By purchasing this content you agree and accept the terms and conditions
The purpose of this investigation was to examine the influence of running velocity, stride characteristics, training background, gender, and caliber of a runner on the changes in ground contact time during a 400-m run. Thirteen male and 4 female sprinters ran a 400-m time trial on the track, and 8 male sprinters and 6 male endurance athletes ran a simulated 400-m trial at constant velocity on the treadmill. A special shoe insert was placed in the track spike to determine contact time, and a video camera was used to determine split times for each 40 m. Two threshold points were identified during the 400-m run, with the first occurring when the running velocity began to decrease. The threshold points were affected by the individual running strategy and reflected fatigue-induced changes in the running velocity; they also were independent of gender, training background, and caliber of an athlete.
Ari Nummela and Heikki Rusko are with the Research Institute for Olympic Sports, Rautpohjankatu 6, FIN-40700 Jyvӓskyiӓ, Finland. James Stray-Gundersen is with Baylor/University of Texas Southwestern Sports Science and Research Center, 411 North Washington, Suite 3000, Dallas, TX 75246.