 years) over the training periods (i.e., preparation, competition, transition) of a soccer season that resulted in the German championship title in under-17 female soccer. Training volume/types, anthropometrics, body composition, and physical fitness significantly varied over a soccer season. During the two preparation periods, higher volumes in resistance and endurance training were performed (2.00 <= d <= 18.15; p < 0.05), while higher sprint and tactical training volumes were applied during the two competition periods (2.22 <= d <= 11.18; p < 0.05). Body height and lean body mass increased over the season (2.50 <= d <= 3.39; p < 0.01). In terms of physical fitness, significant performance improvements were found over the soccer season in measures of balance, endurance, and sport-specific performance (2.52 <= d <= 3.95; p < 0.05). In contrast, no statistically significant changes were observed for measures of muscle power/endurance, speed, and change-of-direction speed. Of note, variables of muscle strength (i.e., leg extensors) significantly decreased (d = 2.39: p < 0.01) over the entire season. Our period specific sub analyses revealed significant performance improvements during the first round of the season for measures of muscle power/endurance, and balance (0.89 <= d <= 4.01; p < 0.05). Moreover, change-of-direction speed significantly declined after the first round of the season, i.e., transition period (d = 2.83; p < 0.01). Additionally, significant medium-to-large associations were observed between training and anthropometrics/body composition/physical fitness (-0.541 <= r <= 0.505). Soccer training and/or growth/maturation contributed to significant variations in anthropometry, body composition, and physical fitness outcomes throughout the different training periods over the course of a soccer season in female elite young soccer players. However, changes in components of fitness were inconsistent (e.g., power, speed, strength). Thus, training volume and/or types should be carefully considered in order to develop power-, speed- or strength-related fitness measures more efficiently throughout the soccer season.}, language = {en} } @article{PrieskeAboodardaSierraetal.2017, author = {Prieske, Olaf and Aboodarda, Saied J. and Sierra, Jose A. Benitez and Behm, David G. and Granacher, Urs}, title = {Slower but not faster unilateral fatiguing knee extensions alter contralateral limb performance without impairment of maximal torque output}, series = {European journal of applied physiology}, volume = {117}, journal = {European journal of applied physiology}, publisher = {Springer}, address = {New York}, issn = {1439-6319}, doi = {10.1007/s00421-016-3524-6}, pages = {323 -- 334}, year = {2017}, abstract = {The purpose of the present study was to examine the effects of unilateral fatigue of the knee extensors at different movement velocities on neuromuscular performance in the fatigued and non-fatigued leg. Unilateral fatigue of the knee extensors was induced in 11 healthy young men (23.7 +/- 3.8 years) at slower (60A degrees/s; FAT60) and faster movement velocities (240A degrees/s; FAT240) using an isokinetic dynamometer. A resting control (CON) condition was included. The fatigue protocols consisted of five sets of 15 maximal concentric knee extensions using the dominant leg. Before and after fatigue, peak isokinetic torque (PIT) and time to PIT (TTP) of the knee extensors as well as electromyographic (EMG) activity of vastus medialis, vastus lateralis, and biceps femoris muscles were assessed at 60 and 240A degrees/s movement velocities in the fatigued and non-fatigued leg. In the fatigued leg, significantly greater PIT decrements were observed following FAT60 and FAT240 (11-19\%) compared to CON (3-4\%, p = .002, d = 2.3). Further, EMG activity increased in vastus lateralis and biceps femoris muscle following FAT240 only (8-28\%, 0.018 <= p <=.024, d = 1.8). In the non-fatigued leg, shorter TTP values were found after the FAT60 protocol (11-15\%, p = .023, d = 2.4). No significant changes were found for EMG data in the non-fatigued leg. The present study revealed that both slower and faster velocity fatiguing contractions failed to show any evidence of cross-over fatigue on PIT. However, unilateral knee extensor fatigue protocols conducted at slower movement velocities (i.e., 60A degrees/s) appear to modulate torque production on the non-fatigued side (evident in shorter TTP values).}, language = {en} } @article{PrieskeDempsLesinskietal.2017, author = {Prieske, Olaf and Demps, Marie and Lesinski, Melanie and Granacher, Urs}, title = {Combined Effects of Fatigue and Surface Instability on Jump Biomechanics in Elite Athletes}, series = {International journal of sports medicine}, volume = {38}, journal = {International journal of sports medicine}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0043-111894}, pages = {781 -- 790}, year = {2017}, abstract = {The present study aimed to examine the effects of fatigue and surface instability on kinetic and kinematic jump performance measures. Ten female and 10 male elite volleyball players (18 +/- 2 years) performed repetitive vertical double-leg box jumps until failure. Pre and post fatigue, jump height/performance index, ground reaction force and knee flexion/valgus angles were assessed during drop and countermovement jumps on stable and unstable surfaces. Fatigue, surface condition, and sex resulted in significantly lower drop jump performance and ground reaction force (p0.031, 1.1d3.5). Additionally, drop jump knee flexion angles were significantly lower following fatigue (p=0.006, d=1.5). A significant fatiguexsurfacexsex interaction (p=0.020, d=1.2) revealed fatigue-related decrements in drop jump peak knee flexion angles under unstable conditions and in men only. Knee valgus angles were higher on unstable compared to stable surfaces during drop jumps and in females compared to males during drop and countermovement jumps (p0.054, 1.0d1.1). Significant surfacexsex interactions during countermovement jumps (p=0.002, d=1.9) indicated that knee valgus angles at onset of ground contact were significantly lower on unstable compared to stable surfaces in males but higher in females. Our findings revealed that fatigue and surface instability resulted in sex-specific knee motion strategies during jumping in elite volleyball players.}, language = {en} } @misc{BehmYoungWhittenetal.2017, author = {Behm, David George and Young, James D. and Whitten, Joseph H. D. and Reid, Jonathan C. and Quigley, Patrick J. and Low, Jonathan and Li, Yimeng and Lima, Camila D. and Hodgson, Daniel D. and Chaouachi, Anis and Prieske, Olaf and Granacher, Urs}, title = {Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis}, series = {Frontiers in physiology}, volume = {8}, journal = {Frontiers in physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2017.00423}, pages = {37}, year = {2017}, abstract = {Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral landings and propulsions associated with sprinting. Based on this meta-analysis, strength training should be incorporated prior to power training in order to establish an adequate foundation of strength for power training activities.