Beyond the growth spurt: Maturity offset, test performance, and squad attainment in youth track and field jumpers

Evidence on maturity–performance associations beyond the growth spurt in youth track and field jumpers remains limited. This study aimed to 1) quantify associations between maturity offset and performance in post-age at peak height velocity jumpers and their age-related variation, and 2) compare maturity timing and performance across squad levels. Retrospective multi-site data from the German Athletics Association were analyzed (791 observations from 581 jumpers; 15.4 ± 1.1 y). Maturity offset was estimated using non-invasive Mirwald equations, and analyses were restricted to post-age at peak height velocity observations. Outcomes included sprints, jumps, power-oriented throwing and 12-min run test. Associations were analyzed using linear mixed-effects models, adjusted for chronological age and sex. Effect estimates were reported as percentage differences from performance means for cross-test comparison and practical interpretation. In a subsample, adjusted mixed models assessed squad-differences. Associations were test-specific. Forward shot throw showed the clearest effect, with improvements of 11.9% (95% CI: 9.2, 14.6) in males and 7.7% (95% CI: 5.3, 10.1) in females per additional year of maturity offset at the centered age, with effects attenuating with age. Sprint and countermovement jump outcomes showed effects close to zero. Endurance and reactive/technical tests showed complex patterns with wide confidence intervals. Estimated maturity timing was 0.18 years (95% CI: 0.03, 0.33) earlier in higher squads, which outperformed lower squads in reactive jumps and selected sprint splits. These findings support maturity-informed, discipline-specific interpretation of test batteries in post-age at peak height velocity jumpers and the value of longitudinal monitoring for equitable talent development.