Effects of exercise intensity on food consumption in the male rat.

The effects of two different levels of exercise of equal caloric cost on food consumption and body weight changes was investigated in 24 male rats (initial body weight = 378.3 g, SD = 22.3 g). Open circuit spirometry was used for the collection of respiratory gas exchange during running on the treadmill and these data were used to equate two intensities of exercise to the same caloric expenditure. Food consumption was measured 1 hr, and every 4 hr thereafter for 24 hr during 2 alternate weeks of exercise and rest. Results showed that high intensity exercise (16 m . min-1, 10% mill grade) resulted in depressed food consumption and depressed body weight gain than low intensity exercise (5 m . min-1, zero percentage mill grade) of equal caloric expenditure. Both exercise groups had depressed food consumption and rate of body weight change compared to nonexercise animals.