}, language = {en} } @article{LesinskiPrieskeBeurskensetal.2017, author = {Lesinski, Melanie and Prieske, Olaf and Beurskens, Rainer and Behm, David George and Granacher, Urs}, title = {Effects of drop height and surface instability on neuromuscular activation during drop jumps}, series = {Scandinavian journal of medicine \& science in sports}, volume = {27}, journal = {Scandinavian journal of medicine \& science in sports}, publisher = {Wiley}, address = {Hoboken}, issn = {0905-7188}, doi = {10.1111/sms.12732}, pages = {1090 -- 1098}, year = {2017}, abstract = {The purpose of this study was to examine whether drop height-induced changes in leg muscle activity during drop jumps (DJ) are additionally modulated by surface condition. Twenty-four healthy participants (23.7 +/- 1.8years) performed DJs on a force plate on stable, unstable, and highly unstable surfaces using different drop heights (i.e., 20cm, 40cm, 60cm). Electromyographic (EMG) activity of soleus (SOL), gastrocnemius (GM), tibialis anterior (TA) muscles and coactivation of TA/SOL and TA/GM were analyzed for time intervals 100ms prior to ground contact (preactivation) and 30-60ms after ground contact [short latency response (SLR)]. Increasing drop heights resulted in progressively increased SOL and GM activity during preactivation and SLR (P<0.01; 1.01 d 5.34) while TA/SOL coactivation decreased (P<0.05; 0.51 d 3.01). Increasing surface instability produced decreased activities during preactivation (GM) and SLR (GM, SOL) (P<0.05; 1.36 d 4.30). Coactivation increased during SLR (P<0.05; 1.50 d 2.58). A significant drop heightxsurface interaction was observed for SOL during SLR. Lower SOL activity was found on unstable compared to stable surfaces for drop heights 40cm (P<0.05; 1.25 d 2.12). Findings revealed that instability-related changes in activity of selected leg muscles are minimally affected by drop height.}, language = {en} } @article{LesinskiPrieskeBeurskensetal.2017, author = {Lesinski, Melanie and Prieske, Olaf and Beurskens, Rainer and Behm, David George and Granacher, Urs}, title = {Effects of Drop-height and Surface Instability on Jump Performance and Knee Kinematics}, series = {International journal of sports medicine}, volume = {39}, journal = {International journal of sports medicine}, number = {1}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0043-117610}, pages = {50 -- 57}, year = {2017}, abstract = {The purpose of this study was to examine the combined effects of drop-height and surface condition on drop jump (DJ) performance and knee joint kinematics. DJ performance, sagittal and frontal plane knee joint kinematics were measured in jump experienced young male and female adults during DJs on stable, unstable and highly unstable surfaces using different drop-heights (20, 40, 60 cm). Findings revealed impaired DJ performance (Δ5-16\%; p<0.05; 1.43≤d≤2.82), reduced knee valgus motion (Δ33-52\%; p<0.001; 2.70≤d≤3.59), and larger maximum knee flexion angles (Δ13-19\%; p<0.01; 1.74≤d≤1.75) when using higher (60 cm) compared to lower drop-heights (≤40 cm). Further, lower knee flexion angles and velocity were found (Δ8-16\%; p<0.01; 1.49≤d≤2.38) with increasing surface instability. When performing DJs from high (60 cm) compared to moderate drop-heights (40 cm) on highly unstable surfaces, higher knee flexion velocity and maximum knee valgus angles were found (Δ15-19\%; p<0.01; 1.50≤d≤1.53). No significant main and/or interaction effects were observed for the factor sex. In conclusion, knee motion strategies were modified by the factors 'drop-height' and/or 'surface instability'. The combination of high drop-heights (>40 cm) together with highly unstable surfaces should be used cautiously during plyometrics because this may increase the risk of injury due to higher knee valgus stress.}, 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} } @article{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 = {Sports}, volume = {6}, journal = {Sports}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2075-4663}, doi = {10.3390/sports6040119}, pages = {8}, 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} } @article{HelmPrieskeMuehlbaueretal.2018, author = {Helm, Norman and Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Chaabene, Helmi and Granacher, Urs}, title = {Validation of a new judo-specific ergometer system in male elite and sub-elite athletes}, series = {Journal of sports science \& medicine}, volume = {17}, journal = {Journal of sports science \& medicine}, number = {3}, publisher = {Department of Sports Medicine, Medical Faculty of Uludag University}, address = {Bursa}, issn = {1303-2968}, pages = {465 -- 474}, year = {2018}, abstract = {Our experimental approach included two studies to determine discriminative validity and test-retest reliability (study 1) as well as ecological validity (study 2) of a judo ergometer system while performing judo-specific movements. Sixteen elite (age: 23 +/- 3 years) and 11 sub-elite (age: 16 +/- 1 years) athletes participated in study 1 and 14 male sub-elite judo athletes participated in study 2. Discriminative validity and test-retest reliability of sport-specific parameters (mechanical work, maximal force) were assessed during pulling movements with and without tsukuri (kuzushi). Ecological validity of muscle activity was determined by performing pulling movements using the ergometer without tsukuri and during the same movements against an opponent. In both conditions, electromyographic activity of trunk (e.g., m. erector spinae) and upper limb muscles (e.g., m. biceps brachii) were assessed separately for the lifting and pulling arm. Elite athletes showed mostly better mechanical work, maximal force, and power (0.12 <= d <= 1.80) compared with sub-elite athletes. The receiver operating characteristic analysis revealed acceptable validity of the JERGo(C) system to discriminate athletes of different performance levels predominantly during kuzushi without tsukuri (area under the curve = 0.27-0.90). Moreover, small-to-medium discriminative validity was found to detect meaningful performance changes for mechanical work and maximal force. The JERGo(C) system showed small-to-high relative (ICC = 0.37-0.92) and absolute reliability (SEM = 10.8-18.8\%). Finally, our analyses revealed acceptable correlations (r = 0.41-0.88) between muscle activity during kuzushi performed with the JERGo(C) system compared with a judo opponent. Our findings indicate that the JERGo(C) system is a valid and reliable test instrument for the assessment and training of judo-specific pulling kinetics particularly during kuzushi movement without tsukuri.}, language = {en} } @article{HelmPrieskeMuehlbaueretal.2018, author = {Helm, Norman and Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Granacher, Urs}, title = {Effects of judo-specific resistance training on kinetic and electromyographic parameters of pulling exercises in judo athletes}, series = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, volume = {32}, journal = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, number = {2}, publisher = {Thieme}, address = {Stuttgart}, issn = {0932-0555}, doi = {10.1055/s-0043-122781}, pages = {134 -- 142}, year = {2018}, abstract = {Background In judo, rapid force production during pulling movements is an important component of athletic performance, which is why this capacity needs to be specifically exercised in judo. This study aimed at examining the effects of a judo-specific resistance training program using a judo ergometer system (PTJ) versus a traditional resistance training regime using a partner (PTP) on kinetics and muscle activity of judo-specific pulling exercises. Method Twenty-four male judo athletes (age: 22 +/- 4 years, training experience: 15 +/- 3 years) were randomly assigned to two groups. In a crossover design, the first group completed a 4-week PTJ followed by four weeks of PTP (each with three sessions per week). The second group conducted PTP prior to PTJ. PTJ and PTP were completed in addition to regular training. Before, 4 weeks and 8 weeks after training, tests were conducted to assess judo-specific pulling kinetics (i.e. maximal force, rate of force development [RFD], mechanical work) and electromyographic (EMG) shoulder/trunk muscle activity (i.e. biceps brachii muscle, deltoid muscle, trapezius muscle, erector spinae muscle) during pulling movements using a judo ergometer as well as unspecific strength tests (i.e. bench-pull, pull-ups). Results The statistical analysis revealed that in both groups ergometer pulling kinetics (p<.05, 0.83 <= d <= 1.77) and EMG activity (p<.05; 1.07 <= d <= 2.25) were significantly enhanced following 8 weeks of training. In addition, significantly larger gains in RFD, mechanical work, and EMG activity (i.e. deltoid muscle, erector spinae muscle, trapezius muscle) were found following PTJ compared to PTP (p<.05, 1.25 <= d <= 2.79). No significant enhancements were observed with the unspecific strength tests. Conclusion Our findings indicate that PTJ is superior to PTP regarding training-induced improvements in force production and muscle activity during judo-specific pulling exercises. Performance enhancements may partly be attributed to neural adaptations. No transfer effects on unspecific strength tests were detected following PTJ and PTP.