Abstract
The aim was to generalize the maximum dynamic output (MDO) hypothesis [i. e., the
muscle power output in vertical jumps (VJ) is maximized when loaded with one’s own
body mass] to variety of VJ. We hypothesized that the subjects’ own body (a) would
be the optimal load for maximizing the power output (i. e., the no-load condition)
and also (b) reveal the maximum benefits of stretch-shortening cycle (SSC). 13 participants
performed the maximum squat and various counter-movement jumps when loaded by approximately
constant external force ranging from −40% to + 40% of their body weight (BW). Regarding
the first hypothesis, the differences in both the peak and mean power recorded under
different load magnitudes revealed maxima close to no-load condition (i. e., from
−3% BW to + 8% BW; R2=0.65–0.96; all P<0.01). Regarding the second hypothesis, the differences in performance between VJ
executed with and without SSC also revealed maxima close to no-load conditions (0–2%
BW), while the same differences in the power output were observed under relatively
low positive loads (14–25% BW; R2=0.56–0.95; all P<0.01). The findings support the concept that maximal power output occurs close to
one’s own body mass during VJ with and without SSC, thereby providing additional support
to MDO hypothesis.
Key words
power - MDO hypothesis - counter-movement - force-velocity relationship