Breaking up Sedentary Time to Improve Glucose Control in a Population at Risk for Developing Type 2 Diabetes

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.