Vertical and leg stiffness and stretch-shortening cycle changes across maturation during maximal sprint running

► This investigation presented effects of maturation on kinetic and kinematic variables during maximal running velocity in youth. ► Dimensionless vertical stiffness increased significantly with each maturity state. ► Dimensionless leg stiffness was significantly higher in post- compared to mid- and pre-PHV participants. ► Eccentric power was significantly lower in pre- compared to mid- and post-PHV participants. ► Concentric power increased significantly with maturation. ► Furthermore, SSC seemed to contribute to maximal running velocity and the greatest changes appeared at the time of PHV.