Oxygen deficit: a measure of the anaerobic energy production during intense exercise?

Several findings in studies of whole-body exercise indicate that the energy provided from anaerobic sources during intense whole-body exercise cannot be quantified from oxygen deficit determinations when energy demand for the supramaximal exercise is estimated from a linear relationship between work intensity and energy production during submaximal exercise. It is likely that the energy demand during high-intensity exercise is underestimated by this procedure; these errors are probably greatest for very high power outputs (shorter exercise time to exhaustion). It is clear that further studies are needed to characterize the energy demand during intense exercise before the oxygen deficit can be used as a measure of the anaerobic energy production.