Morning vs Evening Exercise for Prediabetes

(TExIS Trial)

Overseen By Seth Creasy, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Colorado, Denver

Must not be taking: Oral steroids, Metformin, GLP1 agonists

Disqualifiers: Cardiovascular disease, Diabetes, CKD, others

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

Compensation: Varies

Number of Visits: 9

25 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how exercising in the morning versus the evening affects blood sugar levels and other health factors in people with prediabetes. Participants will engage in both morning and evening exercise routines to determine which better aids glucose metabolism (how the body uses sugar) and overall health. The trial suits women with prediabetes who have not been exercising much and have a BMI between 30 and 40. As an unphased trial, it offers participants the chance to contribute to valuable research that could enhance exercise recommendations for people with prediabetes.

Will I have to stop taking my current medications?

The trial requires that you do not use certain medications that affect insulin sensitivity, like oral steroids, metformin, or GLP1 receptor agonists. If you are taking these, you would need to stop before participating.

What prior data suggests that this exercise protocol is safe for prediabetes?

Previous studies have shown that exercise is very safe for people with prediabetes. Regular aerobic activities, like walking or jogging, help muscles use insulin more effectively, which is crucial for controlling blood sugar levels. Research indicates that exercising in the morning or evening is generally well-tolerated and aids in managing blood sugar.

For morning exercise, studies found that just two weeks of activity can help reverse prediabetes in some individuals. These exercises typically don't cause serious issues, but it's important to monitor how the body feels. Some reports suggest that evening exercise might be even more beneficial for energy use.

Overall, exercise is a safe and effective way to manage prediabetes. Always pay attention to the body's signals and consult a doctor if there are any concerns before starting a new exercise routine. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about exploring the timing of exercise for managing prediabetes because it could unlock new ways to control blood sugar levels without the need for medications. Most standard treatments for prediabetes involve lifestyle changes like diet modification and increased physical activity, but this trial specifically examines whether exercising in the morning or evening has different effects on glucose metabolism. This approach is unique because it looks at the body's natural rhythms to optimize the benefits of exercise, potentially offering a simple, non-invasive strategy to improve health outcomes for people with prediabetes.

What evidence suggests that morning and evening exercise could be effective for prediabetes?

Research has shown that exercise can greatly improve blood sugar levels in people with prediabetes. This trial will have participants engage in either morning or evening exercise to determine which is more effective. Morning exercise positively affects blood sugar levels, as muscles use sugar more efficiently, potentially lowering blood sugar. Meanwhile, evening exercise might also be effective; some studies suggest it could be even better for maintaining stable blood sugar, as it has been linked to a significant drop in levels. Both morning and evening workouts can help manage blood sugar, but the best time might vary for each person. ^{1 3 6 7 8}

Are You a Good Fit for This Trial?

This trial is for adults with prediabetes, which may include those who are overweight and lead a sedentary lifestyle. Participants should be willing to undergo various tests including blood draws, EKGs, x-rays, and wear monitors. They must follow a specific diet during the study and complete morning and evening exercise sessions.

Inclusion Criteria

Not currently pregnant or lactating, not pregnant within the past 6 months or planning to become pregnant in the next 6 months.

Weight stable (weight change < 5kg in past 3 months)

I am between 20 and 40 years old.

Exclusion Criteria

Current or recent (within 1 month) zero or very low carbohydrate diet (< 10% daily calories from carbohydrates)

Diastolic blood pressure > 100 mmHg, systolic blood pressure > 160 mmHg, or resting heart rate > 100 bpm

I have a history or symptoms of heart disease or heart failure.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

2 visits (in-person)

Baseline

Participants complete a baseline condition of no exercise with dietary control and monitoring

3 days

1 visit (in-person)

Morning Exercise

Participants perform morning exercise for 3 consecutive days with dietary control and monitoring

3 days

3 visits (in-person)

Evening Exercise

Participants perform evening exercise for 3 consecutive days with dietary control and monitoring

3 days

3 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after exercise conditions

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Morning and Evening Exercise

Trial Overview The study investigates how exercising in the morning versus the evening affects glucose metabolism in people with prediabetes. It involves no-exercise baseline measurements followed by three consecutive days of either AM or PM exercise, separated by 3-4 weeks.

