Acute and residual eV ects of vibratory stimulation on explosive strength in elite and amateur athletes

Fourteen elite and 14 amateur athletes were subjected to vibratory stimulation during bilateral biceps curl exercises of explosive strength exertion. The athletes performed two separate series of three sets of exercises in random order. The second set of one series was administered with superimposed vibration of 44 Hz and an acceleration of about 30 m ́s 2 transmitted through the two-arms handle to the arm muscles. The mechanical power of each repetition was measured by the `Power Teach’ instrument. The maximal and mean power values for each set were automatically recorded and shown on the screen. The acute eV ect was evaluated as the diV erence between the mean and peak power output in the second (with vibratory stimulation) and Wrst (without vibratory stimulation) sets. Similarly, the residual eV ect was taken to be the diV erence between the power values of the third (after vibratory stimulation) and the W rst (before vibratory stimulation) sets. The results were subjected to a repeated-measures analysis of variance with group as a between-participants factor. The results showed that exercise mode (with vs without vibratory stimulation) resulted in a signiWcant immediate eV ect for mean power and for maximal power. The factor group (elite vs amateurs) resulted in a signiWcant eV ect for maximal power only. The increase in explosive strength exertion attributed to vibratory stimulation was 30.1 and 29.8 W (10.4% and 10.2%) for maximal and mean power respectively in the elite group, and 20.0 and 25.9 W (7.9% and 10.7%) respectively in the amateur athletes. Vibratory stimulation resulted in an insigniWcant residual eV ect.