Effects of exercise modality on metabolic rate and body composition

This study was designed to investigate the effects of exercise as a strategy for weight management in overweight women. Specifically, the effects of exercise modality on resting energy expenditure (REE) and body composition [sum of skinfolds and fat-free mass (FFM)] were examined. Participants included 41 overweight, sedentary women aged 25-49 years who had a defined history of dieting. Experimental (n = 26) and control (n = 15) participants were recruited separately. Participants in the experimental group were randomly assigned to either an endurance- or a resistance-training exercise class. Exercise classes designed for a sedentary population were scheduled three times per week for a duration of 3 months. Results indicated that exercise modality had no effect on REE. Exercise, regardless of modality, had a significant effect on body composition (p = 0.0001) as shown by a significant decrease in the sum of skinfolds for the two exercise groups relative to the control group (p < 0.0001). No differences in fat-free mass were observed between groups. Regardless of modality, exercise also resulted in an increased estimated maximum oxygen uptake (VO2max), based on a 1-mile walking test (p = 0.012). The pattern of weight change of the groups was different (p = 0.029) over the 3-month period. Whereas the exercise groups maintained their weight, the control group gained weight (approximately 2.5 kg). Thus, although exercise modality had no effect, the benefits of exercise per se, such as decreased body fat, increased fitness level, and weight maintenance, were observed in this population.