Advanced footwear technology improves sprinting mechanics and performance

Sprint running performances have improved with the use of advanced footwear technology, but the mechanisms responsible are unknown. Here, we tested two hypothesized mechanisms: 1) faster maximal speeds resulting from greater ground force application, and 2) associated contact time decreases, and step length increases that could enable faster late-race velocities. Ten track and five soccer athletes (N=15) completed randomized, linear 130-meter sprint trials in conventional and prototype footwear. The prototypes were highly compliant and resilient in cushioning and stiff in forefoot bending. Instantaneous velocities were recorded with a radar device; contact and aerial times were acquired from ankle-mounted accelerometers throughout; split and final times (60, 100, 130 m) were recorded with dual-beam laser timing gates. Contact times were also determined from 960 Hz video acquired from 10-meter zones between 45 and 80 meters. Performance times for the 130-meter trials were 1.7% shorter in the prototype vs. the conventional spike. Footwear condition differences in velocity were distance-dependent, increasing from a minimum of 0.1% in the first 10 meters, to a maximum of 3.9% at the 130-meter finish line. Video capture zone contact periods were shorter (-1.9%), and estimated stance-averaged ground forces were greater (+1.6%) in the prototype vs. conventional footwear. Progressive gait and velocity effects resulted in relatively large prototype vs. conventional condition differences in the final 30-meter segment for: contact times (-2.5%), aerial times (+6.0%), step lengths (+2.0%), and velocities (+3.0%). We conclude that the prototype footwear enabled gait mechanics that increased both maximal and late-trial sprinting velocities.