Effect of acute resistance exercise on postexercise energy expenditure and resting metabolic rate.

Two separate experiments were performed to determine the effect of acute resistive exercise on postexercise energy expenditure in male subjects previously trained in resistive exercise. In experiment 1, after measurement of their resting metabolic rate (RMR) at 0700 h and their ingestion of a standardized meal at 0800 h, seven subjects (age range 22-40 yr) beginning at 1400 h completed a 90-min weight-lifting protocol. Postexercise metabolic rate (PEMR) was measured continuously for 2 h after exercise and compared with a preexercise baseline. RMR was measured the following morning 15 h after completion of the workout. In experiment 2, six different men (age range 20-35 yr) completed a similar experimental protocol as well as a control condition on a separate day in which metabolic rate was measured for 2 h after a period of quiet sitting. For both experiments, PEMR remained elevated for the entire 2-h measured recovery period, with the average oxygen consumption for the last 6 min elevated by 11-12%. RMR measured the morning after exercise was 9.4% higher in experiment 1 and 4.7% higher in experiment 2 than on the previous day. In experiment 2, the postabsorptive respiratory exchange ratio was significantly lower the morning after the exercise bout. Strenuous resistive exercise may elevate PEMR for a prolonged period and may enhance postexercise lipid oxidation.