Removal of Exercise for Impaired Glucose Tolerance

Overseen By Leryn Reynolds

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: Old Dominion University

Must not be taking: Blood glucose medications

Disqualifiers: HIV, Hepatitis, Tuberculosis, Smoking, others

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

Compensation: Varies

Number of Visits: Unknown

40 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how stopping exercise affects blood sugar control and blood vessel health in active older adults. Researchers aim to determine how quickly these health aspects change when exercise is paused and how fast they recover when exercise resumes. Participants will either stop exercising for a few days and then restart, or continue their regular exercise routine. Ideal candidates are healthy, physically active individuals who exercise at least 90 minutes per week and have no physical limitations affecting their activity levels. As an unphased trial, this study allows participants to contribute to understanding the health impacts of exercise habits.

Will I have to stop taking my current medications?

Yes, you will need to stop taking medications that alter blood glucose levels to participate in this trial.

What prior data suggests that the removal of exercise is safe for older adults?

Research has shown that increased physical activity can reduce the risk of diabetes in individuals with high blood sugar levels. However, limited information exists on the effects when active individuals temporarily stop exercising. The study under consideration will examine the impact of short breaks from exercise in active older adults.

As this trial is in its early stages, specific safety information is not yet available, but the risks are likely low. Researchers will closely monitor participants to track any changes in blood sugar or blood vessel health.

Active older adults considering participation may find this trial a safe way to learn how short breaks from exercise might affect their health. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores the effects of removing exercise entirely, even for short periods, on glucose tolerance and vascular health. Unlike current treatments for impaired glucose tolerance, which often rely on medications or recommend consistent physical activity, this trial examines what happens when exercise is temporarily stopped. This approach could reveal critical insights into how the timing and frequency of exercise impact blood sugar control and vascular function, potentially leading to new guidelines for managing glucose levels without continuous exercise.

What evidence suggests that the removal of exercise could impact glycemic control and endothelial function in older adults?

Research has shown that regular exercise is crucial for managing blood sugar levels and reducing the risk of type 2 diabetes. Studies indicate that physical activity helps control blood sugar after meals and maintains healthy blood vessels. Ceasing exercise, even briefly, can diminish these benefits, resulting in higher blood sugar and less healthy blood vessels. In this trial, researchers will divide participants into two groups: one group will have their blood vessel health measured during periods of exercise and inactivity, while the other group will have their blood glucose levels monitored under similar conditions. The study aims to determine how quickly these changes occur in older adults who are usually active and whether returning to exercise can swiftly restore these benefits. ^{1 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for healthy, physically active older adults aged 55 and above who currently exercise at least 90 minutes per week. It's also open to those between 18-40 years old. Participants should not have physical limitations that could affect changes in their daily activity levels.

Inclusion Criteria

Healthy, physically active, performing at least 90 min/week of physical activity

I don't have physical limitations affecting my daily activities.

Exclusion Criteria

Body weight change of greater than 5% within the previous 2 months

Smoking within the previous 2 months

I have been diagnosed with HIV, hepatitis, or tuberculosis by a doctor.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Exercise Phase (EX)

Participants perform their normal exercise routines while having their blood vessel health and blood glucose levels measured.

3 days

Continuous monitoring

No Exercise Phase (NOEX)

Participants undergo 1, 3, or 5 days of no exercise to assess impairments in glycemic control and endothelial function.

1-5 days

Continuous monitoring

Return to Exercise Phase (REX)

Participants return to exercise for 1 to 3 days to assess restoration of glycemic control and endothelial function.

1-3 days

Continuous monitoring

Follow-up

Participants are monitored for safety and effectiveness after the intervention phases.

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Removal of Exercise

Trial Overview The study aims to see if stopping exercise briefly affects blood sugar control and blood vessel health in older adults who usually stay active. Researchers will check how fast these effects happen with no exercise, and if going back to exercising for three days can reverse any negative impacts.

How Is the Trial Designed?

Group I: Vascular Experimental Treatment 1 Intervention

Vascular: Participants will have their blood vessel health measured while performing their normal exercise routines (EX) and while undergoing 1, 3, 5 days of no exercise (NOEX) followed immediately by 1 and 3 days of return to exercise (REX).

Group II: Metabolic Experimental Treatment 1 Intervention

Metabolic: Participants will have their blood glucose levels measured via continuous glucose monitoring for 3 days while participating in their normal exercise routines (EX). Participants will also have their blood glucose levels measured for 3 days while not exercising (NOEX), following immediately by 3 days of a return to normal activity(REX). Participants will be randomized to participate in the EX or NOEX/REX phases first. The EX and NOEX/REX phases will be separated by at least 1 week

Who Is Running the Clinical Trial?

Old Dominion University

Lead Sponsor

Trials

25

Recruited

15,500+

Published Research Related to This Trial

A systematic review of 5 randomized controlled trials involving 549 participants found that structured exercise interventions can lead to significant improvements in physical activity levels and body composition shortly after the intervention, but these benefits may not be sustained long-term.