How Is the Trial Designed?

Group I: Crossover - PM first Experimental Treatment 2 Interventions

Crossover design with PM exercise first

Group II: Crossover - AM first Experimental Treatment 2 Interventions

Crossover design with AM exercise first

Who Is Running the Clinical Trial?

University of Colorado, Denver

Lead Sponsor

Trials

1,842

Recruited

3,028,000+

Published Research Related to This Trial

In a study involving 11 men with type 2 diabetes, afternoon high-intensity interval training (HIIT) significantly reduced blood glucose levels compared to morning HIIT, which actually increased glucose levels after exercise.

The findings suggest that the timing of exercise is crucial for managing blood glucose in type 2 diabetes, with afternoon sessions being more effective, highlighting the need for further research on longer training regimens.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Afternoon exercise is more efficacious than morning exercise at improving blood glucose levels in individuals with type 2 diabetes: a randomised crossover trial. Savikj, M., Gabriel, BM., Alm, PS., et al.[2020]

Exercise timing can influence the skeletal muscle clock, which is crucial for regulating metabolism and may help improve conditions like type 2 diabetes.

Disruptions in the skeletal muscle clock are linked to an increased risk of type 2 diabetes, suggesting that strategically timed exercise could serve as a therapeutic approach to enhance metabolic health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Time for Exercise? Exercise and Its Influence on the Skeletal Muscle Clock. Martin, RA., Esser, KA.[2023]

A pilot study involving non-diabetic individuals and a subject with Insulin Dependent Diabetes Mellitus (IDDM) showed that exercising in the morning led to a rapid decrease in blood glucose levels for non-diabetics, while evening exercise resulted in less decline and quicker recovery.

For the diabetic subject, morning exercise did not lower glucose levels and instead caused an increase after 40 minutes, suggesting that the timing of exercise may significantly impact glucose control in individuals with diabetes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Chronobiology of exercise: the influence of scheduling upon glycemic responses of control and of subjects with diabetes mellitus. Cardoso, SS., Feuers, RJ., Tsai, TH., et al.[2011]

Postmeal exercise is more effective than premeal exercise for managing blood sugar levels in diabetes patients, as it allows the body to use glucose from the meal as fuel during physical activity.

The optimal time to start moderate-intensity exercise is about 30 minutes after a meal, as this timing helps to lower the peak in blood sugar levels that occurs after eating.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Why exercise before breakfast may not be for diabetes patients. Chacko, E.[2015]

In a 12-week exercise program involving 32 adult males at risk for type 2 diabetes, afternoon exercise training resulted in significantly better improvements in insulin sensitivity and metabolic health compared to morning training.

Participants who exercised in the afternoon showed greater reductions in fasting plasma glucose levels, fat mass, and improved exercise performance, suggesting that the timing of exercise can influence its effectiveness for metabolic health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exercise training elicits superior metabolic effects when performed in the afternoon compared to morning in metabolically compromised humans. Mancilla, R., Brouwers, B., Schrauwen-Hinderling, VB., et al.[2021]

This clinical trial will involve 210 participants with prediabetes to evaluate how different types and frequencies of exercise affect blood sugar control over 15 weeks, aiming to identify the most effective exercise regimen.

The study will not only measure changes in glycaemic control but also explore underlying mechanisms through gene expression analysis, potentially leading to improved exercise recommendations for diabetes prevention.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy of Different Modalities and Frequencies of Physical Exercise on Glucose Control in People with Prediabetes (GLYCEX Randomised Trial). Galmes-Panades, AM., Bennasar-Veny, M., Oliver, P., et al.[2022]

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]

Exercise, whether in the morning or evening, effectively delays the rise in nighttime glucose levels in individuals with obesity and impaired fasting glucose (OB+IFG), helping to manage glucose levels overnight.

