Fig. 1. Mass-specific stance-averaged support forces vs running speed. (A) stance-averaged force vs running speed in a representative subject; (B) mean stance-averaged support forces for athletic male (M; N=9) and female (F; N=9) subjects (M: y=1.27 + 0.105x; F: y=1.24 + 0.106x). Vertical hashes across the horizontal lines appearing in the upper portion represent the average race velocities of elite male and female specialists at each event distance. y-intercept values of F_g typically do not equal 1.0 because they are extrapolations beyond the range of speeds at which running is possible.