Resumen:
Running performance depends on maximal oxygen uptake VO↓2max, the ability to sustain a high percentage of VO↓2max for an extended period of time and running economy. Running economy has been studied relatively less than the other factors. Running economy, measured as steady state oxygen uptake VO↓2 at intensities below the ventilatory threshold is the standard method. Extrapolation to a common running speed (268 m/min) or as the VO↓2 required to run a kilometer is the standard method of assessment. Individuals of East African origin may be systematically more economical, although a smaller body size and a thinner lower leg may be the primary factors. Strategies for improving running economy remain to be developed, although it appears that high intensity running may be a common element acting to improve economy.