What is the appropriate training intensity required to exercise at maximal aerobic power? Certainly not maximum exercise capacity.

Classic experiments in exercise physiology show that work periods of 3-5min with short rest periods 1min provide the optimal stimulus for training maximum aerobic power. When subjects exercised for repeated bouts at 250 Watts for up to 5min, they attained VO2max. Similarly, when the subjects performed a short active rest in between 5min workloads, they lowered their blood lactic acid levels demonstrating that active rest is better for muscle waste removal than total rest.

In another classic experiment from Karlsson et al. (1967), subjects ran for four min at a speed which brought them to exhaustion. In the following days, the same subjects ran at a slower speed but for slightly longer period of time. Despite a lower exercise intensity, subjects achieved VO2max. The conclusion can be drawn therefore that an athlete can train at sub-maximal intensity for periods of 3-5min, with short rest periods, and attain VO2max. This type of training has been shown to be very effective in professional soccer players where 4 * 4min interval training equates to an extra 2km covered on the pitch.

Finally, we believe that it is desirable for athletes’ to experience the sensation of “all-out” efforts. A carefully designed mix of sub-maximal aerobic with high intensity anaerobic training will stimulate the energy systems of both training methods. Furthermore, high intensity maximal or supra-maximal efforts mimic real competition situations more closely than sub-maximal aerobic training making maximal intensity training an important component of any training programme.