@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} } @article{BeurskensSteinbergAntoniewiczetal.2016, author = {Beurskens, Rainer and Steinberg, Fabian and Antoniewicz, Franziska and Wolff, Wanja and Granacher, Urs}, title = {Neural Correlates of Dual-Task Walking: Effects of Cognitive versus Motor Interference in Young Adults}, series = {Neural plasticity}, journal = {Neural plasticity}, publisher = {Hindawi}, address = {London}, issn = {2090-5904}, doi = {10.1155/2016/8032180}, pages = {9}, year = {2016}, abstract = {Walking while concurrently performing cognitive and/or motor interference tasks is the norm rather than the exception during everyday life and there is evidence from behavioral studies that it negatively affects human locomotion. However, there is hardly any information available regarding the underlying neural correlates of single-and dual-task walking. We had 12 young adults (23.8 +/- 2.8 years) walk while concurrently performing a cognitive interference (CI) or a motor interference (MI) task. Simultaneously, neural activation in frontal, central, and parietal brain areas was registered using a mobile EEG system. Results showed that the MI task but not the CI task affected walking performance in terms of significantly decreased gait velocity and stride length and significantly increased stride time and tempo-spatial variability. Average activity in alpha and beta frequencies was significantly modulated during both CI and MI walking conditions in frontal and central brain regions, indicating an increased cognitive load during dual-task walking. Our results suggest that impaired motor performance during dual-task walking is mirrored in neural activation patterns of the brain. This finding is in line with established cognitive theories arguing that dual-task situations overstrain cognitive capabilities resulting in motor performance decrements.}, language = {en} } @article{LacroixKressigMuehlbaueretal.2016, author = {Lacroix, Andre and Kressig, Reto W. and M{\"u}hlbauer, Thomas and Gschwind, Yves J. and Pfenninger, Barbara and Bruegger, Othmar and Granacher, Urs}, title = {Effects of a Supervised versus an Uniupervised Combined Balance and Strength Training Program on Balance and Muscle Power in Healthy Older Adults: A Randomized Controlled Trial}, series = {Gerontology}, volume = {62}, journal = {Gerontology}, publisher = {Karger}, address = {Basel}, issn = {0304-324X}, doi = {10.1159/000442087}, pages = {275 -- 288}, year = {2016}, abstract = {Background: Losses in lower extremity muscle strength/power, muscle mass and deficits in static and particularly dynamic balance due to aging are associated with impaired functional performance and an increased fall risk. It has been shown that the combination of balance and strength training (BST) mitigates these age-related deficits. However, it is unresolved whether supervised versus unsupervised BST is equally effective in improving muscle power and balance in older adults. Objective:This study examined the impact of a 12-week BST program followed by 12 weeks of detraining on measures of balance and muscle power in healthy older adults enrolled in supervised (SUP) or unsupervised (UNSUP) training. Methods: Sixty-six older adults (men: 25, women: 41; age 73 4 years) were randomly assigned to a SUP group (2/week supervised training, 1/week unsupervised training; n = 22), an UNSUP group (3/week unsupervised training; n = 22) or a passive control group (CON; n = 22). Static (i.e., Romberg Test) and dynamic (i.e., 10-meter walk test) steady-state, proactive (i.e., Timed Up and Go Test, Functional Reach Test), and reactive balance (e.g., Push and Release Test), as well as lower extremity muscle power (i.e., Chair Stand Test; Stair Ascent and Descent Test) were tested before and after the active training phase as well as after detraining. Results: Adherence rates to training were 92\% for SUP and 97\% for UNSUP. BST resulted in significant group x time interactions. Post hoc analyses showed, among others, significant training-related improvements for the Romberg Test, stride velocity, Timed Up and Go Test, and Chair Stand Test in favor of the SUP group. Following detraining, significantly enhanced performances (compared to baseline) were still present in 13 variables for the SUP group and in 10 variables for the UNSUP group. Conclusion: Twelve weeks of BST proved to be safe (no training-related injuries) and feasible (high attendance rates of >90\%). Deficits of balance and lower extremity muscle power can be mitigated by BST in healthy older adults. Additionally, supervised as compared to unsupervised BST was more effective. Thus, it is recommended to counteract intrinsic fall risk factors by applying supervised BST programs for older adults. (C) 2015 The Author(s) Published by S. Karger AG, Basel}, language = {en} } @article{BeijersbergenHortobagyiBeurskensetal.2016, author = {Beijersbergen, Chantal M. I. and Hortobagyi, Tibor