The energetics of middle-distance running

Summary

In order to assess the relative contribution of aerobic processes to running velocity (v), 27 male athletes were selected on the basis of their middle-distance performances over 800, 1500, 3000 or 5000 m, during the 1987 track season. To be selected for study, the average running velocity$(\bar \upsilon )$ corresponding to their performances had to be superior to 90% of the best French$\bar \upsilon$ of the season. Maximum O₂ consumption$(\dot V_{O_{2{\text{ max}}} } )$ and energy cost of running (C) had been measured within the 2 months preceding the track season, which, together with oxygen consumption at rest$(\dot V_{O_{2{\text{ rest}}} } )$ allowed us to calculate the maximalv that could be sustained under aerobic conditions:$\upsilon _{a max} {\text{ = }}(\dot V_{O_{2{\text{ max}}} } - \dot V_{O_{2{\text{ rest}}} } ) \times {\text{ C}}^{{\text{ - 1}}}$. The treadmill runningv corresponding to a blood lactate of 4 mmol·⁻¹ (v _la4), was also calculated. In the whole group, C was significantly related to height (r=−0.43;P<0.03). Neither C nor$\dot V_{o_{2{\text{ }}max} }$ (with, in this case, the exception of the 3000 m athletes) were correlated to$\bar \upsilon$. On the other hand,v _{a max} was significantly correlated to$\bar \upsilon$ over distances longer than 800 m. These$\bar \upsilon$ were also correlated tov _la4. Howeverv _la4 occurred at 87.5% SD 3.3% ofv _{a max}, this relationship was interpreted as being an expression of the correlation betweenv _{a max} and$\bar \upsilon$. Calculation ofv _{a max} provided a useful means of analysing the performances. At the level of achievement studied,$\bar \upsilon$ sustained over 3000 m corresponded tov _{a max}. The shape of the relationship ofv/v _{a max} as a function of the duration of the event raised the question of a possible change in C as a function of v during middle-distance running competitions.