Stretch-Shortening-Cycle Performance of Active and Inactive Children and Adolescents

In this investigation, the stretch-shortening cycle (SSC) performance of untrained male children and juveniles was measured and compared to that of soccer-playing children of equivalent age. The subjects were between 9 and 18 years old. Five age cohorts were formed. Every cohort consisted of two adjacent ages. The groups including the soccer-playing children was again divided in subgroups of subjects who only play soccer and participants who performed an additional strength training program. SSC performance capacity was tested with drop jumps from different heights (16,24,32,40 and 48cm), squat jumps, countermovement jumps and a 30-m sprint. Nearly all comparisons between untrained and soccer-playing subjects showed a significant (p < 0.05) difference. Furthermore, an additional strength training program led to a significantly greater SSC performance capacity in most of the tests compared to just playing soccer. Finally it should be pointed out that the SSC performance of the untrained children was very low especially in the drop jump. Just playing soccer increased the SSC performance in children significantly. Implementing a strength training program into soccer training might have a positive effect on SSC performance even in the youngest cohort (9-10 yrs).