This Physician’s Weekly feature on physical activity recommendations for patients with diabetes was completed in cooperation with the experts at the American Diabetes Association.
The CDC estimates that 25.8 million Americans have diabetes and another 79 million have prediabetes, a condition characterized by A1C, fasting glucose, or oral glucose tolerance levels that are higher than normal but not high enough to be classified as diabetes. Research has shown that regular physical activity (PA) may prevent or delay diabetes and its complications, but most people with type 2 diabetes are not physically active. “PA is central to the management and prevention of type 2 diabetes and prediabetes,” says Sheri R. Colberg, PhD, FACSM. “It helps treat associated glucose, lipid, and blood pressure control abnormalities, and aids in weight loss and weight maintenance.” She adds that medications used to control type 2 diabetes should augment lifestyle improvements rather than replace them.
Help for Healthcare Providers
In the December 2010 issues of Diabetes Care and Medicine & Science in Sports & Exercise, the American Diabetes Association and the American College of Sports Medicine issued guidelines on exercise for people with type 2 diabetes as a joint position statement. The recommendations, which were developed by Dr. Colberg and a panel of experts, are the first that were created jointly with the two organizations. They incorporated evidence-based data from published clinical studies and trials into the recommendations.
“The presence of diabetes complications should not be used as an excuse to avoid participation in PA.”
“Research has established the importance of PA to health for all individuals, but these guidelines provide specific advice for those whose diabetes may limit vigorous or other forms of exercise,” Dr. Colberg says. “Both aerobic and resistance training have been shown to improve insulin action, blood glucose control, and fat oxidation and storage in muscle. Resistance exercise can enhance skeletal muscle mass. Exercise can also improve symptoms of depression and improve health-related quality of life. Patients with diabetes who are more fit and perform more PA have lower risks of all-cause and cardiovascular mortality.”
Recommendations to Remember
One of the key recommendations for patients with diabetes is to perform moderate-to-vigorous aerobic exercise for at least 150 minutes a week spread out at least 3 days during the week (Table 1). These patients should go no more than 2 consecutive days between sessions of aerobic activity. Aerobic activity alone, however, typically will not provide the full benefits of exercise. The recommendations indicate that resistance exercise (strength training) is an important component of managing diabetes. The most recent studies have reinforced the additional benefit of combining aerobic and resistance training. The recommendations also address using PA in patients with diabetes-related complications, such as cardiovascular disease, neuropathy, retinopathy, and kidney disease (Table 2).
Dr. Colberg says it is important to consider other health limitations in patients with diabetes. “Most people with type 2 diabetes don’t have sufficient aerobic capacity to undertake sustained vigorous activity for that weekly duration,” she says. “They may have orthopedic or other comorbidities that reduce their ability to meet this recommendation. Accordingly, healthcare providers need to bring patients up to speed slowly. Consider starting patients on brisk walking, gardening, or housework to motivate patients to become less sedentary. After that, ramp up the intensity and duration gradually as patients make progress.”
Physician Prescriptions Matter
In the past, many physicians have appeared to be unwilling or cautious about prescribing exercise to people with diabetes for a variety of reasons. Some are concerned because their patients have excessive body weight or fear that health-related complications may have a negative effect on patients. Others may be loath to supervise exercise in their patients due to issues surrounding costs, time, and adherence. Dr. Colberg says that physicians and healthcare providers need to change their thinking with regards to writing prescriptions for exercise and how to initiate supervised exercising, and that most individuals will not need to undergo exercise stress testing prior to starting a walking program. “The majority of people with diabetes can exercise safely, as long as certain precautions are taken,” she says. “The presence of diabetes complications should not be used as an excuse to avoid participation in PA. It’s paramount that PA be a conscious part of every person’s health plan, and physicians can take the lead by encouraging their patients by writing these prescriptions. Supervision isn’t always necessary, but it has been shown to increase compliance and improve glycemic control.”
The CDC predicts that one in three people in the United States will have diabetes by 2050, and diabetes and prediabetes will cost the nation nearly $500 billion annually by 2020. “The key to changing these trends is to work collaboratively to stop diabetes before it starts,” says Dr. Colberg. “Physicians and other healthcare providers must make every effort to get their patients with diabetes started with PA and increase intensity appropriately. Only with a collaborative effort will the burden of diabetes be slowed.”
Colberg SR, Sigal RJ, Fernhall B, et al. Exercise and type 2 diabetes. The American College of Sports Medicine and the American Diabetes Association: joint position statement. Diabetes Care. 2010;33:e147-e167. Available at: http://care.diabetesjournals.org/content/33/12/e147.full.
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American Diabetes Association. Standards of medical care in diabetes 2010. Diabetes Care. 2010;33(Suppl 1):S11-S61.