Effects of acute changes in exercise intensity on basal metabolic rate in fit young men

Basal metabolic rate (BMR) was measured by open circuit indirect calorimetry on 3 consecutive days in 25 highly trained men aged 19-32 years. On day 1, the subjects abstained from all forms of exercise beyond normal sedentary activities. On day 2, they increased the level of exercise beyond their usual level of exertion. Measurements of BMR on day 3 showed a significant but small rise. It is suggested that in the prescription of exercise to patients in weight reduction programmes, bouts of vigorous exercise interspersed by one or more days of relative inactivity, will be more effective than a constant level of exercise.