}, language = {de} } @article{GaeblerPrieskeHortobagyietal.2018, author = {G{\"a}bler, Martijn and Prieske, Olaf and Hortobagyi, Tibor and Granacher, Urs}, title = {The Effects of Concurrent Strength and Endurance Training on Physical Fitness and Athletic Performance in Youth}, series = {Frontiers in Physiology}, volume = {9}, journal = {Frontiers in Physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2018.01057}, pages = {1 -- 13}, year = {2018}, abstract = {Combining training of muscle strength and cardiorespiratory fitness within a training cycle could increase athletic performance more than single-mode training. However, the physiological effects produced by each training modality could also interfere with each other, improving athletic performance less than single-mode training. Because anthropometric, physiological, and biomechanical differences between young and adult athletes can affect the responses to exercise training, young athletes might respond differently to concurrent training (CT) compared with adults. Thus, the aim of the present systematic review with meta-analysis was to determine the effects of concurrent strength and endurance training on selected physical fitness components and athletic performance in youth. A systematic literature search of PubMed and Web of Science identified 886 records. The studies included in the analyses examined children (girls age 6-11 years, boys age 6-13 years) or adolescents (girls age 12-18 years, boys age 14-18 years), compared CT with single-mode endurance (ET) or strength training (ST), and reported at least one strength/power—(e.g., jump height), endurance—(e.g., peak V°O2, exercise economy), or performance-related (e.g., time trial) outcome. We calculated weighted standardized mean differences (SMDs). CT compared to ET produced small effects in favor of CT on athletic performance (n = 11 studies, SMD = 0.41, p = 0.04) and trivial effects on cardiorespiratory endurance (n = 4 studies, SMD = 0.04, p = 0.86) and exercise economy (n = 5 studies, SMD = 0.16, p = 0.49) in young athletes. A sub-analysis of chronological age revealed a trend toward larger effects of CT vs. ET on athletic performance in adolescents (SMD = 0.52) compared with children (SMD = 0.17). CT compared with ST had small effects in favor of CT on muscle power (n = 4 studies, SMD = 0.23, p = 0.04). In conclusion, CT is more effective than single-mode ET or ST in improving selected measures of physical fitness and athletic performance in youth. Specifically, CT compared with ET improved athletic performance in children and particularly adolescents. Finally, CT was more effective than ST in improving muscle power in youth.}, 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} } @article{ChaabenePrieskeNegraetal.2018, author = {Chaabene, Helmi and Prieske, Olaf and Negra, Yassine and Granacher, Urs}, title = {Change of direction speed}, series = {Sports medicine}, volume = {48}, journal = {Sports medicine}, number = {8}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-018-0907-3}, pages = {1773 -- 1779}, year = {2018}, abstract = {There is growing evidence that eccentric strength training appears to have benefits over traditional strength training (i.e., strength training with combined concentric and eccentric muscle actions) from muscular, neuromuscular, tendinous, and metabolic perspectives. Eccentric muscle strength is particularly needed to decelerate and stabilize the body during the braking phase of a jump exercise or during rapid changes of direction (CoD) tasks. However, surprisingly little research has been conducted to elucidate the effects of eccentric strength training or strength training with accentuated eccentric muscle actions on CoD speed performance. In this current opinion article, we present findings from cross-sectional studies on the relationship between measures of eccentric muscle strength and CoD speed performance. In addition, we summarize the few available studies on the effects of strength training with accentuated eccentric muscle actions on CoD speed performance in athletic populations. Finally, we propose strength training with accentuated eccentric muscle actions as a promising element in strength and conditioning programs of sports with high CoD speed demands. Our findings from five cross-sectional studies revealed statistically significant moderate-to large-sized correlations (r = 0.45-0.89) between measures of eccentric muscle strength and CoD speed performance in athletic populations. The identified three intervention studies were of limited methodological quality and reported small-to large-sized effects (d = 0.46-1.31) of strength training with accentuated eccentric muscle actions on CoD speed performance in athletes. With reference to the available but preliminary literature and from a performance-related point of view, we recommend strength and conditioning coaches to include strength training with accentuated eccentric muscle actions in training routines of sports with high CoD speed demands (e.g., soccer, handball, basketball, hockey) to enhance sport-specific performance. Future comparative studies are needed to deepen our knowledge of the effects of strength training with accentuated eccentric muscle actions on CoD speed performance in athletes.}, 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} } @article{PrieskeKruegerAehleetal.2018, author = {Prieske, Olaf and Kr{\"u}ger, Tom and Aehle, Markus and Bauer, Erik and Granacher, Urs}, title = {Effects of Resisted Sprint Training and Traditional Power Training on Sprint, Jump, and Balance Performance in Healthy Young Adults}, series = {Frontiers in Physiology}, volume = {9}, journal = {Frontiers in Physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2018.00156}, pages = {1 -- 10}, year = {2018}, abstract = {Power training programs have proved to be effective in improving components of physical fitness such as speed. According to the concept of training specificity, it was postulated that exercises must attempt to closely mimic the demands of the respective activity. When transferring this idea to speed development, the purpose of the present study was to examine the effects of resisted sprint (RST) vs. traditional power training (TPT) on physical fitness in healthy young adults. Thirty-five healthy, physically active adults were randomly assigned to a RST (n = 10, 23 ± 3 years), a TPT (n = 9, 23 ± 3 years), or a passive control group (n = 16, 23 ± 2 years). RST and TPT exercised for 6 weeks with three training sessions/week each lasting 45-60 min. RST comprised frontal and lateral sprint exercises using an expander system with increasing levels of resistance that was attached to a treadmill (h/p/cosmos). TPT included ballistic strength training at 40\% of the one-repetition-maximum for the lower limbs (e.g., leg press, knee extensions). Before