A new method to normalise exercise intensity

Abstract

Exercise intensity has traditionally been described, prescribed and normalised as a fraction (%) of the maximal oxygen uptake (VO2max). We hypothesised that the extent of inter-subject variability in the physiological responses to exercise would be greater when work rates were prescribed using % VO2max as compared to % delta (), a method of normalising exercise intensity in which both the gas exchange threshold (GET) and the VO2max are considered. 9 men completed a ramp incremental test on a cycle ergometer to establish the GET and VO2max. Subsequently, subjects completed 6 constant-work-rate exercise bouts at intensities corresponding to: 50%, 70% and 90% VO2max; and 60% GET, 40% (that is, 40% of the difference between the GET and VO2max) and 80% . For all bouts, exercise was continued for 20min or until task failure if this occurred sooner. When exercise was prescribed using the % concept, there were significant reductions in the inter-subject variability in pulmonary gas exchange, blood lactate accumulation, heart rate, and ratings of perceived exertion (all P<0.05). In conclusion, the % concept resulted in more consistent inter-subject physiological responses to constant-work-rate exercise and should be used in preference to % VO2max to more effectively normalise exercise intensity. © Georg Thieme Verlag KG Stuttgart - New York.