Morning vs Evening Exercise for Obesity

(TIMEX Trial)

Overseen By Kristen Bing

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Colorado, Denver

Must not be taking: Appetite suppressants, Antipsychotics, Beta blockers, others

Disqualifiers: Diabetes, Hypertension, Depression, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

128 Participants Needed

Trial Summary

What is the purpose of this trial?

The investigators are doing this study to learn more about how exercising at different times of the day (morning versus evening) affects body weight, sleep, eating patterns, and other factors.

Will I have to stop taking my current medications?

The trial requires that you do not regularly use medications that significantly impact appetite, weight, sleep, or energy metabolism, such as appetite suppressants or certain antidepressants. If you are on such medications, you may need to stop taking them to participate.

What data supports the effectiveness of morning vs evening exercise as a treatment for obesity?

Research shows that both morning and evening exercise can help people with obesity increase their physical activity and improve their sleep quality. Participants in these studies also reported spending less time on sedentary activities like watching TV, which can contribute to weight management. ^{1 2 3 4 5}

Is it safe for humans to exercise in the morning or evening?

Research shows that both morning and evening exercise are generally safe for adults with overweight or obesity, with high adherence and no significant safety concerns reported in the studies. ^{3 4 5 6 7}

How does the timing of exercise impact weight management in obesity treatment?

This treatment is unique because it explores whether exercising in the morning or evening has different effects on weight management for people with obesity. Unlike other treatments that focus solely on exercise intensity or type, this study examines how the timing of exercise might influence energy balance, sleep, and lifestyle behaviors, potentially offering a more personalized approach to weight management. ^{1 2 4 5 8}

Research Team

Vicki Catenacci

Principal Investigator

University of Colorado, Denver

Eligibility Criteria

Adults aged 18-55 with a BMI of 25-40, physically inactive, without chronic diseases like CVD or diabetes. Participants must not be on certain medications, have no recent significant weight changes, and be willing to exercise in the morning or evening as assigned. They should live near the Anschutz Health & Wellness Center and commit to the study's duration.

Inclusion Criteria

I am not planning to get pregnant and use reliable birth control or have had a tubal ligation.

I own a smartphone and agree to use it for meal tracking and assessments.

I am willing and able to follow the study's requirements.

Exclusion Criteria

Night-time shiftwork, rotating work, irregular sleep/wake patterns or other scheduling constraints which may hinder ability to consistently exercise at specific times of the day

My heart's rhythm is irregular or I have a serious heart condition.

Current severe depression or history of severe depression within the previous year, based on Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) criteria for Major Depressive Episode. Score > 18 on Beck Depression Inventory (BDI) will require further assessment by the Study MD to determine if it is appropriate for the subject to participate in the study

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Supervised Exercise

Participants engage in supervised aerobic exercise either in the morning or evening for weight loss

7 months

Regular supervised exercise sessions

Maintenance

Participants continue to exercise at the target of 2000 kcal/week during the randomized AM or PM exercise windows without supervision

6 months

Follow-up

Participants are monitored for changes in body weight, energy intake, and other factors

6 months

Assessments at 3.5, 7, and 13 months

Treatment Details

Interventions

• Evening Exercise
• Morning Exercise

Trial Overview The trial is testing whether exercising in the morning versus evening has different effects on weight loss, sleep quality, eating habits, and other health aspects. Participants will be randomly assigned to one of two groups: those who exercise in the morning and those who exercise in the evening.

Participant Groups

Group I: Morning Exercise (AM) Experimental Treatment 1 Intervention

Participants in this group will be prescribed morning aerobic exercise.

Group II: Evening Exercise (PM) Experimental Treatment 1 Intervention

Participants in this group will be prescribed evening aerobic exercise.

Who Is Running the Clinical Trial?

University of Colorado, Denver

Lead Sponsor

Trials

1,842

Recruited

3,028,000+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Findings from Research

A 12-week moderate exercise training program improved physical fitness, body composition, and subjective sleep quality in overweight and obese adults, regardless of whether the exercise was done in the morning or evening.

While both morning and evening exercise led to similar overall benefits, morning workouts advanced sleep timing, while evening workouts delayed it, suggesting flexibility in scheduling exercise without compromising health outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of morning versus evening exercise training on sleep, physical activity, fitness, fatigue and quality of life in overweight and obese adults. Saidi, O., Colin, E., Rance, M., et al.[2021]

Exercise is a popular strategy for weight loss among adults, but its effectiveness can vary, potentially influenced by the time of day it is performed, with some studies suggesting morning exercise may lead to better weight and fat loss, while others indicate evening exercise could be more effective.