and after training, sprint (20-m sprint), change-of-direction speed (T-agility test), jump (drop, countermovement jump), and balance performances (Y balance test) were assessed. ANCOVA statistics revealed large main effects of group for 20-m sprint velocity and ground contact time (0.81 ≤ d ≤ 1.00). Post-hoc tests showed higher sprint velocity following RST and TPT (0.69 ≤ d ≤ 0.82) when compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to 4.5\% for RST [90\%CI: (-1.1\%;10.1\%), d = 1.23] and 2.6\% for TPT [90\%CI: (0.4\%;4.8\%), d = 1.59]. Additionally, ground contact times during sprinting were shorter following RST and TPT (0.68 ≤ d ≤ 1.09) compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to -6.3\% for RST [90\%CI: (-11.4\%;-1.1\%), d = 1.45) and -2.7\% for TPT [90\%CI: (-4.2\%;-1.2\%), d = 2.36]. Finally, effects for change-of-direction speed, jump, and balance performance varied from small-to-large. The present findings indicate that 6 weeks of RST and TPT produced similar effects on 20-m sprint performance compared with a passive control in healthy and physically active, young adults. However, no training-related effects were found for change-of-direction speed, jump and balance performance. We conclude that both training regimes can be applied for speed development.}, language = {en} } @article{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 = {Frontiers in Physiology}, volume = {9}, journal = {Frontiers in Physiology}, publisher = {Frontiers}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2018.00276}, pages = {1 -- 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{GaeblerPrieskeHortobagyietal.2018, author = {G{\"a}bler, Martijn and Prieske, Olaf and Hortobagyi, Tibor and Granacher, Urs}, title = {The Effects of Concurrent Strength and Endurance Training on Physical Fitness and Athletic Performance in Youth}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {471}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417683}, pages = {13}, year = {2018}, abstract = {Combining training of muscle strength and cardiorespiratory fitness within a training cycle could increase athletic performance more than single-mode training. However, the physiological effects produced by each training modality could also interfere with each other, improving athletic performance less than single-mode training. Because anthropometric, physiological, and biomechanical differences between young and adult athletes can affect the responses to exercise training, young athletes might respond differently to concurrent training (CT) compared with adults. Thus, the aim of the present systematic review with meta-analysis was to determine the effects of concurrent strength and endurance training on selected physical fitness components and athletic performance in youth. A systematic literature search of PubMed and Web of Science identified 886 records. The studies included in the analyses examined children (girls age 6-11 years, boys age 6-13 years) or adolescents (girls age 12-18 years, boys age 14-18 years), compared CT with single-mode endurance (ET) or strength training (ST), and reported at least one strength/power—(e.g., jump height), endurance—(e.g., peak V°O2, exercise economy), or performance-related (e.g., time trial) outcome. We calculated weighted standardized mean differences (SMDs). CT compared to ET produced small effects in favor of CT on athletic performance (n = 11 studies, SMD = 0.41, p = 0.04) and trivial effects on cardiorespiratory endurance (n = 4 studies, SMD = 0.04, p = 0.86) and exercise economy (n = 5 studies, SMD = 0.16, p = 0.49) in young athletes. A sub-analysis of chronological age revealed a trend toward larger effects of CT vs. ET on athletic performance in adolescents (SMD = 0.52) compared with children (SMD = 0.17). CT compared with ST had small effects in favor of CT on muscle power (n = 4 studies, SMD = 0.23, p = 0.04). In conclusion, CT is more effective than single-mode ET or ST in improving selected measures of physical fitness and athletic performance in youth. Specifically, CT compared with ET improved athletic performance in children and particularly adolescents. Finally, CT was more effective than ST in improving muscle power in youth.}, language = {en} } @misc{PrieskeKruegerAehleetal.2018, author = {Prieske, Olaf and Kr{\"u}ger, Tom and Aehle, Markus and Bauer, Erik and Granacher, Urs}, title = {Effects of Resisted Sprint Training and Traditional Power Training on Sprint, Jump, and Balance Performance in Healthy Young Adults}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {383}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409645}, pages = {10}, year = {2018}, abstract = {Power training programs have proved to be effective in improving components of physical fitness such as speed. According to the concept of training specificity, it was postulated that exercises must attempt to closely mimic the demands of the respective activity. When transferring this idea to speed development, the purpose of the present study was to examine the effects of resisted sprint (RST) vs. traditional power training (TPT) on physical fitness in healthy young adults. Thirty-five healthy, physically active adults were randomly assigned to a RST (n = 10, 23 ± 3 years), a TPT (n = 9, 23 ± 3 years), or a passive control group (n = 16, 23 ± 2 years). RST and TPT exercised for 6 weeks with three training sessions/week each lasting 45-60 min. RST comprised frontal and lateral sprint exercises using an expander system with increasing levels of resistance that was attached to a treadmill (h/p/cosmos). TPT included ballistic strength training at 40\% of the one-repetition-maximum for the lower limbs (e.g., leg press, knee extensions). Before and after training, sprint (20-m sprint), change-of-direction speed (T-agility test), jump (drop, countermovement jump), and balance performances (Y balance test) were assessed. ANCOVA statistics revealed large main effects of group for 20-m sprint velocity and ground contact time (0.81 ≤ d ≤ 1.00). Post-hoc tests showed higher sprint velocity following RST and TPT (0.69 ≤ d ≤ 0.82) when compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to 4.5\% for RST [90\%CI: (-1.1\%;10.1\%), d = 1.23] and 2.6\% for TPT [90\%CI: (0.4\%;4.8\%), d = 1.59]. Additionally, ground contact times during sprinting were shorter following RST and TPT (0.68 ≤ d ≤ 1.09) compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to -6.3\% for RST [90\%CI: (-11.4\%;-1.1\%), d = 1.45) and -2.7\% for TPT [90\%CI: (-4.2\%;-1.2\%), d = 2.36]. Finally, effects for change-of-direction speed, jump, and balance performance varied from small-to-large. The present findings indicate that 6 weeks of RST and TPT produced similar effects on 20-m sprint performance compared with a passive control in healthy and physically active, young adults. However, no training-related effects were found for change-of-direction speed, jump and balance performance. We conclude that both training regimes can be applied for speed development.