ABSTRACT
Physiological limitation to exercise performance in health and disease is a complex phenomenon. We simplify our approach to this problem by first defining exercise capacity objectively as the
VO2max, or that level of oxygen
consumption obtained as work rate is gradually incremented to the point where
VO2 no longer increases linearly with further increases in work rate.
VO2max often correlates quite well with endurance exercise performance. However, there are exceptions to this tight correspondence; for example, with physical training in which endurance performance times may be dissociated from corresponding changes in
