Afternoon vs Morning Exercise for Prediabetes

(TIMED Trial)

Overseen By Frédérique Frisch

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Université de Sherbrooke

Must not be taking: Lipid drugs, Carbohydrate drugs

Disqualifiers: Cardiovascular disease, Liver disease, others

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

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 5

48 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine if exercising at different times of the day can help people with prediabetes manage their blood sugar and overall health more effectively. Participants will engage in high-intensity interval training (HIIT) either in the morning or afternoon to identify which timing offers greater benefits. The trial focuses on improving insulin processing and fat storage in the body. Individuals with prediabetes—characterized by elevated blood sugar levels not high enough for a diabetes diagnosis—and a BMI over 25 may be suitable candidates. As an unphased trial, this study allows participants to contribute to innovative research on the impact of exercise timing on health.

Will I have to stop taking my current medications?

Yes, you will need to stop taking certain medications. Statins must be stopped 3 weeks before the study, and metformin or anti-hypertensive drugs must be stopped 7 days before the study.

What prior data suggests that the timing of exercise is safe for individuals with prediabetes?

Research shows that high-intensity interval training (HIIT) is generally safe for most people, including those with prediabetes. Studies have found that HIIT can be done safely and leads to positive health benefits, such as better blood sugar control and improved heart health.

Participants in HIIT studies experienced lower blood sugar levels and enhanced overall fitness, with no major safety issues reported. This suggests that most people can handle HIIT well. However, since individual needs vary, consulting a doctor is important to ensure HIIT is suitable before joining a trial. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores whether the timing of exercise can impact its effectiveness in managing prediabetes. While standard care for prediabetes often includes lifestyle changes like regular exercise, this study looks at whether exercising in the morning or afternoon offers more benefits. By examining the effects of high-intensity interval training at different times of day, this trial could lead to more personalized and effective strategies for preventing the progression to diabetes.

What evidence suggests that this trial's exercise timing could be effective for prediabetes?

Research shows that high-intensity interval training (HIIT) effectively controls blood sugar and improves heart health. This trial will compare the effects of HIIT performed in the morning versus the afternoon. One study found that afternoon HIIT lowered blood sugar more effectively throughout the day than morning sessions. Another study showed that a 12-week HIIT program improved health markers in people with prediabetes and type 2 diabetes. These findings suggest that afternoon exercise might better manage blood sugar levels for those with prediabetes. Overall, HIIT is recognized for its positive effects on managing blood sugar and supporting heart health. ^{1 6 7 8 9}

Who Is on the Research Team?

Denis P. Blondin, PhD

Principal Investigator

Université de Sherbrooke

Are You a Good Fit for This Trial?

This trial is for men and women with prediabetes, defined by specific blood sugar levels or insulin resistance. Participants must have a BMI over 25, be able to follow the study protocol, and provide informed consent. Exclusions include recent scans, smoking, heavy drinking, certain medical conditions like uncontrolled thyroid disorders or heart disease, and use of medications affecting metabolism.

Inclusion Criteria

To be willing and able to adhere to the specifications of the protocol

To have signed an informed consent document indicating that they understood the purpose of and procedures required for the study and were willing to participate in the study.

I have pre-diabetes or insulin resistance based on my blood sugar tests.

Exclusion Criteria

My cholesterol or triglycerides levels have been high.

You have a pacemaker.

I have heart disease confirmed by my doctor and tests.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline Metabolic Study

Participants complete Visit A (baseline) followed by a glycogen lowering exercise bout

1-2 weeks

2 visits (in-person)

Acute Exercise and Metabolic Study

Participants undergo an acute exercise bout and return for Visit B 18-24 hours later

1 week

2 visits (in-person)

12-week Exercise Training

Participants engage in a 12-week supervised high-intensity interval training program

12 weeks

Regular visits every other day

Final Metabolic Study

Participants return for Visit C at least 48 hours after the last exercise bout

1 week

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the intervention

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• High-intensity interval training

Trial Overview The trial tests whether exercising at different times (morning vs late afternoon) affects blood sugar control in people with prediabetes. It aims to see if timing exercise can improve how the body uses insulin and manages dietary fats in muscles and fat tissue.