}, language = {en} } @misc{ChaabeneNegraBouguezzietal.2018, author = {Chaabene, Helmi and Negra, Yassine and Bouguezzi, Raja and Capranica, Laura and Franchini, Emerson and Prieske, Olaf and Hbacha, Hamdi and Granacher, Urs}, title = {Tests for the Assessment of Sport-Specific Performance in Olympic Combat Sports}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {436}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-411959}, pages = {18}, year = {2018}, abstract = {The regular monitoring of physical fitness and sport-specific performance is important in elite sports to increase the likelihood of success in competition. This study aimed to systematically review and to critically appraise the methodological quality, validation data, and feasibility of the sport-specific performance assessment in Olympic combat sports like amateur boxing, fencing, judo, karate, taekwondo, and wrestling. A systematic search was conducted in the electronic databases PubMed, Google-Scholar, and Science-Direct up to October 2017. Studies in combat sports were included that reported validation data (e.g., reliability, validity, sensitivity) of sport-specific tests. Overall, 39 studies were eligible for inclusion in this review. The majority of studies (74\%) contained sample sizes <30 subjects. Nearly, 1/3 of the reviewed studies lacked a sufficient description (e.g., anthropometrics, age, expertise level) of the included participants. Seventy-two percent of studies did not sufficiently report inclusion/exclusion criteria of their participants. In 62\% of the included studies, the description and/or inclusion of a familiarization session (s) was either incomplete or not existent. Sixty-percent of studies did not report any details about the stability of testing conditions. Approximately half of the studies examined reliability measures of the included sport-specific tests (intraclass correlation coefficient [ICC] = 0.43-1.00). Content validity was addressed in all included studies, criterion validity (only the concurrent aspect of it) in approximately half of the studies with correlation coefficients ranging from r = -0.41 to 0.90. Construct validity was reported in 31\% of the included studies and predictive validity in only one. Test sensitivity was addressed in 13\% of the included studies. The majority of studies (64\%) ignored and/or provided incomplete information on test feasibility and methodological limitations of the sport-specific test. In 28\% of the included studies, insufficient information or a complete lack of information was provided in the respective field of the test application. Several methodological gaps exist in studies that used sport-specific performance tests in Olympic combat sports. Additional research should adopt more rigorous validation procedures in the application and description of sport-specific performance tests in Olympic combat sports.}, language = {en} } @article{LesinskiPrieskeBordeetal.2018, author = {Lesinski, Melanie and Prieske, Olaf and Borde, Ron and Beurskens, Rainer and Granacher, Urs}, title = {Effects of Different Footwear Properties and Surface Instability on Neuromuscular Activity and Kinematics During Jumping}, series = {Journal of strength and conditioning research : the research journal of the NSCA}, volume = {32}, journal = {Journal of strength and conditioning research : the research journal of the NSCA}, number = {11}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1064-8011}, doi = {10.1519/JSC.0000000000002556}, pages = {3246 -- 3257}, year = {2018}, abstract = {The purpose of this study was to examine sex-specific effects of different footwear properties vs. barefoot condition during the performance of drop jumps (DJs) on stable and unstable surfaces on measures of jump performance, electromyographic (EMG) activity, and knee joint kinematics. Drop jump performance, EMG activity of lower-extremity muscles, as well as sagittal and frontal knee joint kinematics were tested in 28 healthy male (n = 14) and female (n = 14) physically active sports science students (23 6 2 years) during the performance of DJs on stable and unstable surfaces using different footwear properties (elastic vs. minimal shoes) vs. barefoot condition. Analysis revealed a significantly lower jump height and performance index (Delta 7-12\%; p < 0.001; 2.22 <= d = 2.90) during DJs on unstable compared with stable surfaces. This was accompanied by lower thigh/shank muscle activities (Delta 11-28\%; p < 0.05; 0.99 <= d = 2.16) and knee flexion angles (Delta 5-8\%; p < 0.05; 1.02 <= d = 2.09). Furthermore, knee valgus angles during DJs were significantly lower when wearing shoes compared with barefoot condition (Delta 22-32\%; p < 0.01; 1.38 <= d = 3.31). Sex-specific analyses indicated higher knee flexion angles in females compared with males during DJs, irrespective of the examined surface and footwear conditions (Delta 29\%; p < 0.05; d = 0.92). Finally, hardly any significant footwear-surface interactions were detected. Our findings revealed that surface instability had an impact on DJ performance, thigh/shank muscle activity, and knee joint kinematics. In addition, the single factors "footwear" and "sex" modulated knee joint kinematics during DJs. However, hardly any significant interaction effects were found. Thus, additional footwear-related effects can be neglected when performing DJs during training on different surfaces.}, language = {en} } @misc{GaeblerPrieskeHortobagyietal.2018, author = {Gaebler, Martijn and Prieske, Olaf and Hortobagyi, Tibor and Granacher, Urs}, title = {The effects of concurrent strength and endurance training on physical fitness and athletic performance in Youth}, series = {Frontiers in physiology}, volume = {9}, journal = {Frontiers in physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2018.01057}, pages = {13}, year = {2018}, abstract = {Combining training of muscle strength and cardiorespiratory fitness within a training cycle could increase athletic performance more than single-mode training. However, the physiological effects produced by each training modality could also interfere with each other, improving athletic performance less than single-mode training. Because anthropometric, physiological, and biomechanical differences between young and adult athletes can affect the responses to exercise training, young athletes might respond differently to concurrent training (CT) compared with adults. Thus, the aim of the present systematic review with meta-analysis was to determine the effects of concurrent strength and endurance training on selected physical fitness components and athletic performance in youth. A systematic literature search of PubMed and Web of Science identified 886 records. The studies included in the analyses examined children (girls age 6-11 years, boys age 6-13 years) or adolescents (girls age 12-18 years, boys age 14-18 years), compared CT with single-mode endurance (ET) or strength training (ST), and reported at least one strength/power-(e.g., jump height), endurance-(e.g., peak. VO2, exercise economy), or performance-related (e.g., time trial) outcome. We calculated weighted standardized mean differences (SMDs). CT compared to ET produced small effects in favor of CT on athletic performance (n = 11 studies, SMD = 0.41, p = 0.04) and trivial effects on cardiorespiratory endurance (n = 4 studies, SMD = 0.04, p = 0.86) and exercise economy (n = 5 studies, SMD = 0.16, p = 0.49) in young athletes. A sub-analysis of chronological age revealed a trend toward larger effects of CT vs. ET on athletic performance in adolescents (SMD = 0.52) compared with children (SMD = 0.17). CT compared with ST had small effects in favor of CT on muscle power (n = 4 studies, SMD = 0.23, p = 0.04). In conclusion, CT is more effective than single-mode ET or ST in improving selected measures of physical fitness and athletic performance in youth. Specifically, CT compared with ET improved athletic performance in children and particularly adolescents. Finally, CT was more effective than ST in improving muscle power in youth.