Acute Effect of Morning and Afternoon Aerobic Exercise on Appetite of Overweight Women

The impact of exercise on food-related inhibitory control- do calories, time of day, and BMI matter? Evidence from an event-related potential (ERP) study

A growing body of research suggests exercise improves inhibitory control functions. We tested if exercise-related inhibitory control benefits extend to food-related inhibitory control and differ by calorie content, time of day, and weight status. One hundred thirty-eight individuals were pseudo-randomly assigned to a morning or evening group. Each subject participated in two lab sessions where they completed questionnaires (rest session) or walked on a treadmill at 3.8mph (exercise session) for 45 min. After each session, participants completed both a high-calorie and low-calorie go/no-go task while N2 and P3 event-related potentials (ERP), both neural indicators of inhibitory control, were measured. Participants also rated food images for valence and arousal. While N2 and P3 difference amplitudes were larger to high-calorie than low-calorie foods, neither exercise nor time of day affected results. Individuals had faster response times after exercise without decreases in accuracy. Arousal and valence for high-calorie foods were lower after exercise and lower for all foods after morning compared to evening exercise. In a subset of individuals with obesity and normal-weight individuals, individuals with obesity had larger N2 difference amplitudes after morning exercise, while normal-weight individuals had larger P3 difference amplitudes to high-calorie foods after exercise. Results suggest moderate exercise did not affect food-related inhibitory control generally, although morning exercise may be beneficial in improving early recruitment of food-related inhibitory control in individuals with obesity. Moderate exercise, particularly in the morning, may also help manage increased attention allocated to food.

Effects of Morning Vs. Evening exercise on appetite, energy intake, performance and metabolism, in lean males and females

Exercise is an important component of a weight management strategy. However, little is known about whether circadian variations in physiological and behavioural processes can influence the appetite and energy balance responses to exercise performed at different times of the day. This study compared the effects of morning and evening exercise on appetite, post-exercise energy intake, and voluntary performance. In randomised, counterbalanced order, 16 healthy males and females (n = 8 each) completed two trials, performing morning exercise at 10:30 (AMEx) or evening exercise at 18:30 (PMEx). Exercise consisted of 30 min steady-state cycling (60% V˙ O_2peak), and a 15-min performance test. A standardised meal (543 ± 86 kcal) was consumed 2-h before exercise and ad-libitum energy intake was assessed 15 min after exercise, with subjective appetite measured throughout. Absolute ad-libitum energy intake was 152 ± 126 kcal greater during PMEx (P < 0.001), but there was no differences in subjective appetite between trials immediately pre-exercise, or immediately before the post-exercise meal (P ≥ 0.060). Resting energy expenditure (P < 0.01) and carbohydrate oxidation (P < 0.05) were greater during AMEx, but there were no differences in substrate oxidation or energy expenditure during exercise (P ≥ 0.155). Exercise performance was not different between trials (P = 0.628). In conclusion, acute morning and evening exercise prompt similar appetite responses, but post-exercise ad-libitum energy intake is greater following evening exercise. These findings demonstrate discordant responses between subjective appetite and ad-libitum energy intake but suggest that exercise might offset circadian variations in appetite. Longer-term studies are required to determine how exercise timing affects adherence and weight management outcomes to exercise interventions. TRIAL REGISTRATION: NCT04742530, February 8, 2021.

Impact of exercise timing on perceived appetite and food reward in early and late chronotypes: An exploratory study in a male Saudi sample

There is very limited evidence on the influence of diurnal exercise timing on appetite control, and none on food reward or how an individual's chronotype could moderate such effects. We examined the impact of acute exercise timing on perceived appetite and food reward in young Saudi adults with early or late chronotypes. Forty-five young adults (23 ± 4 years; BMI = 25.1 ± 4.0 kg/m²) completed the Morningness-Eveningness Questionnaire (MEQ) and were divided into early (score = 59 ± 5) or late (score = 41 ± 6) chronotypes. Participants attended the laboratory after ≥4 h fast on two occasions for an AM (8:00-10:00) and PM (17:00-19:00) 30-min moderate-intensity cycling bout in a randomized counterbalanced order. Appetite ratings and food reward (Arab Leeds Food Preference Questionnaire) were measured before and after exercise. An acute exercise-induced decrease in hunger was found, which appeared to be dependent upon diurnal timing and chronotype, with hunger being more suppressed after AM exercise in the early chronotypes and after PM exercise in the late chronotypes. There was greater wanting for low-fat sweet foods after AM exercise relative to PM exercise, whereas there was greater wanting for high-fat sweet food and sweet relative to savoury food after PM exercise compared to AM exercise. These preliminary findings suggest that diurnal timing of exercise impacts food preferences, and that chronotype may influence the appetite response to an exercise bout at different times of day.