Only one of the studies showed lasting improvements in physical activity levels up to 5 years post-intervention, highlighting the need for further research on how to maintain increased physical activity after structured exercise programs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Long-Term Physical Activity Levels After the End of a Structured Exercise Intervention in Adults With Type 2 Diabetes and Prediabetes: A Systematic Review. Booth, JE., Benham, JL., Schinbein, LE., et al.[2021]

Regular vigorous exercise can prevent the decline in glucose tolerance and insulin sensitivity associated with aging, and may completely normalize glucose tolerance in some patients with mild non-insulin dependent diabetes mellitus (NIDDM) and impaired glucose tolerance (IGT).

To achieve normalization of glucose tolerance, patients need to engage in approximately 25 to 35 kilometers of running or an equivalent amount of other vigorous exercise each week, particularly if they still have the ability to secrete insulin and insulin resistance is the main issue.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of exercise on glucose tolerance and insulin resistance. Brief review and some preliminary results. Holloszy, JO., Schultz, J., Kusnierkiewicz, J., et al.[2019]

In a study of 92 patients with type 2 diabetes, higher volumes of exercise were linked to increased odds of discontinuing glucose-lowering medications, with the highest exercise group showing an odds ratio of 34.4 compared to standard care.

Significant improvements in cardiovascular risk factors, such as glycated hemoglobin and triglyceride levels, were observed in patients who exercised more, particularly in the intermediate and upper exercise tertiles, indicating that exercise can enhance overall health in diabetes management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dose-Response Effects of Exercise on Glucose-Lowering Medications for Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial. MacDonald, CS., Johansen, MY., Nielsen, SM., et al.[2022]

Physical inactivity is a significant risk factor for impaired glucose tolerance (IGT), insulin resistance, and type 2 diabetes, highlighting the importance of regular physical activity in preventing these conditions.

Regular exercise training improves insulin action and glucose tolerance in individuals at risk for type 2 diabetes, making it an effective therapeutic intervention to combat insulin resistance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exercise as a therapeutic intervention for the prevention and treatment of insulin resistance. Hawley, JA.[2006]

Physical activity is crucial for preventing and managing type 2 diabetes and cardiovascular risks, but individuals with diabetes face higher risks of injury during exercise due to complications associated with the disease.

To ensure safe exercise for people with type 2 diabetes, it is important to tailor exercise programs to individual health conditions and complications, such as diabetic foot and retinopathy, while implementing preventative measures to minimize risks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prevention of exercise-related injuries and adverse events in patients with type 2 diabetes. Mendes, R., Sousa, N., Reis, VM., et al.[2013]

Impaired glucose tolerance (IGT) significantly increases the risk of developing non-insulin-dependent diabetes mellitus (NIDDM), highlighting the importance of early intervention.

Engaging in moderately vigorous aerobic exercise, such as walking or cycling for at least 30 minutes three times a week, is recommended as an effective strategy for preventing NIDDM in individuals with IGT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Management of impaired glucose tolerance: physical training therapy]. Sato, Y., Sato, J., Tokudome, S.[2011]

Exercise can greatly benefit people with diabetes, but it's crucial to measure glucose levels before starting to ensure safety during workouts.

Guidelines have been developed to help exercise specialists determine when to start or stop exercise based on glucose levels, with specific contraindications such as low glucose (<4.0 mmol/L) or high glucose (>15.0 mmol/L with symptoms).

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Resources to Guide Exercise Specialists Managing Adults with Diabetes. Turner, G., Quigg, S., Davoren, P., et al.[2020]

Citations

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Removal of Exercise for Impaired Glucose Tolerance Trial Overview The study aims to see if stopping exercise briefly affects blood sugar control and blood vessel health in older adults who usually stay active.

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Relative effectiveness of different exercise interventions on ... The American Diabetes Association (ADA) has also clearly indicated that exercise intervention can significantly alleviate T2DM-related symptoms ...

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Cognitive Effects of Aerobic Exercise for IGT Adults Exercise has salutary effects on glucoregulation and visceral adiposity, an important link for adults with impaired glucose tolerance (IGT) and type 2 diabetes ...

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Both resistance- and endurance-type exercise reduce ... In conclusion, a single session of resistance- or endurance-type exercise substantially reduces the prevalence of hyperglycaemia and improves glycaemic control ...

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Association of Habitual Daily Physical Activity With Glucose ... In addition, large clinical trials have shown that increased physical activity can lower diabetes risk in individuals with impaired glucose tolerance (8–10). ...

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EXIT: Prospective Study of the Response to Exercise ... The main outcome measures will be the change in hepatic triglyceride content and glucose area under the curve during a 75g, 2-hour oral glucose tolerance test.

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High-Intensity Interval Training for Individuals With Isolated ... This study is a 1:1 proof-of-concept randomized controlled trial involving 34 physically inactive individuals (aged 35-65 years) who are overweight or obese ...

9. liebertpub.com liebertpub.com/doi/full/10.1089/dia.2025.8809.dpz

Advances in Exercise and Nutrition as Therapy in Diabetes The diet-plus-exercise intervention was significantly associated with a decreased risk of all-cause death [HR 0.64, 95% CI (0.48–0.84)], CVD ...