Author(s): BARZYK, P., BIELEKE, M., ASSLÄNDER, L., SCHWENK, M., MORENO, M.M., SCHÜLER, J., GRUBER, M., Institution: UNIVERSITY OF KONSTANZ: UNIVERSITAT KONSTANZ, Country: GERMANY, Abstract-ID: 2138

INTRODUCTION:
Physical inactivity has harmful effects on health and is therefore a major public concern. Recently, we were able to show that high-intensity jump training was able to counteract the detrimental effects of 60 days bedrest on muscle and strength losses as well as on declines in aerobic capacity (Kramer et al. 2017). Within the ProPELL (Promoting Physical Exercise in Lab & Life) research project, we now investigated the effects of eight weeks of high-intensity jump training in non-exercising healthy young adults (Bieleke et al., 2022). We hypothesized to find increases in neuromuscular and aerobic capacity in the training group compared to a non-exercising control group.
METHODS:
Sixty-four young adults (34 female; mean age: 24.5 years, SD 3.5) were randomly assigned to either an eight-week high-intensity jump training or a control group. The training consisted of three weekly sessions of 15-minute high-intensity jump exercises aimed at improving neuromuscular and cardiovascular function. Pre and Post measurements included jump height and peak power during countermovement jumps, maximum isometric strength (leg extension in an isokinetic device), as well as maximum oxygen uptake (VO2peak) using a cycling spiroergometry protocol. We calculated ANOVAs (group * time) to analyze the data.
RESULTS:
Training improved jump height from 36±16 cm to 38±17 cm compared to control (37±16 cm to 37±15 cm; p<.001, d = 0.29). VO2peak increased in both groups without an interaction effect (training group: 33.3±17.4 to 35.4±16.6 ml/min*kg, control: 30.7±15.6 to 31.8 ± 17.6 ml/min*kg; p<.001, d = 0.9). No differences were found for the peak power of countermovement jumps and isometric maximal voluntary contraction during leg extension.
CONCLUSION:
A 15-minute jump training program three times a week increased jump-specific performance in a group of young healthy non-exercising adults. However, we did not find improvements in neuromuscular and cardiorespiratory fitness in this group. Since we have already shown such effects for jump training as a countermeasure to the detrimental effects of physical inactivity on neuromuscular and cardiorespiratory fitness (Kramer et al., 2017), we conclude that the "load" (intensity and volume) of jump training was not high enough in the present study to increase neuromuscular and cardiorespiratory fitness in healthy young adults.

References:
Bieleke, M., Fischer, U., Gruber, M., Kanning, M., Keim, D., Mier, D. Pruessner, J., Schüler, J. (2022). Promoting Physical Exercise in Lab and Life. Identifier DRKS00029727. https://drks.de/search/en/trial/DRKS00029727

Kramer, A., Gollhofer, A., Armbrecht, G., Felsenberg, D., & Gruber, M. (2017). How to prevent the detrimental effects of two months of bed-rest on muscle, bone and cardiovascular system: an RCT. Scientific reports, 7(1), 13177.