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

The purpose of this study was to evaluate the feasibility and acceptability of randomizing adults with overweight and obesity (BMI 25-40 kg/m2) to morning (06:00-10:00) or evening (15:00-19:00) aerobic exercise. Participants completed four exercise sessions per week in the morning (AM, n = 18) or evening (PM, n = 15). The exercise program was 15 weeks and progressed from 70 to 80% heart rate maximum and 750-2000 kcal/week. Bodyweight, body composition, total daily energy expenditure (TDEE), energy intake (EI), sleep, sedentary behavior (SB), non-exercise physical activity (NEPA), and maximal aerobic capacity were assessed at baseline and week 15. Study retention was 94% and adherence to the supervised exercise program was ≥90% in both groups. Weight change was -0.9 ± 2.8 kg and -1.4 ± 2.3 kg in AM and PM, respectively. AM and PM increased TDEE (AM: 222 ± 399 kcal/day, PM: 90 ± 150 kcal/day). EI increased in AM (99 ± 198 kcal/day) and decreased in PM (-21 ± 156 kcal/day) across the intervention. It is feasible to randomize adults with overweight and obesity to morning or evening aerobic exercise with high levels of adherence. Future trials are needed to understand how the timing of exercise affects energy balance and body weight regulation.

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

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.

The impact of circadian timing on energy balance: an extension of the energy balance model

A significant proportion of the population is classified as having overweight or obesity. One framework which has attempted to explain biobehavioral mechanisms influencing the development of overweight and obesity is the energy balance model. According to this model, the body continually attempts to balance energy intake with energy expenditure. When energy intake and energy expenditure become imbalanced, there is an increase in homeostatic and allostatic pressure, generally to either increase energy intake or decrease energy expenditure, so as to restore energy homeostasis.Recent research has indicated that circadian aspects of energy intake and energy expenditure may influence energy balance. This paper provides a narrative review of existing evidence of the role of circadian timing on components of energy balance. Research on the timing of food intake, physical activity, and sleep indicates that unhealthy timing is likely to increase risk of weight gain. Public health guidelines focus on how much individuals eat and sleep, what foods are consumed, and the type and frequency of exercise, but the field of circadian science has begun to demonstrate that when these behaviors occur may also influence overweight and obesity prevention and treatment efforts.

Effects of diurnal exercise timing on appetite, energy intake and body composition: A parallel randomized trial

OBJECTIVE

To determine the effect of diurnal exercise timing on appetite, energy intake and body composition in individuals with overweight or obesity.

METHODS

Forty sedentary, individuals with overweight or obesity (17 males, 23 females; age: 51 ± 13 years; BMI: 30.9 ± 4.2 kg/m²) were randomly allocated to complete a 12-week supervised multi-modal exercise training program performed either in the morning (amEX) or evening (pmEX). Outcome measures included appetite in response to a standardised test meal, daily energy intake (EI), body weight and body composition. Measures of dietary behaviour were assessed at baseline and post-intervention, along with habitual physical activity, sleep quality and sleep quantity. Significance was set at p ≤ .05 and Hedge's g effect sizes were calculated.

RESULTS

Regardless of timing, exercise training increased perceived fullness (AUC; g = 0.82-1.67; both p < .01), decreased daily EI (g = 0.73-0.93; both p < .01) and body-fat (g = 0.29-0.32; both p <. 01). The timing of exercise did not change the daily EI or body-fat response to training (all p ≥ .27), however, perceived fullness increased in the amEX group (p ≤ .01). DISINHIBITION: (g = 0.35-1.95; p ≤ .01) and Hunger (g = 0.05-0.4; p = .02) behaviours decreased following exercise training, with Disinhibition demonstrating greater improvements in the pmEX group (p = .01). Objective and subjective sleep quantity increased with training (all p ≤ .01), but sleep quality was not reported to change.