How Is the Trial Designed?

Group I: Afternoon exercise Experimental Treatment 1 Intervention

Participant to perform high-intensity interval training in the morning (\~4 pm)

Group II: Morning exercise Active Control 1 Intervention

Participant to perform high-intensity interval training in the morning (\~9 am)

Who Is Running the Clinical Trial?

Université de Sherbrooke

Lead Sponsor

Trials

317

Recruited

79,300+

Laval University

Collaborator

Trials

439

Recruited

178,000+

Wageningen University

Collaborator

Trials

177

Recruited

44,600+

McMaster University

Collaborator

Trials

936

Recruited

2,630,000+

Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

Collaborator

Trials

722

Recruited

2,726,000+

Maastricht University Medical Center

Collaborator

Trials

992

Recruited

3,304,000+

University of Calgary

Collaborator

Trials

827

Recruited

902,000+

University of Waterloo

Collaborator

Trials

132

Recruited

221,000+

Leiden University Medical Center

Collaborator

Trials

580

Recruited

623,000+

Published Research Related to This Trial

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]

High-intensity (HI) exercise training is a time-efficient alternative to traditional moderate-intensity (MI) exercise for prediabetic adults, allowing them to meet physical activity guidelines with less overall time commitment.

HI exercise training has been shown to improve skeletal muscle metabolic control and cardiovascular function comparably or even superiorly to low-intensity (LI) and MI exercise, making it an effective option for reducing cardiometabolic risk in prediabetic patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-intensity exercise training for the prevention of type 2 diabetes mellitus. Rynders, CA., Weltman, A.[2014]

Individuals with prediabetes showed better adherence to high-intensity interval training (HIIT) compared to traditional moderate-intensity continuous training (MICT), with adherence rates of 89% for HIIT versus 71% for MICT after one month.

Participants in the HIIT group engaged in significantly more vigorous physical activity per week (24 minutes) compared to those in the MICT group (11 minutes), while both groups experienced similar improvements in cardiorespiratory fitness and blood pressure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-intensity interval training as an efficacious alternative to moderate-intensity continuous training for adults with prediabetes. Jung, ME., Bourne, JE., Beauchamp, MR., et al.[2022]

A 12-week elliptical high-intensity interval training (HIIT) program significantly improved metabolic risk factors in 16 participants with pre- and type 2 diabetes, including reductions in fasting blood glucose and waist circumference.

Participants also experienced enhancements in body composition, such as increased lean body mass and improved cardiovascular fitness (VO2max), indicating that HIIT can be an effective intervention for managing diabetes-related health issues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Elliptical High Intensity Interval Training on Metabolic Risk Factor in Pre- and Type 2 Diabetes Patients: A Pilot Study. Fex, A., Leduc-Gaudet, JP., Filion, ME., et al.[2022]

A 12-week study involving 32 prediabetic male patients showed that high-intensity interval training (HIIT) significantly reduced blood glucose levels compared to continuous endurance training at anaerobic threshold (CETAT).

Both HIIT and continuous endurance training at maximal fat oxidation (CETFAT) improved insulin resistance indices similarly, indicating that exercise intensity and type can effectively influence hormonal changes in prediabetic individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-Intensity Interval vs. Continuous Endurance Training: Preventive Effects on Hormonal Changes and Physiological Adaptations in Prediabetes Patients. Safarimosavi, S., Mohebbi, H., Rohani, H.[2022]

A 16-week supervised high-intensity aerobic exercise program significantly improved health markers in individuals with metabolic syndrome, including body composition, blood pressure, and cardiorespiratory fitness, with no differences between morning and afternoon exercise groups.

However, morning exercise (AMEX) was more effective than afternoon exercise (PMEX) in reducing systolic blood pressure and insulin resistance, suggesting that the timing of exercise can influence cardiometabolic health benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy of morning versus afternoon aerobic exercise training on reducing metabolic syndrome components: A randomized controlled trial. Morales-Palomo, F., Moreno-Cabañas, A., Alvarez-Jimenez, L., et al.[2023]

High-intensity interval training (HIIT) significantly improves functional capacity, as measured by VO2max, by 3.02 mL/kg/min compared to moderate-intensity continuous training (MICT) in individuals with prediabetes and type 2 diabetes (T2D).

