Physical inactivity is a major risk factor for noncommunicable diseases and associated mortality. A high-intensity jump training has proven to be efficient in counteracting inactivity related declines in physical function during two months of bed rest. In the present study, we tested the effects of such a training program under real-life conditions. Seventy-five young adults (38 female, 23 ± 3 years) were randomly assigned to either a training or a control group. The training group underwent an 8-week jump training with 15 min of exercises, 3 days per week. Before and after the 8-week period as well as another 8 weeks later we tested jump performance in countermovement jumps (CMJ) and hops, balance performance, maximal isometric strength of leg extensor muscles, stair climb performance, gait analysis, and peak oxygen uptake in a cardiopulmonary exercise test. We observed training specific increases (8% ± 9%) in CMJ height and peak power (5% ± 7%) that were explained by an optimized movement technique. We did not observe generic improvements of balance, strength or functional performance after the training. Peak oxygen uptake showed increases for participants exhibiting low baseline levels. A low-volume high-intensity jump training program was sufficient to increase neuromuscular power and performance in the trained task. Improvements of peak oxygen uptake were restricted to participants with low aerobic capacity baseline levels. These findings suggest that such a program has the potential to induce more generic adaptations and improve the anaerobic and aerobic power of previously non-exercising individuals through a baseline-dependent tailoring of training volume.
Gruber et al. (Thu,) studied this question.