CONCLUSIONS

Multi-modal exercise training improved body composition and some appetite outcomes, although changes were inconsistent and largely independent of exercise-timing. In the absence of dietary manipulation, the effect of diurnal exercise timing on appetite and body composition appear trivial compared to the overall benefits of exercise participation.

Assessment of acute aerobic exercise in the morning versus evening on asprosin, spexin, lipocalin-2, and insulin level in overweight/obese versus normal weight adult men

The aim of this study was to examine the acute effect of aerobic exercise when performed in the morning and evening on obesity-related hormones of asprosin, spexin, lipocalin-2, and insulin in normal weight (NW) and overweight/obese (OW/OO) adults. A total of 20 adult male individuals (10 NW and 10 OW/OO) volunteered their participation. Both groups were subjected to an aerobic exercise protocol in moderate intensity (heart rate reserve of 55-59%) for 30 min at two different time periods of the day (morning: 08:00-10:00 h, evening: 20.00-22.00 h) at least 3 d apart. BeBis analysis revealed the OW/OO group consumed significantly less energy (1781.59 ± 410.71 kcal) as compared with NW group (2380.28 ± 445.50 kcal) before the evening exercise (about 3 d) (p <.05). As compared with the NW group, basal serum asprosin, insulin, and lipocalin-2 hormone levels were higher in the OW/OO group, and serum spexin level was lower in OW/OO group (p <.05). Body temperature significantly increased after morning and evening aerobic exercise in both groups. The increase in body temperature was significantly higher after the evening exercise in the OW/OO group compared to the NW group (p <.05). Significant decrease in serum asprosin lipocalin-2, and insulin levels was observed in both groups after exercise (p <.05). Evening aerobic exercise more greatly decreased serum asprosin, lipocalin-2, and insulin level in the OW/OO group as compared with the NW group (p <.05). In conclusion, it is thought that negative energy balance caused by psychological energy restriction and evening aerobic exercise, which leads to a further increase in body temperature, triggers greater decrease of orexigenic signals (suppression of appetite), and is more effective in the development of adipose tissue inflammation and insulin sensitivity, especially in OW/OO group.

Appetite control and exercise: Does the timing of exercise play a role?

The prevention and management of chronic diseases, particularly overweight and obesity, relies on multidisciplinary strategies mainly combining dietary approaches with physical activity. Recently, the timing of exercise (time of the day as well as delay/position relative to a meal) has been suggested as an important parameter to consider when prescribing physical activity. Some studies have for instance shown the interest of the timing of exercise on the glycemia, sleep and body composition regulation. However, the impact of exercise-timing on appetite control and energy intake remains unclear. This is why, the present paper questions whether physical exercise, depending on its timing during the day and related to a meal, can affect energy intake, appetite sensations and food reward. Although evidences remain actually limited, exercising during the morning; and particularly close to lunch, might have a better impact on overall energy balance through reduced subsequent energy intake, without leading to compensatory intakes at the following meals. Importantly, dealing with the timing of exercise to optimize energy balance (and affect energy intake and appetite) does not only require to consider its time during the day (morning vs. afternoon or evening), but also and maybe mainly its order/position (pre vs. post) and delay regarding meals. While the actual literature remains limited in this area, the present paper tends to highlight the importance of considering the timing of exercise to optimize our impact on the overall energy balance, and to encourage the elaboration of further studies to better understand and determine the potential effect of this timing of exercise, in order to find the best combination between the different exercise characteristics, intensity, duration, modality, to empower these effects.

Impact of Exercise Timing on Chemosensory Response, Appetite, and Energy Intake in Lean Males

BACKGROUND

High-intensity exercise can have an anorectic impact, leading to negative energy balance. Several studies have reported that the practice of physical activity could also cause a shift in perceptions and preferences, causing a change in food intakes.

OBJECTIVE

This study aimed to question to what extent the timing of exercise in relation to a meal could have an impact on olfaction and gustation, appetite, and food choices.

