TY - JOUR A1 - Beurskens, Rainer A1 - Haeger, Matthias A1 - Kliegl, Reinhold A1 - Roecker, Kai A1 - Granacher, Urs T1 - Postural Control in Dual-Task Situations BT - Does Whole-Body Fatigue Matter? JF - PLoS one N2 - 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. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0147392 SN - 1932-6203 VL - 11 IS - 1 SP - 1 EP - 15 PB - PLoS CY - Lawrence, Kan. ER - TY - JOUR A1 - Beurskens, Rainer A1 - Mühlbauer, Thomas A1 - Grabow, Lena A1 - Kliegl, Reinhold A1 - Granacher, Urs T1 - Effects of Backpack Carriage on Dual-Task Performance in Children During Standing and Walking JF - Journal of motor behavior KW - attentional demand KW - cognitive performance KW - gait analysis KW - load carriage KW - postural control Y1 - 2016 U6 - https://doi.org/10.1080/00222895.2016.1152137 SN - 0022-2895 SN - 1940-1027 VL - 48 SP - 500 EP - 508 PB - Wiley-VCH CY - Abingdon ER - TY - JOUR A1 - Beijersbergen, Chantal M. I. A1 - Hortobagyi, Tibor A1 - Beurskens, Rainer A1 - Lenzen-Grossimlinghaus, Romana A1 - Gabler, Martijn A1 - Granacher, Urs T1 - 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) JF - Gerontology N2 - 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 KW - Aging KW - Walking speed KW - Exercise KW - Muscle power KW - Gait kinematics KW - Gait kinetics Y1 - 2016 U6 - https://doi.org/10.1159/000444752 SN - 0304-324X SN - 1423-0003 VL - 62 SP - 597 EP - 603 PB - Karger CY - Basel ER - TY - GEN A1 - Hortobagyi, Tibor A1 - Lesinski, Melanie A1 - Gabler, Martijn A1 - VanSwearingen, Jessie M. A1 - Malatesta, Davide A1 - Granacher, Urs T1 - Gait Speed: A Systematic Review and Meta-Analysis (vol 45, pg 1627, 2015) T2 - Sports medicine Y1 - 2016 U6 - https://doi.org/10.1007/s40279-016-0498-9 SN - 0112-1642 SN - 1179-2035 VL - 46 SP - 453 EP - 453 PB - Springer CY - Northcote ER - TY - GEN A1 - Lesinski, Melanie A1 - Hortobagyi, Tibor A1 - Mühlbauer, Thomas A1 - Gollhofer, Albert A1 - Granacher, Urs T1 - Effects of Balance Training on Balance Performance in Healthy Older Adults: A Systematic Review and Meta-analysis (vol 45, pg 1721, 2015) T2 - Sports medicine Y1 - 2016 U6 - https://doi.org/10.1007/s40279-016-0500-6 SN - 0112-1642 SN - 1179-2035 VL - 46 SP - 457 EP - 457 PB - Springer CY - Northcote ER - TY - JOUR A1 - Lesinski, Melanie A1 - Prieske, Olaf A1 - Demps, Marie A1 - Granacher, Urs T1 - Effects of fatigue and surface instability on neuromuscular performance during jumping JF - Der Schmerz : Organ der Deutschen Gesellschaft zum Studium des Schmerzes, der Österreichischen Schmerzgesellschaft und der Deutschen Interdisziplinären Vereinigung für Schmerztherapie N2 - 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. KW - Exhaustion KW - stretch-shortening cycle KW - jump height KW - EMG KW - athlete. Y1 - 2016 U6 - https://doi.org/10.1111/sms.12548 SN - 0905-7188 SN - 1600-0838 VL - 26 SP - 1140 EP - 1150 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wallenta, Christopher A1 - Granacher, Urs A1 - Lesinski, Melanie A1 - Schuenemann, C. A1 - Mühlbauer, Thomas T1 - Effects of Complex Versus Block Strength Training on the Athletic Performance of Elite Youth Soccer Players JF - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation N2 - Hintergrund: Kraft und Schnelligkeit stellen bedeutsame leistungsdeterminierende Faktoren im Fußball dar. Durch Komplextraining (Kombination aus Kraft- und plyometrischen Übungen in einer Trainingseinheit) lassen sich Kraft- und Schnelligkeitswerte von Athleten steigern. Unklar ist jedoch, ob ein Komplextraining (KT) gegenüber einem herkömmlichen blockweisen Krafttraining (BT) zu größeren sportmotorischen Leistungssteigerungen führt. Das Ziel der Studie war es, die Effekte von KT versus BT auf Variablen der Kraft, Schnelligkeit und Gewandtheit von Nachwuchsleistungsfußballern zu untersuchen. Methode: Zusätzlich zum regulären Fußballtraining (ca. 6 × pro Woche, je 60 – 90 min.) führten 18 männliche Nachwuchsleistungsfußballer über sechs Wochen (2 × pro Woche, je 30 min.) entweder ein progressives KT (n = 10, Alter: 18,5 ± 2,2 Jahre) oder BT (n = 8, Alter: 18,1 ± 1,6 Jahre) durch. Vor und nach dem Training wurden Tests zur Erfassung der Kraft (Einer-Wiederholungs-Maximum [EWM] Kniebeuge), der Sprungkraft (Hockstrecksprung [HSS]), der Schnelligkeit (30-m-Sprint) und der Gewandtheit (T-Test) durchgeführt. Es wurden parameterfreie Verfahren zur Bestimmung von Unterschieden innerhalb (Wilcoxon-Test) und zwischen (Mann-Whitney-U-Test) den beiden Gruppen gerechnet. Ergebnisse: Sowohl KT als auch BT sind sichere (keine trainings- aber sechs spielbedingte Verletzungen) und geeignete (Trainingsteilnahme in KT und BT: ≥ 80 %) Trainingsmaßnahmen in Ergänzung zum regulären Fußballtraining. Die statistische Analyse ergab signifikante Verbesserungen vom Prä- zum Posttest für die KT-Gruppe im EWM (p = 0,043) und im HSS (p = 0,046) sowie