In case you haven’t heard: Exercise is really good for people with type 2 diabetes. It helps control blood sugar levels, increases energy levels, improves heart health, and promotes emotional well-being. Barring other medical complications, the majority of people with diabetes can and should exercise for diabetes control and for better overall health and well-being.
How does exercise lower blood sugar?
Exercise lowers blood sugar in two ways:
- First, exercise increases insulin sensitivity. This means that your cells are better able to use available insulin to absorb sugar from the bloodstream to be used as energy for your body.
- Second, exercise stimulates another mechanism that allows your muscles to absorb and use sugar for energy, even without insulin.
Not only does exercise lower blood sugar levels in the short term, but exercising over time also contributes to lower A1C levels over time.
How important is exercise?
Leading a sedentary (or inactive) lifestyle is one of the major risk factors for developing type 2 diabetes, and the high incidence of obesity and overweight among people with type 2 is also highly correlated with inactivity. Starting a workout program can lower body mass and consequently decrease the insulin resistance of type 2 diabetes; studies have shown that people with type 2 diabetes who exercise regularly have better A1c profiles than those who don’t. Along with medical nutrition therapy, exercise is one of the first lines of defense in type 2 diabetes control.
In addition, exercise is a key tool in preventing one of the leading complications of type 2 diabetes—cardiovascular disease. Studies have shown that regular activity lowers triglyceride levels and blood pressure.
How much exercise do you need?
The American Diabetes Association (ADA) recommends the following physical activity for adults with type 2 diabetes for blood sugar benefits and overall health:
- At least two and a half hours of moderate to vigorous intensity physical activity per week (i.e., brisk walking, water aerobics, swimming, or jogging).
- Two to three sessions of resistance exercise per week. Resistance exercise is physical activity that strengthens muscle strength, such as lifting five pound weights or doing pushups.
- No more than two days in a row without physical activity.
- Breaking up sitting time every 30 minutes during the day.
- Incorporate flexibility exercises, like stretching or yoga into your weekly routine.
Make an appointment to see your doctor before starting an exercise program. If you have certain diabetic complications, like nerve damage, eye disease, and kidney disease, your doctor may recommend very specific ways to exercise.
Because exercise typically has a blood glucose lowering effect, if you are taking insulin or certain medications called sulfonylureas and glinides, you need to pay particular attention to their blood glucose levels before, during, and after exercise. Talk to your doctor about taking certain measures to prevent blood sugar emergencies. If you are not taking these medications, you do not need to worry about your blood sugar going too low due to exercise, but you can still test your blood sugar to learn how exercise impacts your body over time.
Once you’ve gotten approval to start a fitness program, follow these tips to stay safe while you exercise:
- Keep a log. Use an exercise log to track your exercise activities and your blood sugar levels before and after exercise.
- Stay hydrated. Drinking water before, during, and after exercise is important for reducing your risk of dehydration associated with erratic blood sugars and heat stroke.
- Warm up and cool down. The ADA recommends a warmup of 5 to 10 minutes of aerobic activity (walking, cycling, etc.) at a low-intensity level and gentle stretching for an additional 5 to 10 minutes. The cool-down should also last 5 to10 minutes until heart rate has returned to pre-exercise levels.
- Dress appropriately. Wear well-fitting shoes and socks and breathable and weather-appropriate clothing to prevent foot problems and heat stroke. Consider a visit to your podiatrist before starting an exercise program.
- Breathe normally. When strength training, do not hold your breath, as it can affect your blood pressure and cause you to feel lightheaded. See your doctor for medical clearance before starting resistance or strength training.
- Start slow. If you’re new to exercise, or if you’ve been inactive for a long time, start off by going easy on yourself, increasing tempo, distance, and time as you gradually build your stamina over time.
- Save your breath. A slight shortness of breath is normal during cardio training, but laboring to catch your breath is not. You should be able to carry on a conversation while you exercise.
- Carry a phone. If exercising outdoors, always have access to emergency medical service via a cell phone or other means of communication.
Updated by Julia Telfer, M.P.H., 3/17.