This study examined the effects of the SpeedMaker device versus a control condition on jump performance and muscle activity (MA). Female collegiate lacrosse and track athletes (n=16) performed three 45 m sprints at increasing intensities of 80, 90, and 100% of maximum sprint speed either wearing the device or in a control condition. Two minutes after the sprints, athletes performed three maximal countermovement jumps (CMJ) without the device. Variables examined were flight time (FT), peak ground reaction force (PGRF), rate of force development (RFD) and MA during the CMJ. Compared to the control condition, the SpeedMaker device displayed higher PGRF and RFD (p \u3c 0.05). There was no difference (p \u3e 0.05) for FT or for MA. The SpeedMaker device enhanced some factors affecting jump flight time, but ultimately did not increase flight time or muscle activity