}, language = {en} } @article{ChaabeneNegraBouguezzietal.2018, author = {Chaabene, Helmi and Negra, Yassine and Bouguezzi, Raja and Capranica, Laura and Franchini, Emerson and Prieske, Olaf and Hbacha, Hamdi and Granacher, Urs}, title = {Tests for the Assessment of Sport-Specific Performance in Olympic Combat Sports}, series = {Frontiers in Physiology}, volume = {9}, journal = {Frontiers in Physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2018.00386}, pages = {1 -- 18}, year = {2018}, abstract = {The regular monitoring of physical fitness and sport-specific performance is important in elite sports to increase the likelihood of success in competition. This study aimed to systematically review and to critically appraise the methodological quality, validation data, and feasibility of the sport-specific performance assessment in Olympic combat sports like amateur boxing, fencing, judo, karate, taekwondo, and wrestling. A systematic search was conducted in the electronic databases PubMed, Google-Scholar, and Science-Direct up to October 2017. Studies in combat sports were included that reported validation data (e.g., reliability, validity, sensitivity) of sport-specific tests. Overall, 39 studies were eligible for inclusion in this review. The majority of studies (74\%) contained sample sizes <30 subjects. Nearly, 1/3 of the reviewed studies lacked a sufficient description (e.g., anthropometrics, age, expertise level) of the included participants. Seventy-two percent of studies did not sufficiently report inclusion/exclusion criteria of their participants. In 62\% of the included studies, the description and/or inclusion of a familiarization session (s) was either incomplete or not existent. Sixty-percent of studies did not report any details about the stability of testing conditions. Approximately half of the studies examined reliability measures of the included sport-specific tests (intraclass correlation coefficient [ICC] = 0.43-1.00). Content validity was addressed in all included studies, criterion validity (only the concurrent aspect of it) in approximately half of the studies with correlation coefficients ranging from r = -0.41 to 0.90. Construct validity was reported in 31\% of the included studies and predictive validity in only one. Test sensitivity was addressed in 13\% of the included studies. The majority of studies (64\%) ignored and/or provided incomplete information on test feasibility and methodological limitations of the sport-specific test. In 28\% of the included studies, insufficient information or a complete lack of information was provided in the respective field of the test application. Several methodological gaps exist in studies that used sport-specific performance tests in Olympic combat sports. Additional research should adopt more rigorous validation procedures in the application and description of sport-specific performance tests in Olympic combat sports.}, language = {en} } @article{PrieskeDalagerHerzetal.2019, author = {Prieske, Olaf and Dalager, Tina and Herz, Michael and Hortobagyi, Tibor and Sjogaard, Gisela and Sogaard, Karen and Granacher, Urs}, title = {Effects of Physical Exercise Training in the Workplace on Physical Fitness: A Systematic Review and Meta-analysis}, series = {Sports medicine}, volume = {49}, journal = {Sports medicine}, number = {12}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-019-01179-6}, pages = {1903 -- 1921}, year = {2019}, abstract = {Background There is evidence that physical exercise training (PET) conducted at the workplace is effective in improving physical fitness and thus health. However, there is no current systematic review available that provides high-level evidence regarding the effects of PET on physical fitness in the workforce. Objectives To quantify sex-, age-, and occupation type-specific effects of PET on physical fitness and to characterize dose-response relationships of PET modalities that could maximize gains in physical fitness in the working population. Data Sources A computerized systematic literature search was conducted in the databases PubMed and Cochrane Library (2000-2019) to identify articles related to PET in workers. Study Eligibility Criteria Only randomized controlled trials with a passive control group were included if they investigated the effects of PET programs in workers and tested at least one fitness measure. Study Appraisal and Synthesis Methods Weighted mean standardised mean differences (SMDwm) were calculated using random effects models. A multivariate random effects meta-regression was computed to explain the influence of key training modalities (e.g., training frequency, session duration, intensity) on the effectiveness of PET on measures of physical fitness. Further, subgroup univariate analyses were computed for each training modality. Additionally, methodological quality of the included studies was rated with the help of the Physiotherapy Evidence Database (PEDro) Scale. Results Overall, 3423 workers aged 30-56 years participated in 17 studies (19 articles) that were eligible for inclusion. Methodological quality of the included studies was moderate with a median PEDro score of 6. Our analyses revealed significant, small-sized effects of PET on cardiorespiratory fitness (CRF), muscular endurance, and muscle power (0.29 <= SMDwm <= 0.48). Medium effects were found for CRF and muscular endurance in younger workers (<= 45 years) (SMDwm = 0.71) and white-collar workers (SMDwm = 0.60), respectively. Multivariate random effects meta-regression for CRF revealed that none of the examined training modalities predicted the effects of PET on CRF (R-2 = 0). Independently computed subgroup analyses showed significant PET effects on CRF when conducted for 9-12 weeks (SMDwm = 0.31) and for 17-20 weeks (SMDwm = 0.74). Conclusions PET effects on physical fitness in healthy workers are moderated by age (CRF) and occupation type (muscular endurance). Further, independently computed subgroup analyses indicated that the training period of the PET programs may play an important role in improving CRF in workers.}, language = {en} } @article{ChaabeneNegraCapranicaetal.2019, author = {Chaabene, Helmi and Negra, Yassine and Capranica, Laura and Prieske, Olaf and Granacher, Urs}, title = {A Needs Analysis of Karate Kumite With Recommendations for Performance Testing and Training}, series = {Strength and conditioning journal}, volume = {41}, journal = {Strength and conditioning journal}, number = {3}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1524-1602}, doi = {10.1519/SSC.0000000000000445}, pages = {35 -- 46}, year = {2019}, abstract = {An effective training program needs to be customized to the specific demands of the redpective sport. Therefore, it is important to conduct a needs analysis to gain information on the unique characteristics of the sport. The objectives of thes review were (A) to conduct a systematic needs analysis of karate kumite and (B) to provide practical recommendations for sport-specific performance testing and training of karate kumite athletes.}, 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} } @article{ZinkeGebelGranacheretal.2019, author = {Zinke, Fridolin and Gebel, Arnd and Granacher, Urs and Prieske, Olaf}, title = {Acute Effects of Short-Term Local Tendon Vibration on Plantar Flexor Torque, Muscle Contractile Properties, Neuromuscular and Brain Activity in Young Athletes}, series = {Journal of sports science \& medicine}, volume = {18}, journal = {Journal of sports science \& medicine}, number = {2}, publisher = {Department of Sports Medicine, Medical Faculty of Uludag University}, address = {Bursa}, issn = {1303-2968}, pages = {327 -- 336}, year = {2019}, abstract = {The purpose of this study was to examine the acute effects of short-term Achilles tendon vibration on plantar flexor torque, twitch contractile properties as well as muscle and cortical activity in young athletes. Eleven female elite soccer players aged 15.6 +/- 0.5 years participated in this study. Three different conditions were applied in randomized order: Achilles tendon vibration (80 Hz) for 30 and 300 s, and a passive control condition (300 s). Tests at baseline and following conditions included the assessment of peak plantar flexor torque during maximum voluntary