Exercise is one of the most important things you can do to stay healthy if you have diabetes. Yet most people with the disease and those at high risk of the disease aren’t getting enough—even though research shows that a combination of regular exercise and modest weight loss can help prevent or control the disease.
As a result, the American Diabetes Association (ADA), in partnership with the American College of Sports Medicine, has issued exercise guidelines specifically for individuals with diabetes.
The guidelines call for an exercise program that includes both aerobic exercise and strength training.
Also called cardiovascular exercise, aerobic exercise gets your heart pumping and your muscles moving. Common examples of aerobic exercise include walking, running, swimming, and biking. Even playing with children—if done at an intensity level similar to brisk walking—can be considered aerobic exercise.
During aerobic exercise, your muscles require energy to contract. They obtain this energy from the glucose in your blood, which helps keep glucose levels under control.
Also, a single aerobic workout can improve insulin action for more than 24 hours, and more long-lasting benefits may be observed with sustained activity. The ADA guidelines call for at least 2.5 hours of moderate-to-vigorous aerobic exercise per week spread out over at least three days—with no more than two consecutive days between workouts.
The guidelines recommend working out at 40 to 60 percent of your maximum exertion level, which can be formally determined by an exercise stress test.
For many people with type 2 diabetes, brisk walking may be enough to improve blood glucose control. For those at risk of developing type 2 diabetes, a good workout can lower their risk.
A meta-analysis of 10 studies found that people who followed the guidelines and walked briskly for 2.5 hours per week were 70 percent less likely to develop diabetes. However, research shows that the intensity of physical activity is an important predictor of blood glucose control, so the more vigorous your workouts, the better.
Also known as resistance exercise, strength training does just what it says—it strengthens your muscles. Strength training involves the use of free weights or weight machines to build muscle.
The guidelines recommend that each strength training session include five to 10 exercises that target the major muscle groups, such as the upper body, the lower body, and the core.
How do you know the correct weight to use? You’re using the correct weight if you can perform 10 to 15 repetitions of the exercise before becoming fatigued.
If you’re a beginner, start out with one set of repetitions for each exercise and gradually work up to three or four sets. As you progress and the exercises become easier, gradually increase the weights to ones you can lift eight to 10 times.
Since it’s important to use proper form when doing strength training, seek out a qualified exercise trainer for instruction and periodic evaluations.
The benefits of strength training for those with type 2 diabetes have been well documented. For example, a 16-week program of twice-weekly strength training in older men who had just been diagnosed with type 2 diabetes was associated with a 46 percent increase in insulin action, a 7 percent reduction in fasting blood glucose levels, and a significant loss of visceral fat.
Strength training may also improve blood glucose levels by increasing muscle mass. Muscles feed on glucose, and the more muscle mass you have, the more glucose it will take from your bloodstream.
Some forms of exercise, like walking, are so safe that they rarely require pre-exercise approval. However, it’s a good idea to let your doctor know about any exercise program you plan to begin so that he or she can discuss how it may impact your blood glucose levels and medication or insulin use.
While exercise can improve diabetes-related complications in the long run, it can present challenges in the short term. If you have any diabetes-related complications, it is especially important to consult with your doctor before beginning an exercise program.
Read more about how to better control your blood sugar levels.
Timothy Gower is an award-winning journalist who writes about health and medicine. His work has appeared in more than two dozen major magazines and newspapers, including Prevention, Reader’s Digest, and the Los Angeles Times.