Effects of exercise-training on the thermic effect of food and body fatness of adult women

Abstract

Resting metabolic rate (RMR), thermic effect of food (TEF), aerobic capacity (VO 2max), body fat, and food intake were measured in 10 healthy women before and after a 10 week graded exercise program of jogging. Pretraining TEF was a linear function of VO 2max. Following exercise training, the women showed a significant increase (20%) in VO 2max and loss (10.4%) of body fat; body weight did not change. Fat loss was directly related to changes in VO 2max and RMR. The women showed a wide variation of changes in RMR (−21 to +2%) and TEF (−32 to +66%) from their pretraining levels. The changes in RMR and TEF were significantly positively correlated with improvements in VO 2max. Analyses using multiple regression techniques, indicated that the changes in RMR and TEF accounted for 96.2% of the total variation in the changes of VO 2max. Analyses of food intake indicated that diet composition (but not caloric intake) was highly related to the changes in VO 2max, RMR, TEF and body fatness. Present results support further our hypothesis, that VO 2max is an important physiological index of dietary thermogenesis and fat loss of individuals of normal body weight and fatness. Possible nutritional and physiological factors that may explain the wide variation in RMR and TEF of the women are discussed.