However, while exercise helps control evening glucose spikes, it does not lower morning fasting glucose levels or improve the relationship between glucose and insulin concentrations in these individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Temporal optimization of exercise to lower fasting glucose levels. Kanaley, JA., Porter, JW., Winn, NC., et al.[2023]

A systematic review of 47 studies involving over 8000 individuals with prediabetes or diabetes found that while there are some risks associated with increased physical activity, such as musculoskeletal injuries and hypoglycemia, the overall prevalence of severe adverse events is low.

The review supports that increased physical activity is generally safe for individuals with prediabetes and diabetes, and it led to the development of a new risk assessment algorithm to help guide safe exercise practices for these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evidence-based risk assessment and recommendations for physical activity clearance: diabetes mellitus and related comorbidities. Riddell, MC., Burr, J.[2022]

A study involving 30 individuals with type 2 diabetes showed that structured exercise aligned with their circadian rhythm significantly improved blood sugar levels, cholesterol profiles, functionality, and quality of life over 18 weeks.

Exercising at the right time for each person's chronotype led to the greatest improvements in health markers, indicating that timing of physical activity is crucial for managing type 2 diabetes effectively.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of exercises according to the circadian rhythm in type 2 diabetes: Parallel-group, single-blind, crossover study. Menek, MY., Budak, M.[2022]

In a study of 113 elderly patients with prediabetes who completed a 2-year exercise intervention, factors such as baseline β-cell function, hemoglobin A1c levels, and body mass index were identified as significant predictors of whether participants would convert to diabetes or revert to normal glucose tolerance.

The type of exercise (aerobic vs. resistance) did not significantly impact the exercise response, suggesting that individual metabolic factors are more critical in determining the effectiveness of exercise in preventing diabetes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

β-Cell function and body mass index are predictors of exercise response in elderly patients with prediabetes. He, Y., Feng, Y., Shi, J., et al.[2022]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6908414/

Physical Activity/Exercise and Diabetes: A Position ... Acutely, aerobic exercise increases muscle glucose uptake up to fivefold through insulin-independent mechanisms. After exercise, glucose uptake remains elevated ...

2. journals.physiology.org journals.physiology.org/doi/10.1152/japplphysiol.00507.2024

Timing of resistance exercise and cardiometabolic ... When exploring within-group changes, PM exercisers reduced glucose AUC (change: −800.6 mg/dL·120 min; P = 0.01), whereas no significant change was detected for ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S2667036423000018

The importance of exercise for glycemic control in type 2 ... Habitual aerobic exercise helps manage blood glucose. Resistance exercise benefits insulin sensitivity in those with type 2 diabetes.

4. frontiersin.org frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1518871/full

Comparative effectiveness of different exercise modality on ... Various exercise interventions significantly improved glycemic and lipid profiles in prediabetic patients. HIIT and AT+RT were found to be the most effective ...

5. medicalnewstoday.com medicalnewstoday.com/articles/when-is-it-best-to-exercise-in-order-to-maintain-healthy-blood-sugar-levels

High blood sugar: Can exercising in the evenings help ... The study findings indicated that physical activity in the evening may be more beneficial for achieving stable blood sugar levels. Having ...

6. nature.com nature.com/articles/s41366-025-01721-9

Diurnal timing of physical activity in relation to obesity and ... Afternoon and evening activity provide greater metabolic health benefits than morning activity, while nighttime activity is discouraged.

7. diabetesjournals.org diabetesjournals.org/spectrum/article/36/2/146/148865/Is-There-an-Optimal-Time-of-Day-for-Exercise-A

Is There an Optimal Time of Day for Exercise? A Commentary ... On the other hand, different studies have observed improvements in overall health and glycemia from afternoon exercise compared with morning ...

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10374027/

Effects of aerobic exercises in prediabetes patients The American Diabetes Association (ADA) recommends at least 150 minutes of moderate-intensity physical activity three times a week in patients ...