Physical activity has many health benefits in people with type 1 and type 2 diabetes. Clinicians must be comfortable counseling patients with both types of diabetes on how to participate safely in various types of physical activity. According to the American Diabetes Association (ADA), most people with diabetes do not need further testing before initiation of low- to moderate-intensity exercise. Recommended physical activity for adults includes at least 150 min/week of moderate-intensity aerobic activity plus resistance training 2 to 3 times/week; for children and adolescents the recommendation is 60 min/day. Important steps to ensure safe participation in physical activity include modifying the insulin regimen and carbohydrate intake, as well as more frequent monitoring of blood glucose in the time periods surrounding exercise. For patients using multiple daily insulin injections, the preprandial bolus insulin dose typically should be decreased relative to the expected intensity and duration of aerobic exercise. For those using continuous subcutaneous insulin infusion pumps, the basal insulin rate should be reduced by 50% to 80% approximately 90 min before aerobic exercise. Continuous glucose monitoring provides an opportunity for more frequent glucose monitoring and tighter glycemic control during exercise participation.

Case 4. MT is a 63-year-old woman who comes to your office for follow-up of type 2 diabetes, which was diagnosed at age 52 years. She takes metformin, uses a once daily dose of a basal insulin, and uses short-acting preprandial insulin boluses. Blood glucose has been stable, and the point-of-care A1c today is 7.8 mg/dL. She recently retired and anticipates having more time to exercise. She wants to set a goal for physical activity and is interested in joining a local group that walks together a few times per week. She can perform her activities of daily living without shortness of breath or chest pain. She has had no prior cardiac testing. She asks if she needs any additional evaluation before starting a walking program.