Effects of maximal power and the force-velocity profile on sprint acceleration performance according to maturity status and sex.

This study aimed to determine whether maturational and sex-related differences in sprint times were accompanied by changes in relative maximal power (), force-velocity profiles () and optimal sprint distances (). Sprint times and continuous velocity-time data were collected using a radar. Inverse dynamics applied to the centre of mass provided accurate estimations of force-velocity relationship parameters (, , , , ) and technical variables (, ). Somatic maturity was determined from peak height velocity (PHV). Performance increased with maturation in girls and boys ( < 0.001,  = 0.86‒2.78) accompanied by increases in relative from pre to post-PHV ( < 0.011‒0.001,  = 0.98‒5.20). Increases in relative were predominantly due to more velocity-oriented profiles ( < 0.007‒0.001,  = 0.76‒1.41). , and also increased with maturation ( < 0.030‒0.001,  = 0.87‒3.40). increases in girls and boys throughout maturation enabling them to reduce sprint times. Both girls and boys increased through a shift to more velocity-oriented profiles. However, plateaus in and were present from pre-PHV in girls, while boys had slower development from mid-PHV. Improving through increases in and , while maintaining a velocity-oriented profile, will likely benefit youth sprint performance. A specific focus on these parameters is necessary from pre-PHV onwards in girls and from mid-PHV in boys.