Your patient with type 2 diabetes wants to take a step exercise class. What recommendations will you offer? Another patient has diabetic retinopathy; which exercises are safest for her?
Answers to these and other questions about physical activity by patients with diabetes can be found in updated guidelines from the American Diabetes Association.1 Highlights of those recommendations follow.
EVALUATION BEFORE EXERCISE
Before a patient with diabetes starts an exercise program, a detailed history and thorough physical examination are required. Focus the evaluation on the symptoms of diabetes that affect the cardiovascular system, eyes, kidneys, feet, and nervous system.
Cardiovascular disease. Depending on the intensity of the exercise program a patient wishes to pursue, a graded stress test may be useful. If the exercise is low-intensity (less than 60% of maximal heart rate), such as walking, a stress test may be appropriate if the patient is at high risk for cardiovascular disease (Table).
Patients who exhibit nonspecific ECG changes while exercising or who have nonspecific ST-segment and T-wave changes on the resting ECG might benefit from radionuclide testing or an alternative test. In patients with known coronary artery disease, evaluate ischemic response to exercise, ischemic threshold, and propensity to arrhythmia. Assessment of left ventricular systolic function at rest and in response to exercise is a valid option in many cases.
Peripheral arterial disease. Signs and symptoms of peripheral arterial disease include intermittent claudication, decreased or absent pulses, cold feet, atrophy of subcutaneous tissues, and hair loss. Ischemic changes in the forefoot may occur even if dorsalis pedis and posterior tibial pulses are present. If you have any doubts concerning blood flow to the forefoot and toes during the physical examination, measure toe pressures and Doppler pressures at the ankle.
Retinopathy. If the eye examination reveals either no diabetic retinopathy or moderate nonproliferative diabetic retinopathy, then all but extreme activities, such as boxing and heavy lifting, are acceptable. For patients with active proliferative diabetic retinopathy, strenuous activity may cause vitreous hemorrhage or traction retinal detachment. Low- impact activities, such as swimming or stationary cycling, are acceptable, but jogging, weight lifting, and even trumpet playing should be discouraged.
Nephropathy. Advise patients with overt nephropathy to avoid strenuous activities; however, low- to moderate-level exercise is acceptable. These patients usually have a reduced capacity for exercise, and they tend to limit their physical activity.
Peripheral neuropathy. If a patient has lost protective sensation in the feet, repetitive weight-bearing exercise poses a risk of ulceration and fractures. If tests of deep tendon reflexes, vibratory sense, or position sense suggest peripheral neuropathy-or if the 5.07 (10-g) monofilament fails to indicate touch sensation-jogging, step exercises, and even extensive walking should be discouraged. Acceptable non-weight-bearing exercises include swimming, bicycling, rowing, chair exercises, and arm exercises.
Autonomic neuropathy. Cardiac autonomic neuropathy associated with diabetes has been linked to sudden death and silent myocardial ischemia. Patients with autonomic neuropathy are more likely to experience hypotension or hypertension at the start of an exercise program or after a vigorous session. Because these patients also have difficulty with thermoregulation, they should not exercise in hot or cold environments and should drink plenty of fluids regularly while working out.
PREPARATION FOR EXERCISE
Encourage patients with diabetes to engage in physical activities. Exercise is particularly important for patients who have or are at risk for type 2 diabetes (Box).
Young patients with good metabolic control can participate in most activities. Middle-aged or older patients-after proper screening-can engage in many activities that are not high-impact or high-resistance.
Recommend both a warm-up and a cooldown period (5 to 10 minutes each). During the warm-up, low-intensity aerobic activity is recommended. Stretching the muscles to be used in the exercise session is also advisable, either during or after the warm-up. During the cooldown, the heart rate is gradually lowered to its pre-exercise level.
Because trauma to the feet is a risk for patients with diabetes-particularly those with peripheral neuropathy-recommend silica gel or air midsoles. Polyester or polyester-cotton socks can help prevent blisters and keep the feet dry. Tell patients to monitor themselves for blisters and other injuries both before and after each session. They should always wear a visible diabetes identification bracelet or shoe tag while exercising.
Hydration, especially when exercising in the heat, is essential. Recommend that patients drink 17 oz of fluid 2 hours before exercising, and emphasize the need for early and frequent hydration during the session.
Although high-resistance weight training is not recommended for older persons with diabetes, nearly all patients can benefit from moderate weight-training programs. Such programs use light weights and a high number of repetitions to strengthen the upper body and maintain good muscle, bone, joint, and ligament health.
1. American Diabetes Association. Physical activity/exercise and diabetes mellitus. Diabetes Care. 2003;26(suppl 1):S73-S77.
2. Tuomilehto J, Lindstrom J, Eriksson JG, et al. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med. 2001;344:1343-1350.
3. Pan XR, Li GW, Hu YH, et al. Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance. The DaQing IGT and Diabetes Study. Diabetes Care. 1997;20:537-544.
4. Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346:393-403.