für die BT-Gruppe in der Sprintzeit über 5 m (p = 0,039) und 10 m (p = 0,026). Zudem zeigten sich für beide Gruppen signifikante Verbesserungen im T-Test (KT: p = 0,046; BT: p = 0,027). Der Gruppenvergleich (KT vs. BT) über die Zeit (Post- minus Prätest) offenbarte keine bedeutsamen Unterschiede. Schlussfolgerung: Sowohl sechswöchiges KT als auch BT führten zu signifikanten Verbesserungen sportmotorischer Leistungen bei Nachwuchsleistungsfußballern. Allerdings konnten keine zusätzlich leistungssteigernden Effekte von KT im Vergleich zu BT ermittelt werden. In zukünftigen Studien sollte geprüft werden, ob die beobachteten testspezifischen Veränderungen, d. h. Verbesserung der Kraft/Sprungkraft in der KT-Gruppe und Verbesserung der Schnelligkeit in der BT-Gruppe der gewählten Übungsanordnung geschuldet sind oder einen generellen Effekt darstellen. Background: Muscle strength and speed are important determinants of soccer performance. It has previously been shown that complex training (CT, combination of strength and plyometric exercises within a single training session) is effective to enhance strength and speed performance in athletes. However, it is unresolved whether CT is more effective than conventional strength training that is delivered in one single block (BT) to increase proxies of athletic performance. Thus, the aim of the present study was to investigate the effects of CT versus BT on measures of muscle strength/power, speed, and agility in elite youth soccer players. Methods: Eighteen male elite youth soccer players conducted six weeks (2 sessions/week, 30 min, each) of progressive CT (n = 10, age: 18,5 +/- 2.2 years) or BT (n=8, age: 18.1 +/- 1.6 years) in addition to their regular soccer training (approx. 6 sessions/week, 60-90 min, each). Before and after training, tests were conducted for the assessment of strength (one -repetition maximum [1RM] squat), power (countermovement jump [CMJ]), speed (30-m linear sprint), and agility (T test). Non-parametric analyses were used to calculate differences within (Wilcoxon test) and between (Mann-Whitney-U test) groups. Results: Both CT and BT proved to be safe (i.e. no training-related, but six match -related injuries reported) and feasible (i.e. attendance rate of 80% in both groups) training regimens when implemented in addition to regular soccer training. The statistical analysis revealed significant improvements from pre-training to post-training tests for the CT group in 1 RM squat (p =0.043) and CMJ height (p =0,046). For the BT -group, significantly enhanced sprint times were observed over 5 m (p = 0.039) and 10 m (p = 0.026), Furthermore, both groups significantly improved their t test time (CT: p =0.046; BT: p =0.027). However, group comparisons (CT vs. BT) over time (post-training minus pre-training test) did not show any significant differences. Conclusion: Six weeks of CT and BT resulted in significant improvements in proxies of athletic performance. Yet CT did not produce any additional effects compared to BT. Future research is needed to examine whether the observed test-specific changes, i.e. improvements in strength/power for the CT-group and improvements in speed for the BT-group, are due to the applied configuration of strength, plyometric, and sprint exercises or if they rather indicate a general training response. KW - strength training KW - jump/sprint exercises KW - youth athletes Y1 - 2016 U6 - https://doi.org/10.1055/s-0041-106949 SN - 0932-0555 SN - 1439-1236 VL - 30 SP - 31 EP - 37 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Beurskens, Rainer A1 - Haeger, Matthias A1 - Kliegl, Reinhold A1 - Roecker, Kai A1 - Granacher, Urs T1 - Postural Control in Dual-Task Situations: Does Whole-Body Fatigue Matter? JF - PLoS one N2 - 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. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0147392 SN - 1932-6203 VL - 11 SP - 1379 EP - 1384 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Prieske, Olaf A1 - Mühlbauer, Thomas A1 - Borde, Ron A1 - Gube, M. A1 - Bruhn, S. A1 - Behm, David George A1 - Granacher, Urs T1 - Neuromuscular and athletic performance following core strength training in elite youth soccer: Role of instability JF - Learning and individual differences N2 - 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. KW - Elite sports KW - jumping KW - agility KW - sprint KW - ball speed KW - electromyography Y1 - 2016 U6 - https://doi.org/10.1111/sms.12403 SN - 0905-7188 SN - 1600-0838 VL - 26 SP - 48 EP - 56 PB - Wiley-Blackwell CY - Hoboken ER - TY - GEN A1 - Behm, David George A1 - Mühlbauer, Thomas A1 - Kibele, Armin A1 - Granacher, Urs T1 - 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) T2 - Sports medicine Y1 - 2016 U6 - https://doi.org/10.1007/s40279-016-0497-x SN - 0112-1642 SN - 1179-2035 VL - 46 SP - 451 EP - 451 PB - Springer CY - Northcote ER -