The trainability of youths and the existence of periods of accelerated adaptation to training have become key subjects of debate in exercise science. The purpose of this meta-analysis was to characterise youth athletes' adaptability to sprint training across PRE-, MID-, and POST-peak height velocity (PHV) groups. Effect sizes were calculated as a measure of straight-line sprinting performance with studies qualifying based on the following criteria: (a) healthy male athletes who were engaged in organised sports; (b) groups of participants with a mean age between 10 and 18 years; (c) sprint training intervention duration between 4 and 16 weeks. Standardised mean differences showed sprint training to be moderately effective (Effect size=1.01, 95% confidence interval: 0.43-1.59) with adaptive responses being of large and moderate magnitude in the POST- (ES=1.39; 0.32-2.46) and MID- (ES=1.15; 0.40-1.9) PHV groups respectively. A negative effect size was found in the PRE group (ES=-0.18; -1.35-0.99). Youth training practitioners should prescribe sprint training modalities based on biological maturation status. Twice weekly training sessions should comprise up to 16 sprints of around 20 m with a work-to-rest ratio of 1:25 or greater than 90 s.
Moran, J., Sandercock, G., Rumpf, M. C., & Parry, D. A. (2017). Variation in Responses to Sprint Training in Male Youth Athletes: A Meta-analysis. International Journal of Sports Medicine, 38(1), 1-11. https://doi.org/10.1055/s-0042-111439