Maturity and Intermittent Endurance in Male Soccer Players during the Adolescent Growth Spurt: A Longitudinal Study

Abstract

The purpose of the study was to investigate differences in intermittent endurance between early and late maturing junior soccer players using longitudinal data during the adolescent growth spurt. Twenty-nine pubescent male soccer players aged 12.9 ± 0.2 years at the first measurement were classified into three groups (Late, Average, and Early groups) according to their maturity status, which was determined by their relative peak height velocity age. The Yo-Yo intermittent recovery level 2 ( Yo-Yo IR2; intermittent endurance), vertical jump, and five-step jump tests (leg muscle power) as well as measurements of VO₂max (aerobic fitness) and thigh muscle volume were performed on six occasions at half-year intervals. A two-way repeated ANOVA revealed a significant interaction between the maturity status and Yo- Yo IR2 results. The Yo-Yo IR2 results correlated significantly with those obtained from the vertical jump and five-step jump tests from 12.9 to 14.3 years of age (r = 0.40-0.76) as well as with those for VO₂max from 14.8 to 15.4 years of age (r = 0.50-0.58). The difference in the Yo- Yo IR2 between Early and Late groups was the largest at 13.4 years which was in the middle of the adolescent growth spurt. However, this large difference was observed temporally and disappeared after the spurt period. These results revealed the later development of leg muscle power in late maturing players and a change in the determinants of intermittent endurance during adolescence. Intermittent endurance is limited mainly by leg muscle power that develops simultaneously with maturation during the spurt period. After the spurt period, however, aerobic fitness which is not as strongly related to the stage of maturity comes to contribute to intermittent endurance.