contraction, electrically evoked muscle twitches (e.g., potentiated twitch peak torque [PT]), and electromyographic (EMG) activity of the plantar flexors. Additionally, electroencephalographic (EEG) activity of the primary motor and somatosensory cortex were assessed during a submaximal dynamic concentric-eccentric plantar flexion exercise using an elastic rubber band. Large-sized main effects of condition were found for EEG absolute alpha-1 and beta-1 band power (p <= 0.011; 1.5 <= d <= 2.6). Post-hoc tests indicated that alpha-1 power was significantly lower at 30 and 300 s (p = 0.009; d = 0.8) and beta-1 power significantly lower at 300 s (p < 0.001; d = 0.2) compared to control condition. No significant effect of condition was found for peak plantar flexor torque, electrical evoked muscle twitches, and EMG activity. In conclusion, short-term local Achilles tendon vibration induced lower brain activity (i.e., alpha-1 and beta-1 band power) but did not affect lower limb peak torque, twitch contractile properties, and muscle activity. Lower brain activity following short-term local Achilles tendon vibration may indicate improved cortical function during a submaximal dynamic exercise in female young soccer players.}, language = {en} } @misc{ChaabenePrieskeLesinskietal.2019, author = {Chaabene, Helmi and Prieske, Olaf and Lesinski, Melanie and Sandau, Ingo and Granacher, Urs}, title = {Short-term seasonal development of anthropometry, body composition, physical fitness, and sport-specific performance in young olympic weightlifters}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {685}, issn = {1866-8364}, doi = {10.25932/publishup-47260}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472609}, pages = {15}, year = {2019}, abstract = {The aim of this study is to monitor short-term seasonal development of young Olympic weightlifters' anthropometry, body composition, physical fitness, and sport-specific performance. Fifteen male weightlifters aged 13.2 ± 1.3 years participated in this study. Tests for the assessment of anthropometry (e.g., body-height, body-mass), body-composition (e.g., lean-body-mass, relative fat-mass), muscle strength (grip-strength), jump performance (drop-jump (DJ) height, countermovement-jump (CMJ) height, DJ contact time, DJ reactive-strength-index (RSI)), dynamic balance (Y-balance-test), and sport-specific performance (i.e., snatch and clean-and-jerk) were conducted at different time-points (i.e., T1 (baseline), T2 (9 weeks), T3 (20 weeks)). Strength tests (i.e., grip strength, clean-and-jerk and snatch) and training volume were normalized to body mass. Results showed small-to-large increases in body-height, body-mass, lean-body-mass, and lower-limbs lean-mass from T1-to-T2 and T2-to-T3 (∆0.7-6.7\%; 0.1 ≤ d ≤ 1.2). For fat-mass, a significant small-sized decrease was found from T1-to-T2 (∆13.1\%; d = 0.4) and a significant increase from T2-to-T3 (∆9.1\%; d = 0.3). A significant main effect of time was observed for DJ contact time (d = 1.3) with a trend toward a significant decrease from T1-to-T2 (∆-15.3\%; d = 0.66; p = 0.06). For RSI, significant small increases from T1-to-T2 (∆9.9\%, d = 0.5) were noted. Additionally, a significant main effect of time was found for snatch (d = 2.7) and clean-and-jerk (d = 3.1) with significant small-to-moderate increases for both tests from T1-to-T2 and T2-to-T3 (∆4.6-11.3\%, d = 0.33 to 0.64). The other tests did not change significantly over time (0.1 ≤ d ≤ 0.8). Results showed significantly higher training volume for sport-specific training during the second period compared with the first period (d = 2.2). Five months of Olympic weightlifting contributed to significant changes in anthropometry, body-composition, and sport-specific performance. However, hardly any significant gains were observed for measures of physical fitness. Coaches are advised to design training programs that target a variety of fitness components to lay an appropriate foundation for later performance as an elite athlete.}, language = {en} } @article{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 = {Frontiers in Physiology}, volume = {10}, journal = {Frontiers in Physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2019.00782}, 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} } @article{PrieskeChaabenePutaetal.2019, author = {Prieske, Olaf and Chaabene, Helmi and Puta, Christian and Behm, David George and B{\"u}sch, Dirk and Granacher, Urs}, title = {Effects of Drop Height on Jump Performance in Male and Female Elite Adolescent Handball Players}, series = {International journal of sports physiology and performance}, volume = {14}, journal = {International journal of sports physiology and performance}, number = {5}, publisher = {Human Kinetics Publ.}, address = {Champaign}, issn = {1555-0265}, doi = {10.1123/ijspp.2018-0482}, pages = {674 -- 680}, year = {2019}, abstract = {Purpose: To examine the effects of drop height on drop-jump (DJ) performance and on associations between DJ and horizontal-jump/sprint performances in adolescent athletes. Methods: Male (n = 119, 2.5 [0.6] y post-peak-height velocity) and female (n = 120, 2.5 [0.5] y post-peak-height velocity) adolescent handball players (national level) performed DJs in randomized order using 3 drop heights (20, 35, and 50 cm). DJ performance (jump height, reactive strength index [RSI]) was analyzed using the Optojump Next system. In addition, correlations were computed between DJ height and RSI with standing-long-jump and 20-m linear-sprint performances. Results: Statistical analyses revealed medium-size main effects of drop height for DJ height and RSI (P <.001, 0.63 <= d <= 0.71). Post hoc tests indicated larger DJ heights from 20 to 35 and 35 to 50 cm (P <=.031, 0.33 <= d <= 0.71) and better RSI from 20- to 35-cm drop height (P <.001, d = 0.77). No significant difference was found for RSI between 35- and 50-cm drop height. Irrespective of drop height, associations of DJ height and RSI were small with 5-m-split time (-.27 <= r <=.05), medium with 10-m-split time (-.44 <= r <=.14), and medium to large with 20-m sprint time and standing-long-jump distance (-.57 <= r <=.22). Conclusions: The present findings indicate that, irrespective of sex, 35-cm drop heights are best suited to induce rapid and powerful DJ performance (ie, RSI) during reactive strength training in elite adolescent handball players. Moreover, training-related gains in DJ performance may at least partly translate to gains in horizontal jump and longer sprint distances (ie, >= 20-m) and/or vice versa in male and female elite adolescent athletes, irrespective of drop height.}, language = {en} } @article{ChaabenePrieskeLesinskietal.2019, author = {Chaabene, Helmi and Prieske, Olaf and Lesinski, Melanie and Sandau, Ingo and Granacher, Urs}, title = {Short-Term Seasonal Development of Anthropometry, Body Composition, Physical Fitness, and Sport-Specific Performance in Young Olympic Weightlifters}, series = {Sports}, volume = {7}, journal = {Sports}, number = {12}, publisher = {MDPI}, address = {Basel}, issn = {2075-4663}, doi = {10.3390/sports7120242}, pages = {13}, year = {2019}, language = {en} } @article{NegraChaabeneFernandezFernandezetal.2020, author = {Negra, Yassine and Chaabene, Helmi and Fernandez-Fernandez, Jaime and Sammoud, Senda and Bouguezzi, Raja and Prieske, Olaf and Granacher, Urs}, title = {Short-term plyometric Jump training improves repeated-sprint ability in prepuberal male soccer players}, series = {Journal of strength and conditioning research : the research journal of the NSCA}, volume = {34}, journal = {Journal of strength and conditioning research : the research journal of the NSCA}, number = {11}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1064-8011}, doi = {10.1519/JSC.0000000000002703}, pages = {3241 -- 3249}, year = {2020}, abstract = {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.