NCT05041491 · University of Colorado, Denver
Breaking up Sedentary Time to Improve Glucose Control in a Population at Risk for Developing Type 2 Diabetes
(BURST2D)
What this study is about
Newly released guidelines recommend increased physical activity (PA) and reduced sedentary behaviors (SB) to improve glycemia and prevent the onset and progression of type 2 diabetes (T2D). Typically, 30-60 min bouts of PA are advocated per day. Although this approach increases PA, it does not decrease the length of the sedentary periods through the day.
View original scientific description
Newly released guidelines recommend increased physical activity (PA) and reduced sedentary behaviors (SB) to improve glycemia and prevent the onset and progression of type 2 diabetes (T2D). Typically, 30-60 min bouts of PA are advocated per day. Although this approach increases PA, it does not decrease the length of the sedentary periods through the day. This is important because recent epidemiological data suggest that frequently interrupting sedentary time improves glucose control even in people who achieve the recommended levels of PA. Preliminary experimental data suggest that breaking up prolonged sedentary time by performing multiple short bouts (5 min) of PA throughout the day, may improve glycemia more than performing a single continuous bout of PA, and thereby potentially be a novel strategy to prevent T2D. The improvement in glycemia was observed even when the total amount of PA and total energy expenditure were matched, suggesting that how and when PA is performed over the day may matter more than how much PA is done. However, important gaps in knowledge remain including: (1) whether similar benefits on glucose control would be observed in adults with prediabetes, a clinically relevant population that is at high risk of developing T2D; (2) whether these effects are sustained or diluted over time, and (3) what are the mechanistic underpinnings. To address these gaps, the investigators propose to measure the acute and chronic effects of PA breaks on glucose control and the underlying mechanisms in individuals at risk of developing T2D. Sedentary men and women with prediabetes (n=66, 50% F) will be randomized to either an intervention designed to interrupt SB with 5-min bouts of brisk walking performed hourly for 9 hours/day, 5 days/week (BREAK) or a control condition consisting of 45-min of brisk walking performed as a single daily continuous bout, 5 days/week (ONE). The two 3-months interventions will be matched for total active time.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Male and female
- BMI of 18.5-40 kg/m2 and weight stable over the previous 6 months.
- Age, 18-64 years old.
- Fasting glucose of 100-125 mg/dL or fasting HbA1c of 5.7-6.4%, or 2h OGTT blood glucose of 140-199mg/dL based on the American Diabetes Association criteria for pre-diabetes. Fasting glucose, HbA1c and OGTT results ordered by the participant's provider within 3-months of the screening visit will be accepted, provided they fall within the measurement of error range established by the institution's lab standards. Additionally, consistent use of Metformin (1 year) to prevent prediabetes from developing diabetes will be accepted.
- Less than 150 minutes of moderate-to-vigorous physical activity (MVPA) per week and more than 6 hours of sitting time per day, as self-reported by the volunteers using the International Physical Activity Questionnaire (IPAQ).
- Less than 6500 of steps per day as measured by a pedometer over 5 days (at least 1 weekend day).
- Passing medical and physical screening, and analysis of blood and urine screening samples.
- Low-moderate caffeine use (\<3 cups/day).
- Agree to refrain from any other structured exercise than the physical activity prescribed in each arm of the study.
- Agree to eat control diets for 3 days before and during the Clinical and Translational Research Center (CTRC) visits;
- Agree to refrain from taking any over-the-counter (including nonsteroidal anti-inflammatory drugs) or prescribed medication (apart from oral contraceptives) for 3 days prior to the inpatient CTRC visits;
- Agree to wear a Fitbit® activity monitor and upload data on the website on a daily basis for the whole duration of the study.
- Agree to follow the physical activity interventions and to be randomly assigned to one of the two arms of the study.
- Agree to complete all the study procedures.
Exclusion criteria
- Pregnancy, breast-feeding or post-menopause for women.
- Being considered unsafe to participate as determined by the study physician.
- Ever having a history of systemic, psychiatric, neurological disease, or drug and alcohol abuse.
- History of cardiovascular disease, diabetes, uncontrolled hypertension, untreated thyroid, renal, hepatic diseases, dyslipidemia or any other medical condition affecting weight or lipid metabolism.
- Being positive for human immunodeficiency virus or hepatitis B or C.
- Taking medications affecting weight, triglycerides, energy intake/energy expenditure, or sleep in the last 3 months.
- Having abnormal blood chemistry and/or hematology as deemed significant by the study physician.
- Being a smoker or having been a smoker in the 3 months prior to their screening visit.
- Having donated over 400 mL of blood within 3 months (90 days) of screening for the study;
- Working night shifts within 1 month of and throughout the study.
- Not completing the trial days of BREAK and ONE during the screening period to assess the willingness and ability of the participant to perform each of the interventions.
Where
- Aurora, Colorado
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 29, 2025 · Source of record for eligibility and locations