Examining the Role of Exercise Timing in Weight Management: A Review

Abstract

Many adults cite exercise as a primary strategy for losing weight, yet exercise alone is modestly effective for weight loss and results in variable weight loss responses. It is possible that some of the variability in weight loss may be explained by the time of day that exercise is performed. Few studies have directly compared the effects of exercise performed at different times of the day (i. e., morning versus evening exercise). Results from these existing studies are mixed with some studies demonstrating superior weight and fat mass loss from morning exercise, while other studies have found that evening exercise may be better for weight management. Exercise timing may alter modifiable lifestyle behaviors involved in weight management, such as non-exercise physical activity, energy intake, and sleep. The purpose of this review is to summarize evidence for and against time-of-day dependent effects of exercise on weight management. Although limited, we also review studies that have examined the effect of exercise timing on other lifestyle behaviors linked to body weight regulation. While exercise at any time of day is beneficial for health, understanding whether there is an optimal time of day to exercise may advance personalized treatment paradigms for weight management.

Effect of Morning and Evening Exercise on Energy Balance: A Pilot Study

“…Until recently, the time-of-day exercise is performed and its potential impact on weight loss and energetic compensation has been underappreciated. Accumulating evidence suggests that the timing of exercise may affect changes in weight, body composition, EI, and EE [18]. However, studies to date have significant limitations, including secondary analyses, small sample sizes, limited populations, various exercise stimuli, and limited objective outcome measures [13][14][15][16][17]22,23,34].…”

“…TDEE was measured using the doubly labeled water (DLW) technique. Participants were dosed with ~1.1 g/kg of body weight of 10% atom percent enriched (APE) 18 O-labeled water and ~0.08 g/kg of body weight of 99.8% APE 2 H-labeled water. Urine samples were collected prior to dosing and 4 h, 5 h, 7 days, and 14 days after dosing.…”

“…Both attenuated weight loss and weight loss variability have been attributed to compensatory mechanisms such as reductions in other components of EE and/or increases in energy intake (EI) [1,[6][7][8][9][10][11][12]. The timing (i.e., time of day) of exercise Nutrients 2022, 14, 816 2 of 13 may affect these compensatory responses and the weight loss response [13][14][15][16][17][18][19][20][21][22][23]. In addition, exercise timing may influence factors related to overall adherence and engagement in exercise, thereby influencing body weight [24].…”

“…In addition, these studies lacked objective measures of energy balance. Thus, a prospective, randomized trial is needed to understand the effects of morning versus evening exercise on EE, EI, and weight loss in individuals with overweight and obesity [18]. Prior to a large-scale study, data on the feasibility and acceptability of randomizing adults to morning or evening aerobic exercise are needed.…”

Circadian Synchrony: Sleep, Nutrition, and Physical Activity

“…Surprisingly, studies show that there is no difference in these improvements between people who exercise in the morning and those who exercise in the evening (Alley et al, 2015;Saidi et al, 2021). Notably, there is contrasting evidence regarding the best exercise schedule for weight loss and lowering blood pressure, which could be due to a number of factors discussed hereafter (Brito et al, 2015(Brito et al, , 2019(Brito et al, , 2021Blankenship et al, 2021).…”