The effects of various intensities of exercise on post-exercise resting metabolic rate

The purpose of this study was to determine the effect of exercise performed at 60% and 80% maximal oxygen uptake on the post-exercise resting metabolic rate when total work was controlled for all subjects. Five females and three males volunteered as subjects. On a non-exercise day, each subject participated in a resting metabolic rate (RMR) test. Following a 30 minute rest period, expired gas was analyzed for O₂ and CO₂ and ventilation volumes were measured. Prior to each exercise bout and following a 4 hour fast, a 30 minute RMR was measured. On two separate exercise days, each subject ran on a treadmill for a distance of 2 miles at 60% and 80% VO₂ max. Following the exercise bout, the post-exercise metabolic rate was measured for 2 hours. Eight 15 minute samples of expired air were collected and analyzed.

No significant differences were observed in the RMR when comparisons were made between the non-exercise day and the pre-exercise RMR prior to performing exercise at 60% and 80% VO₂ max (P = .99). No significant differences were revealed when the 2 hour post-exercise caloric expenditure was compared following exercise at 60% and 80% VO₂ max (P = .81). When total resting caloric expenditure for 2 hours on the non-exercise day was compared to 2 hours post-exercise at 60% and 80% VO₂ max, no significant difference was observed (P = .74). Statistical analysis indicated no significant differences between the pre-exercise and post-exercise RMR within each exercise intensity at any of the eight collection periods. There were also no significant differences in post-exercise RMR at any of the eight collection periods when comparing exercise at 60% and 80% VO₂ max.

It was concluded that EPOC was similar following exercise performed at 60% and 80% VO₂ max and of equal total work. Also, EPOC was of short duration following the two exercise intensities. The post-exercise caloric expenditure was not of significant magnitude to make a significant contribution to weight control.