Comparison of morning vs evening exercise on weight loss and related health behaviors in individuals with overweight or obesity: study protocol for a 56-week randomized controlled trial (TIMEX)
摘要
Aerobic exercise is recommended for weight management. Recent evidence suggests that there may be time-dependent differences in how exercise affects body weight and energy balance regulation. The primary purpose of this study is to determine the effect of morning versus evening aerobic exercise on changes in body composition and components of energy balance in adults with overweight and obesity.
MethodsThe Timing Intervention of Morning versus Evening EXercise (TIMEX) study is a two-arm, 56-week, block randomized (1:1) aerobic exercise intervention. One hundred twenty-eight adults with overweight and obesity will be randomized to engage in morning (AM-Ex, 06:00–10:00) or evening (PM-Ex, 15:00–19:00) moderate- to-vigorous intensity aerobic exercise progressing to 2000 kcal/week of energy expenditure. The primary outcome is change in body weight at 7 months. Secondary outcomes include changes in body composition, energy intake, hunger and eating behaviors, energy expenditure, and physical activity behaviors at 7 and 13 months.
DiscussionAerobic exercise elicits modest weight loss; however, there is substantial inter-individual variability in the weight loss response with some individuals losing significant amounts of weight and others gaining weight. The time of day exercise is performed may contribute to this weight loss variability. Understanding how the time of day of exercise affects weight loss and components of energy balance may lead to tailored exercise interventions that enhance weight loss. The TIMEX study will determine the effect of a guidelines-based dose of aerobic exercise completed in the morning versus the evening on weight loss, energy intake, and energy expenditure.
Trial registrationClinicalTrials.gov NCT02153252. Registered on 12/10/2021.