Both HIIT and MICT show similar effects on cardiometabolic markers such as HbA1c and cholesterol levels, indicating that while HIIT may enhance physical fitness, it does not provide additional benefits for metabolic health compared to MICT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-intensity interval training versus continuous training on physiological and metabolic variables in prediabetes and type 2 diabetes: A meta-analysis. De Nardi, AT., Tolves, T., Lenzi, TL., et al.[2018]

High-intensity interval training (HIIT) is effective in improving glycemic control in overweight adults with prediabetes, as shown in a study involving 60 participants over 12 weeks.

Among the HIIT methods tested, high-volume HIIT (HV-HIIT) was more effective than low-volume HIIT (LV-HIIT) in significantly reducing A1C and fasting blood glucose levels, suggesting it may better prevent progression to type 2 diabetes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Different Dosages of Interval Training on Glycemic Control in People With Prediabetes: A Randomized Controlled Trial. RezkAllah, SS., Takla, MK.[2020]

A 6-week high-intensity interval training (HIT) program, requiring less than 15 minutes per session, significantly improved key health markers in 189 sedentary adults with pre-existing risk factors for type 2 diabetes, including a 10% increase in fitness levels and a 16% reduction in insulin resistance.

The HIT protocol also effectively lowered mean arterial blood pressure by 3%, demonstrating that this time-efficient exercise regimen can be as effective as longer, traditional exercise programs in managing cardio-metabolic risk factors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Practical and Time-Efficient High-Intensity Interval Training Program Modifies Cardio-Metabolic Risk Factors in Adults with Risk Factors for Type II Diabetes. Phillips, BE., Kelly, BM., Lilja, M., et al.[2019]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4334091/

Effectiveness and Safety of High-Intensity Interval Training ... IN BRIEF Recent research has shown that high-intensity interval training (HIIT) can promote improvements in glucose control and cardiovascular health in ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6323076/

Afternoon exercise is more efficacious than morning ... Conversely, afternoon HIIT lowered blood glucose at several time points throughout the day compared with pre-training and morning HIIT. Our ...

3. withpower.com withpower.com/trial/phase-prediabetic-state-8-2021-4523e

Afternoon vs Morning Exercise for Prediabetes (TIMED Trial) A 12-week elliptical high-intensity interval training (HIIT) program significantly improved metabolic risk factors in 16 participants with pre- and type 2 ...

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

The importance of exercise for glycemic control in type 2 ... Recent work also shows high-intensity interval training is successful at lowering blood glucose, as is breaking up sedentary behavior with short-bouts of light ...

5. nature.com nature.com/articles/s41598-024-67331-z

Comparative effects of high-intensity interval training and ... The purpose of this study was to compare the effects of High-Intensity Interval Training (HIIT) and Moderate-Intensity Continuous Training (MICT) on weight, ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6528388/

Effects of Different Dosages of Interval Training on ... LV-HIIT and HV-HIIT significantly reduced A1C and FBG; however, HV-HIIT yielded a greater reduction in A1C than LV-HIIT (26.07 vs. 14.50%) and in FBG (17.80 vs.

7. dom-pubs.onlinelibrary.wiley.com dom-pubs.onlinelibrary.wiley.com/doi/full/10.1111/dom.16220

Efficacy of high‐intensity interval training in individuals with ... The data indicated that HIIT significantly improves glycosylated haemoglobin and cardiorespiratory fitness compared with CON (weighted mean ...

8. sciencedirect.com sciencedirect.com/science/article/pii/S1728869X23000448

Effects of low-versus high-volume high-intensity interval ... Another study in prediabetes has compared the two HIIT subtypes in combination with a low-calorie diet and found that high-volume HIIT was more effective than ...

9. ama-assn.org ama-assn.org/public-health/prevention-wellness/why-your-patients-prediabetes-might-benefit-interval-training

Why your patients with prediabetes might benefit from ... Findings from this study suggest that training-induced increases in oxidative capacity may contribute to cardiometabolic risk reduction, showing ...