METHODS

Twelve males aged 25 (4) years with a body mass index of 22.4 (2.0) kg/m2 attended two experimental visits in a counterbalanced fashion. The participants consumed a standardized breakfast between 7:00 and 7:30 a.m. and were subjected to smell and taste tests upon arrival at the laboratory (8:30 a.m.). In the EX9:40 visit, the participants performed a 30-min exercise session (70% of maximum oxygen uptake) at 9:40 a.m., followed by a 90-min sedentary break. In EX10:30, the participants first took part in the 90-min sedentary break and then performed the 30-min exercise session at 10:30 a.m. Taste and smell tests were performed again at 11:40 a.m., immediately followed by an ad libitum buffet-style meal. Visual analog scales were used to report appetite sensations during the session and satiety quotients around the lunch.

RESULTS

There was no difference in energy intakes between the EX9:40 (596 [302] kcal) and EX10:30 (682 [263] kcal) conditions (p = .459). There was no condition effect for the taste and smell sensations (all ps > .05), appetite sensation, or satiety quotients around the meal (all ps > .05).

CONCLUSION

Exercise timing in the morning had no effect on taste and smell perceptions, appetite sensations, or energy intakes.

The effects of exercise session timing on weight loss and components of energy balance: midwest exercise trial 2

Background/objectives

Circadian physiology has been linked to body weight regulation and obesity. To date, few studies have assessed the association between exercise timing and weight related outcomes. The aim of this secondary analysis was to explore the impact of exercise timing (i.e., 24 h clock time of exercise session) on weight loss and components of energy balance.

Subjects/methods

Overweight/obese (BMI 25.0–39.9 kg/m²), physically inactive, young adults (~51% female) completed a 10-month supervised exercise program (400 or 600 kcal/session for 5 days/week) or served as non-exercise controls (CON). Participants were categorized based on the time of day in which they completed exercise sessions (Early-Ex: >50% of sessions completed between 7:00 and 11:59 am; (n = 21), Late-Ex: >50% of sessions completed between 3:00 and 7:00 pm; (n = 25), Sporadic-Ex: <50% of sessions completed in any time category; (n = 24), and CON; (n = 18)). Body weight, energy intake (EI; digital photography), and non-exercise physical activity (NEPA; accelerometer) were assessed at baseline, 3.5, 7, and 10 months. Total daily energy expenditure (TDEE; doubly labeled water), was assessed at baseline and 10 months.

Results

At month 10, weight loss was significantly greater in both Early-EX (−7.2 ± 1.2%; p < 0.001) and Sporadic-EX (− 5.5 ± 1.2%; p = 0.01) vs CON (+0.5 ± 1.0%), and Early-EX vs Late-EX (−2.1 ± 1.0%; p < 0.001). There were no between group differences for change in TDEE, EI, and non-exercise energy expenditure (P > 0.05). A significant group × time interaction (p = 0.02) was observed for NEPA (counts/min), however, after adjusting for multiple comparisons, group effects were no longer significant.

Conclusions

Despite minimal differences in components of energy balance, Early-EX lost significantly more weight compared with Late-Ex. Although the mechanisms are unclear, the timing of exercise may be important for body weight regulation.

Comparison between the effect of 6 weeks of morning or evening aerobic exercise on appetite and anthropometric indices: a randomized controlled trial

Several studies have shown that exercise is directly related to creating negative energy balance and changes in appetite. However, few studies have examined the effect of exercise time during the day on these factors. The aim of the present study was to demonstrate the effect of 6 weeks of morning and evening aerobic exercise on appetite and anthropometric indices. A total of 48 overweight females were recruited to this clinical trial. By the time of exercise, they were divided into two groups (morning or evening) and performed 6 weeks of exercise with a target heart rate on the ventilatory threshold. Appetite change, calorie intake and anthropometric indices were assessed. Consistent changes in appetite scores were not found during the 6 weeks (P > 0.05). Calorie consumption of the morning group decreased significantly more than that of the evening group (P = 0.02) during the 6 weeks. In addition, significant changes in body weight, body mass index, abdominal skin fold thickness and abdominal circumference were seen in the morning group. It appears that moderate- to high-intensity aerobic exercise in the morning could be considered a more effective programme than evening exercise on appetite control, calorie intake and weight loss in inactive overweight women. However, the limitations of the study, such as short-term duration, should be noticed.