Primary Outcome Measures:
- Hemoglobin A1C [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- Fasting glucose [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- Basal insulin [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- Resting blood pressure [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- C reactive protein [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- Visceral adiposity [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- Body Composition [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- Cardiorespiratory fitness [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- Muscular strength [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
- metabolic measures, including serum cholesterol and triglycerides [ Time Frame: at 9 months ] [ Designated as safety issue: No ]
Although it is generally accepted that regular exercise provides substantial health benefits to individuals with T2D, the exact exercise prescription in terms of type (AT versus RT versus AT+RT) still remains largely unexplored, particularly in regard to week-to-week glucose control as assessed by HbA1C.
There is a need for more adequately powered and well-controlled studies to examine the effects of RT, AT and AT+RT on HbA1C in individuals with T2D. With the incidence of T2D expected to increase dramatically in the coming years, it is essential to have a better understanding of the relative benefits of various exercise interventions. This information can help better formulate exercise recommendations for patients with T2D as well as potentially provide more exercise options, which is important given the small percentage of individuals with TD2 who regularly exercise.The study group will be sedentary women and men with T2D, aged 30 to 75 years. We will randomly assign 360 individuals to an aerobic exercise training only group (AT; n=100), a resistance training only group (RT; n=100), a combination of aerobic plus resistance training (AT+RT; n=100), or a standard care group (SC; n=60). The AT individuals will participate in 3 or 4 training sessions each week for 9 months progressing to a total energy expenditure of 12 kcal/kg/week (KKW), which is an exercise dose consistent with the current public health recommendations for physical activity for individuals with T2D. 1, 2 The target exercise intensity will be 50%-80% of baseline VO2 max. The RT group will participate in 3 sessions per week (9 exercises, 2-3 sets each), which focuses on large muscle groups. This RT regimen is based on the studies that most successfully improved HbA1C in individuals with T2D. Individuals in the AT+RT group will complete 10 KKW of aerobic training and a reduced resistance-training regimen of 2 sessions per week (9 exercises, 1 set of each). The AT+RT regimen represents the exercise recommendations of the American College of Sports Medicine (ACSM) and the American Diabetes Association (ADA).3, 4 All participants, including those in the SC group will complete a one hour consultation with a Certified Diabetes Educator (CDE) following randomization, during which, participants will be provided with educational materials and general guidelines for healthy living. Participants will also complete monthly sessions with the CDE, during which they will receive further instruction and guidance.
Simply stated, we wish to compare the effect of resistance training alone, resistance in combination with aerobic training, and aerobic training alone to standard care on HbA1C, in initially sedentary women and men with T2D. The primary outcome measure is HbA1C, an integrated measure of blood glucose control over the past 8-12 weeks. Other outcomes of interest include homeostasis model assessment (HOMA), resting blood pressure, C-reactive protein (CRP), visceral adiposity, total body fat, and lean muscle mass as measured by DEXA, cardiorespiratory fitness, muscular strength, and metabolic measures including serum cholesterol and triglycerides.