}, language = {en} } @article{PrieskeChaabeneGaebleretal.2020, author = {Prieske, Olaf and Chaabene, Helmi and G{\"a}bler, Martijn and Herz, Michael and Helm, Norman and Markov, Adrian and Granacher, Urs}, title = {Seasonal changes in anthropometry, body composition, and physical fitness and the relationships with sporting success in young sub-elite judo athletes}, series = {International journal of environmental research and public health : IJERPH}, volume = {17}, journal = {International journal of environmental research and public health : IJERPH}, number = {19}, publisher = {MDPI AG}, address = {Basel}, issn = {1660-4601}, doi = {10.3390/ijerph17197169}, pages = {17}, year = {2020}, abstract = {This exploratory study aimed to monitor long-term seasonal developments in measures of anthropometry, body composition, and physical fitness in young judo athletes, and to compute associations between these measures and sporting success. Forty-four young judoka (20 females, 24 males) volunteered to participate. Tests for the assessment of anthropometry (e.g., body height/mass), body-composition (e.g., lean body mass), muscle strength (isometric handgrip strength), vertical jumping (e.g., countermovement-jump (CMJ) height), and dynamic balance (Y-balance test) were conducted at the beginning and end of a 10-month training season. Additionally, sporting success at the end of the season was recorded for each athlete. Analyses revealed significant time x sex interaction effects for lean-body-mass, isometric handgrip strength, and CMJ height (0.7 <= d <= 1.6). Post-hoc analyses showed larger gains for all measures in young males (1.9 <= d <= 6.0) compared with females (d = 2.4) across the season. Additionally, significant increases in body height and mass as well as Y-balance test scores were found from pre-to-post-test (1.2 <= d <= 4.3), irrespective of sex. Further, non-significant small-to-moderate-sized correlations were identified between changes in anthropometry/body composition/physical fitness and sporting success (p > 0.05; -0.34 <= rho <= 0.32). Regression analysis confirmed that no model significantly predicted sporting success. Ten months of judo training and/or growth/maturation contributed to significant changes in anthropometry, body composition, and physical fitness, particularly in young male judo athletes.}, language = {en} } @article{HelmPrieskeMuehlbaueretal.2020, author = {Helm, Norman and Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Retzlaff, Matthias and Granacher, Urs}, title = {Associations between trunk muscle strength and judo-specific pulling performances in judo athletes}, series = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, volume = {34}, journal = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, number = {1}, publisher = {Thieme}, address = {Stuttgart}, issn = {0932-0555}, doi = {10.1055/a-0677-9608}, pages = {18 -- 27}, year = {2020}, abstract = {Background: Good trunk stability is an important prerequisite for the mobility of the upper and lower limbs during sport-specific movements. Therefore, trunk muscle strength may represent an important performance determinant for judo-specific movements. This study aimed at evaluating statistical correlations between trunk muscle strength and kinetic parameters during judo-specific pulling movements in judo players. Method: Twenty-one male sub-elite judo players aged 22 +/- 4 years with a mean training volume of 15 +/- 4 hours per week participated in this study. Peak isokinetic torque (PIT) of the trunk flexors (PITFlex), extensors (PITEx) and rotators (PITRot) was tested using an isokinetic dynamometer (IsoMed 2000). In addition, two kinetic parameters (mechanical work [W], maximal force [F-max]) were analysed using the judo-specific measurement and information system JERGo (c). For this purpose, athletes were asked to do their judo-specific pulling movements while standing and with a dynamic change of position (i.e. Morote-seoi-nage). Results: Regarding pulling movements while standing, significant correlations (0.62 <= r(P) <= 0.72) were found between isokinetic tests (PITFlex, PITEx, PITRot) and mechanical work during judo-specific movement. Further, significant correlations (0.59 <= r(P) <= 0.65) were detected between isokinetic tests (PITEx, PITRot) and judo-specific pulling movements (Fmax). Regarding pulling movements with a change of position, significant correlations (0.47 <= r(P) <= 0.88) were observed between isokinetics (PITFlex, PITEx, PITRot) and the kinetic pulling parameters (W, Fmax), irrespective of the examined arm. No significant differences in magnitude of correlation coefficients were found between PIT of the trunk flexors, extensors, and rotators and judo-specific movements. Further, the regression analysis indicated that PIT of the trunk extensors is the single best predictor for mechanical work during pulling movements while standing (46.9 \%). Trunk rotator PIT is the single best predictor for mechanical work during pulling movements with a change of position (69.4 \%). Conclusions: Findings from this study indicate that trunk muscle strength, particularly trunk rotator PIT is associated with kinetic pulling variables during pulling movements with a change of position. This implies that the development of trunk rotator strength could have an impact on pulling movements with a change of position (i.e. Morote-seoi-nage) in judo athletes.}, language = {de} } @article{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 = {Frontiers in Physiology}, volume = {11}, journal = {Frontiers in Physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2020.00888}, pages = {12}, 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} } @article{ThielePrieskeChaabeneetal.2020, author = {Thiele, Dirk and Prieske, Olaf and Chaabene, Helmi and Granacher, Urs}, title = {Effects of strength training on physical fitness and sport-specific performance in recreational, sub-elite, and elite rowers}, series = {Journal of sports sciences}, volume = {38}, journal = {Journal of sports sciences}, number = {10}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {0264-0414}, doi = {10.1080/02640414.2020.1745502}, pages = {1186 -- 1195}, year = {2020}, abstract = {The purpose of this systematic review with meta-analysis was to examine the effects of strength training (ST) on selected components of physical fitness (e.g., lower/upper limb maximal strength, muscular endurance, jump performance, cardiorespiratory endurance) and sport-specific performance in rowers. Only studies with an active control group were included if they examined the effects of ST on at least one proxy of physical fitness and/or sport-specific performance in rowers. Weighted and averaged standardized mean differences (SMD) were calculated using random-effects models. Subgroup analyses were computed to identify effects of ST type or expertise level on sport-specific performance. Our analyses revealed significant small effects of ST on lower limb maximal strength (SMD = 0.42, p = 0.05) and on sport-specific performance (SMD = 0.32, p = 0.05). Non-significant effects were found for upper limb maximal strength, upper/lower limb muscular endurance, jump performance, and cardiorespiratory endurance. Subgroup analyses for ST type and expertise level showed non-significant differences between the respective subgroups of rowers (p >= 0.32). Our systematic review with meta-analysis indicated that ST is an effective means for improving lower limb maximal strength and sport-specific performance in rowers. However, ST-induced effects are neither modulated by ST type nor rowers' expertise level.}, 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} }