MODELING OF RUNNING PERFORMANCES IN HUMANS: COMPARISON OF POWER LAWS AND CRITICAL SPEED

摘要

The concepts of power law and critical speed (S-Crit) have been applied to the analysis of individual running performances. We have analyzed the results of 2 exceptional runners (Nurmi and Gebrselassie) and 11 physical education students (PESs) who performed 3 exhausting running exercises. Power laws can accurately describe the relationships between exhaustion time (t(lim)) and distance (D-lim) or speed (S) (D-lim = k.t(lim)(r) and S = k.t(lim)(r-1)) in elite runners and PES. However, the validity of the application of power laws must be verified for higher values of t(lim) in nonelite runners. Exponent gamma is close to 1 in elite runners and lower in PESs (from 0.625 to 0.872). The value of SCrit was computed from 2 values of t(lim) (3-14 minutes; S-Crit (3-14)) and was expressed as a fraction of maximal aerobic speed (MAS) which was assumed to correspond to the maximal speed that can be sustained over 7 minutes (SCrit (3-14)/S-7min). The individual values of (SCrit (3-14)/S-7min) (0.945 for Gebrselassie, 0.919 for Nurmi, and 0.764 +/- 0.078 in PESs) were linearly correlated with gamma (r > 0.999) and almost equal to gamma (0.952 for Gebrselassie, 0.918 for Nurmi, and 0.779 +/- 0.076 for PESs). The same results were observed when S-Crit was computed for tlim equal to 6-28 minutes (S-Crit (6-28)) and MAS was the maximal velocity sustainable during 14 minutes (S-14min). The fact that g is linearly correlated and almost equal to (SCrit (3-14)/S-7min) or (S-Crit (6-2)/S-14min) suggests that exponent gamma can be considered as an index of aerobic endurance.