The function of neuromuscular system in maximal stretch-shortening cycle exercises: Comparison between power- and endurance-trained athletes.

Differences in neuromuscular function between power athletes (n = 10) and endurance athletes (n = 10) were investigated in six different experimental conditions. In drop jumps and in stretch-shortening cycle (SSC) exercises on the sledge (sledge jumps), the subjects performed about 10 maximal jumps from the optimum dropping height (O) as well as from the dropping height of optimum -40 cm (O - 40) and optimum +40 cm (O + 40). The five to six best jumps were taken for further analysis. In every condition the power group had better physical performance compared to their endurance counterparts. During the pre-activity, the rate of electromyographic (EMG) development of the power athletes was faster. In addition, they had a higher EMG ratio between the eccentric and concentric phases as compared to the endurance athletes. It therefore seems that high and fast pre-activation prepares the muscles to resist the high impact loads during the eccentric phase of SSC. The resulting high tendomuscular stiffness will further enhance the subsequent efficient recoil characteristics during the push-off (concentric) phase.