Zusammenfassung

OBJECTIVE: To evaluate the impact of timing of exercise initiation on weight loss within a behavioral weight loss program. METHODS: Adults with overweight/obesity (n=170, 18–55 years, BMI 25–42 kg/m(2), 83.5% female) were enrolled in an 18-month behavioral weight loss program consisting of a reduced-calorie diet, exercise, and group-based support. The standard group (STD) received a supervised exercise program (progressing to 300 minutes/week of moderate-intensity aerobic exercise) during months 0–6. The sequential group (SEQ) was asked to refrain from changing exercise during months 0–6 and received the supervised exercise program during months 7–12. Upon completion of supervised exercise, both groups were instructed to continue 300 minutes/week of moderate-intensity exercise for the study duration. RESULTS: At 6 months, STD exhibited greater reductions in body weight (-8.7±0.7 kg) versus SEQ (-6.9±0.6 kg; P=0.047). Between 6–18 months, STD regained more weight (2.5±0.8, 0.0±0.8 kg; P=0.02). At 18 months, there were no between-group differences in changes in weight (STD −6.9±1.2, SEQ −7.9±1.2 kg), fat mass, lean mass, physical activity, or attrition. CONCLUSION: Both immediate and delayed exercise initiation within a behavioral weight loss program resulted in clinically meaningful weight loss at 18 months. Thus, timing of exercise initiation can be personalized based on patient preference.