Understanding the impact of exercise timing on weight management could help tailor personalized treatment plans, as it may affect related behaviors like physical activity levels, energy intake, and sleep patterns.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Examining the Role of Exercise Timing in Weight Management: A Review. Blankenship, JM., Rosenberg, RC., Rynders, CA., et al.[2022]

In a study involving 16 healthy participants, evening exercise led to a significantly higher post-exercise energy intake (152 kcal more) compared to morning exercise, despite similar subjective appetite levels before and after workouts.

Morning exercise resulted in greater resting energy expenditure and carbohydrate oxidation, suggesting that while exercise timing affects energy balance, it does not impact immediate exercise performance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Morning Vs. Evening exercise on appetite, energy intake, performance and metabolism, in lean males and females. Mode, WJA., Slater, T., Pinkney, MG., et al.[2023]

A 12-week study involving 100 adults with overweight or obesity showed that both morning and evening exercise significantly increased daily physical activity by about 12-22 minutes compared to baseline.

Participants in both exercise groups also reported improvements in their daily routines, including more sleep (up to 36 minutes) and less time spent on sedentary activities like watching TV or playing video games.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

How do previously inactive individuals restructure their time to 'fit in' morning or evening exercise: a randomized controlled trial. Brooker, PG., Gomersall, SR., King, NA., et al.[2023]

The study successfully randomized 33 adults with overweight and obesity to either morning or evening aerobic exercise, achieving a high retention rate of 94% and adherence of over 90% to the exercise program.

Both morning and evening exercise groups showed changes in total daily energy expenditure (TDEE), with the morning group increasing TDEE more significantly, suggesting that the timing of exercise may influence energy balance and weight management, warranting further investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Morning and Evening Exercise on Energy Balance: A Pilot Study. Creasy, SA., Wayland, L., Panter, SL., et al.[2022]

In a study of 100 inactive adults with overweight or obesity, both morning and evening exercise led to significant weight loss after 12 weeks, with the morning group losing an average of 2.7 kg and the evening group losing 3.1 kg.

Both exercise groups showed improvements in cardiorespiratory fitness, but there was no significant difference in weight loss or fitness gains between morning and evening exercisers, suggesting that the timing of exercise does not impact overall effectiveness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The efficacy of morning versus evening exercise for weight loss: A randomized controlled trial. Brooker, PG., Gomersall, SR., King, NA., et al.[2023]

A systematic review and meta-analysis of 11 studies found that exercising in the morning or evening does not significantly affect systolic or diastolic blood pressure in adults.

Similarly, the timing of exercise (morning vs. evening) showed no significant impact on blood glucose levels, indicating that the time of day may not be a crucial factor for these cardiovascular risk factors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Time of the day of exercise impact on cardiovascular disease risk factors in adults: a systematic review and meta-analysis. Sevilla-Lorente, R., Carneiro-Barrera, A., Molina-Garcia, P., et al.[2023]

In a study involving 50 overweight women, exercising in the morning resulted in significantly higher levels of satiety compared to exercising in the afternoon, suggesting that morning workouts may help control hunger better.

Overall, the timing of moderate-intensity exercise did not significantly affect appetite or energy intake patterns over the following 24 hours, indicating that the benefits of exercise on weight management may not depend on when it is performed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acute Effect of Morning and Afternoon Aerobic Exercise on Appetite of Overweight Women. Alizadeh, Z., Mostafaee, M., Mazaheri, R., et al.[2020]

References

1. England pubmed.ncbi.nlm.nih.gov

Effect of morning versus evening exercise training on sleep, physical activity, fitness, fatigue and quality of life in overweight and obese adults. [2021]

2. Germany pubmed.ncbi.nlm.nih.gov

Examining the Role of Exercise Timing in Weight Management: A Review. [2022]

3. England pubmed.ncbi.nlm.nih.gov

Effects of Morning Vs. Evening exercise on appetite, energy intake, performance and metabolism, in lean males and females. [2023]

4. United States pubmed.ncbi.nlm.nih.gov

How do previously inactive individuals restructure their time to 'fit in' morning or evening exercise: a randomized controlled trial. [2023]

5. Switzerland pubmed.ncbi.nlm.nih.gov

Effect of Morning and Evening Exercise on Energy Balance: A Pilot Study. [2022]

6. United States pubmed.ncbi.nlm.nih.gov

The efficacy of morning versus evening exercise for weight loss: A randomized controlled trial. [2023]

7. Australia pubmed.ncbi.nlm.nih.gov

Time of the day of exercise impact on cardiovascular disease risk factors in adults: a systematic review and meta-analysis. [2023]

8. Netherlands pubmed.ncbi.nlm.nih.gov

Acute Effect of Morning and Afternoon Aerobic Exercise on Appetite of Overweight Women. [2020]