and Beurskens, Rainer and Lenzen-Grossimlinghaus, Romana and Gabler, Martijn and Granacher, Urs}, title = {Effects of Power Training on Mobility and Gait Biomechanics in Old Adults with Moderate Mobility Disability: Protocol and Design of the Potsdam Gait Study (POGS)}, series = {Gerontology}, volume = {62}, journal = {Gerontology}, publisher = {Karger}, address = {Basel}, issn = {0304-324X}, doi = {10.1159/000444752}, pages = {597 -- 603}, year = {2016}, abstract = {Background: Walking speed decreases in old age. Even though old adults regularly participate in exercise interventions, we do not know how the intervention-induced changes in physical abilities produce faster walking. The Potsdam Gait Study (POGS) will examine the effects of 10 weeks of power training and detraining on leg muscle power and, for the first time, on complete gait biomechanics, including joint kinematics, kinetics, and muscle activation in old adults with moderate mobility disability. Methods/Design: POGS is a randomized controlled trial with two arms, each crossed over, without blinding. Arm 1 starts with a 10-week control period to assess the reliability of the tests and is then crossed over to complete 25-30 training sessions over 10 weeks. Arm 2 completes 25-30 exercise sessions over 10 weeks, followed by a 10-week follow-up (detraining) period. The exercise program is designed to improve lower extremity muscle power. Main outcome measures are: muscle power, gait speed, and gait biomechanics measured at baseline and after 10 weeks of training and 10 weeks of detraining. Discussion: It is expected that power training will increase leg muscle power measured by the weight lifted and by dynamometry, and these increased abilities become expressed in joint powers measured during gait. Such favorably modified powers will underlie the increase in step length, leading ultimately to a faster walking speed. POGS will increase our basic understanding of the biomechanical mechanisms of how power training improves gait speed in old adults with moderate levels of mobility disabilities. (C) 2016 S. Karger AG, Basel}, language = {en} } @article{BeurskensHaegerKliegletal.2016, author = {Beurskens, Rainer and Haeger, Matthias and Kliegl, Reinhold and Roecker, Kai and Granacher, Urs}, title = {Postural Control in Dual-Task Situations: Does Whole-Body Fatigue Matter?}, series = {PLoS one}, volume = {11}, journal = {PLoS one}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0147392}, pages = {1379 -- 1384}, year = {2016}, abstract = {Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single-(ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 +/- 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2-21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9-2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3-4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9-3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.}, 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} } @misc{LesinskiHortobagyiMuehlbaueretal.2016, author = {Lesinski, Melanie and Hortobagyi, Tibor and M{\"u}hlbauer, Thomas and Gollhofer, Albert and Granacher, Urs}, title = {Effects of Balance Training on Balance Performance in Healthy Older Adults: A Systematic Review and Meta-analysis (vol 45, pg 1721, 2015)}, series = {Sports medicine}, volume = {46}, journal = {Sports medicine}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-016-0500-6}, pages = {457 -- 457}, year = {2016}, language = {en} } @misc{LesinskiHortobagyiMuehlbaueretal.2016, author = {Lesinski, Melanie and Hortobagyi, Tibor and M{\"u}hlbauer, Thomas and Gollhofer, Albert and Granacher, Urs}, title = {Dose-Response Relationships of Balance Training in Healthy Young Adults: A Systematic Review and Meta-Analysis (vol 45, pg 557, 2015)}, series = {Sports medicine}, volume = {46}, journal = {Sports medicine}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-016-0499-8}, pages = {455 -- 455}, year = {2016}, language = {en} } @misc{HortobagyiLesinskiGableretal.2016, author = {Hortobagyi, Tibor and Lesinski, Melanie and Gabler, Martijn and VanSwearingen, Jessie M. and Malatesta, Davide and Granacher, Urs}, title = {Gait Speed: A Systematic Review and Meta-Analysis (vol 45, pg 1627, 2015)}, series = {Sports medicine}, volume = {46}, journal = {Sports medicine}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-016-0498-9}, pages = {453 -- 453}, year = {2016}, language = {en} } @misc{BehmMuehlbauerKibeleetal.2016, author = {Behm, David George and M{\"u}hlbauer, Thomas and Kibele, Armin and Granacher, Urs}, title = {Effects of Strength Training Using Unstable Surfaces on Strength, Power and Balance Performance Across the Lifespan: A Systematic Review and Meta-analysis (vol 45, pg 1645, 2015)}, series = {Sports medicine}, volume = {46}, journal = {Sports medicine}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-016-0497-x}, pages = {451 -- 451}, year = {2016}, language = {en} }