@article{VoelzkeStutzigThorhaueretal.2012, author = {Voelzke, Mathias and Stutzig, Norman and Thorhauer, Hans-Alexander and Granacher, Urs}, title = {Promoting lower extremity strength in elite volleyball players: Effects of two combined training methods}, series = {JOURNAL OF SCIENCE AND MEDICINE IN SPORT}, volume = {15}, journal = {JOURNAL OF SCIENCE AND MEDICINE IN SPORT}, number = {5}, publisher = {ELSEVIER SCI LTD}, address = {OXFORD}, issn = {1440-2440}, doi = {10.1016/j.jsams.2012.02.004}, pages = {457 -- 462}, year = {2012}, abstract = {Objectives: To compare the impact of short term training with resistance plus plyometric training (RT+P) or electromyostimulation plus plyometric training (EMS+P) on explosive force production in elite volleyball players. Design: Sixteen elite volleyball players of the first German division participated in a training study. Methods: The participants were randomly assigned to either the RT+P training group (n = 8) or the EMS+P training group (n= 8). Both groups participated in a 5-week lower extremity exercise program. Pre and post tests included squat jumps (Si), countermovement jumps (CMJ), and drop jumps (DJ) on a force plate. The three-step reach height (RH) was assessed using a custom-made vertec apparatus. Fifteen m straight and lateral sprint (S15s and S15l) were assessed using photoelectric cells with interims at 5 m and 10 m. Results: RT+P training resulted in significant improvements in Si (+2.3\%) and RH (+0.4\%) performance. The EMS+P training group showed significant increases in performance of CMJ (+3.8\%), DJ (+6.4\%), RH (+1.6\%), S15l (-3.8\%) and after 5 m and 10 m of the S15s (-2.6\%; -0.5\%). The comparison of training-induced changes between the two intervention groups revealed significant differences for the Si (p = 0.023) in favor of RT+P and for the S15s after 5 m (p = 0.006) in favor of EMS+P. Conclusions: The results indicate that RT+P training is effective in promoting jump performances and EMS+P training increases jump, speed and agility performances of elite volleyball players. (c) 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.}, language = {en} } @article{MuehlbauerGollhoferGranacher2012, author = {M{\"u}hlbauer, Thomas and Gollhofer, Albert and Granacher, Urs}, title = {Sex-related effects in strength training during adolescence a pilot study}, series = {Perceptual \& motor skills}, volume = {115}, journal = {Perceptual \& motor skills}, number = {3}, publisher = {Sage Publ.}, address = {Missoula}, issn = {0031-5125}, doi = {10.2466/06.10.30.PMS.115.6.953-968}, pages = {953 -- 968}, year = {2012}, abstract = {The objective was to investigate the effects of high-velocity strength training on isometric strength of the leg extensors and jump height in female and male adolescents. Twenty-eight students (13 boys, 15 girls) ages 16 to 17 years participated in this study and were assigned to either a strength training group or a control group. Strength training was conducted over 8 weeks (2 times per week). Pre- and post-training tests included the measurements of maximal isometric force and rate of force development of the leg extensors as well as countermovement jump height. Both girls (effect size = 1.37) and boys (effect size = 0.61) showed significant improvements in jump height. However, significant increases in maximal isometric force (effect size = 1.85) and rate of force development (effect size = 2.23) were found only in girls. In female and male adolescents, high-velocity strength training is an effective training regimen that produced improvements in countermovement jump height in both sexes but higher gains in maximal isometric force and rate of force development in girls.}, language = {en} } @article{MuehlbauerBesemerWehrleetal.2012, author = {M{\"u}hlbauer, Thomas and Besemer, Carmen and Wehrle, Anja and Gollhofer, Albert and Granacher, Urs}, title = {Relationship between strength, power and balance performance in seniors}, series = {Gerontology}, volume = {58}, journal = {Gerontology}, number = {6}, publisher = {Karger}, address = {Basel}, issn = {0304-324X}, doi = {10.1159/000341614}, pages = {504 -- 512}, year = {2012}, abstract = {Background: Deficits in strength, power and balance represent important intrinsic risk factors for falls in seniors. Objective: The purpose of this study was to investigate the relationship between variables of lower extremity muscle strength/power and balance, assessed under various task conditions. Methods: Twenty-four healthy and physically active older adults (mean age: 70 8 5 years) were tested for their isometric strength (i.e. maximal isometric force of the leg extensors) and muscle power (i.e. countermovement jump height and power) as well as for their steady-state (i.e. unperturbed standing, 10-meter walk), proactive (i.e. Timed Up \& Go test, Functional Reach Test) and reactive (i.e. perturbed standing) balance. Balance tests were conducted under single (i.e. standing or walking alone) and dual task conditions (i.e. standing or walking plus cognitive and motor interference task). Results: Significant positive correlations were found between measures of isometric strength and muscle power of the lower extremities (r values ranged between 0.608 and 0.720, p < 0.01). Hardly any significant associations were found between variables of strength, power and balance (i.e. no significant association in 20 out of 21 cases). Additionally, no significant correlations were found between measures of steady-state, proactive and reactive balance or balance tests performed under single and dual task conditions (all p > 0.05). Conclusion: The predominately nonsignificant correlations between different types of balance imply that balance performance is task specific in healthy and physically active seniors. Further, strength, power and balance as well as balance under single and dual task conditions seem to be independent of each other and may have to be tested and trained complementarily.}, language = {en} } @article{MuehlbauerStuerchlerGranacher2012, author = {M{\"u}hlbauer, Thomas and St{\"u}rchler, M. and Granacher, Urs}, title = {Effects of climbing on core strength and mobility in adults}, series = {International journal of sports medicine}, volume = {33}, journal = {International journal of sports medicine}, number = {6}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0031-1301312}, pages = {445 -- 451}, year = {2012}, abstract = {The objective of this study was to examine the impact of an indoor climbing training and detraining program on core/handgrip strength and trunk mobility in men and women. 28 young sedentary adults participated in this study and were assigned to an intervention (30+/-3 years) or a control (29+/-2 years) group. The intervention group participated in 8 weeks (2 times/week) of indoor climbing training, followed by 8 weeks of detraining. Tests included the measurement of maximal isometric strength (MIS) of the trunk flexors/extensors, the assessment of trunk mobility in the sagittal (SAP) and the coronal (CRP) plane as well as testing of handgrip strength. After training, significant improvements were observed in MIS of the trunk flexors/extensors (similar to 19-22 \%, all p<0.01), in trunk mobility in SAP/CRP (similar to 14-19 \%, all p<0.01), and in handgrip strength (similar to 5 \%, p<0.01). During detraining, MIS (similar to 12-13 \%, all p<0.01) and trunk mobility (similar to 7-10\%, all p<0.01) deteriorated significantly, whereas handgrip strength remained. This indoor climbing training program conducted in sedentary adults proved to be feasible (i.e., attendance rate of 89.4\%) and effective. It is suggested that indoor climbing should be permanently conducted to maintain the observed improvements in core muscle strength and trunk mobility.}, language = {en} }