Heart Rate Variability-Guided Exercise Training in Type 2 Diabetes

This study will examine participant's fitness levels before and after a 16 week intervention period. There are two study visits prior to starting the intervention period. During Baseline Study Visit #1, the investigators will take a health history, determine the height and weight of the participants, and have participants complete a physical activity questionnaire and a 3-day diet log, as well as determine muscle and fat mass, followed by tests that examine how blood vessels function, and lastly a treadmill test to determine aerobic fitness. During Baseline Study Visit #2, which takes place 5-7 days later, the investigators will measure blood pressure, heart rate, and glucose control through a glucose challenge test. The glucose challenge tests requires taking \~3 Tablespoons of blood to be assessed for glucose, insulin and hemoglobin A1c. Lastly, participants will complete 3 questionnaires regarding quality of life, fatigue, and depression. After completion of the two pre-training data collection visits, participants will be randomized to 1 of 3 groups: 1) HRV-guided exercise group (HRV); 2) traditional exercise training group (TRAD); or 3) usual care group. There will be approximately 30 subjects in each group, providing an equal chance of being assigned to either group. Both the HRV and TRAD groups will participate in a combined lab-supervised and home-based exercise program (with 1 day1 per week supervised in the laboratory and 3 days per week at home) over the course of 16 weeks. Furthermore, both exercise groups will participate in online/phone counseling in order to provide support. Specifically, participants will be provided with a phone number to the lab to call study personnel for assistance if needed. Weekly internet video chats through Zoom or phone calls, if Zoom is unavailable, will be conducted by a trained exercise-behavior change coach to help participants focus on self-efficacy, outcome expectations, impediments (barriers), and goal setting. Post-training testing Visits #3 and #4 Visits #3 and #4 will be identical to visits #1 and 2, with the exception that the demographic questionnaire will not be administered again. This will mean there is a total of 100 mL of blood taken over the course of the entire study, between Visits 2 and 4 combined, which will total \~6 total Tablespoons.