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 metabolic rate, body composition, dietary intake, and eating behaviour were examined. Participants included 41 overweight, sedentary females aged 25 to 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 three months. Pre- and post-intervention measures included resting energy expenditure (REE), anthropometry (height, weight, 8 skinfolds and 6 girth measurements), a three-day diet record, and the Three-Factor Eating Questionnaire. Results indicated that exercise modality had no effect on REE, dietary intake, or eating behaviour. 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 VO2 max (p=0.012), based on a one-mile walking test. The pattern of weight change of the groups was different (p=0.029) over the three 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. Implications for future studies concerning exercise prescription, exercise adherence, and weight management include preferences for walking as a mode of exercise and the importance of incorporating factors such as group homogeneity, social networking, commitment to a goal, and a leader with a health-related background into an exercise program. Also, it was shown that exercise prevents seasonal weight gain that might otherwise occur in the absence of exercise.Graduate and Postdoctoral StudiesGraduat
