The presence of autonomic neuropathy may limit an individual’s exercise capacity and increase the risk of an adverse cardiovascular event during or after exercise. Cardiac autonomic neuropathy (CAN) may be indicated by resting tachycardia (>100 beats per minute), orthostasis (lowering of systolic blood pressure >20 mmHg upon standing), or other disturbances in autonomic nervous system function involving the skin, pupils, or gastrointestinal or genitourinary systems. Sudden death and silent myocardial ischemia have been attributed to CAN in diabetes [27]. Resting or stress thallium myocardial scintigraphy is an appropriate noninvasive test for the presence and extent of macrovascular coronary artery disease in these individuals. Hypotension and hypertension after vigorous exercise are more likely to develop in patients with autonomic neuropathy, particularly when starting an exercise program. Because these individuals may have difficulty with thermoregulation, they should be advised to avoid exercise in hot or cold environments and to be vigilant about adequate hydration. Adequate hydration prior to exercise is recommended (e.g., 17 oz of fluid consumed 2 h before exercise). During exercise fluids should be taken early and frequently in an amount sufficient to compensate for losses in sweat. The reader is referred to Chap. 6 of this textbook for specific detailed scientific base research regarding adequate hydration recommendations.

Evaluation of PAD is based on signs and symptoms, including intermittent claudication, cold feet, decreased or absent pulses, atrophy of subcutaneous tissue, and hair loss.

The eye examination schedule should follow the American Diabetes Association’s Clinical Practice Guidelines [28]. For patients who have proliferative diabetic retinopathy (PDR) that is active, strenuous activity may precipitate vitreous hemorrhage or traction retinal detachment. High-volume moderate-resistance exercise has been shown to result in fluctuation in systolic blood pressure to generally less than 180 mm and is probably safe. However, athletes with proliferative retinopathy should exercise caution when attempting exercises that involve Valsalva maneuvers or sudden jarring motions.

On the basis of Joslin Clinic experience, the degree of diabetic retinopathy has been used to stratify the risk of exercise and to individually tailor the exercise recommendations. Table 15.2 noted below provides viable considerations for activity limitations in diabetic retinopathy clients.

Many patients with long-standing diabetes mellitus and no proteinuria at rest will develop significant proteinuria after an intensive exercise session. Active individuals should be instructed not to engage in intensive activity prior to assessment for proteinuria. The predictive value for such exercise-related increments of urinary protein on the subsequent development of renal disease is still undetermined.

Athletes with diabetes do not have a higher incidence of end-stage renal disease in cross-sectional studies. Specific exercise recommendations have not been developed for patients with incipient (microalbuminuria >20 albumin excretion) or overt nephropathy (>200 mg/min) [29]. Patients with overt nephropathy often have a reduced capacity for exercise which leads to self-limitation in activity level. Although there is no clear reason to limit low to moderate intensity forms of activity, very high-intensity or strenuous exercises should probably be discouraged as the hemodynamic consequences are likely to be detrimental. Many athletes use dietary supplements very high in protein and these should be avoided in the presence of renal disease as high protein intake may accelerate loss of renal function.

A standard recommendation for athletes with diabetes is that exercises include a proper warm-up and cooldown period. A warm-up should consist of 5–10 min of aerobic activity (walking, cycling, etc.) at low-intensity level.

After a short warm-up, muscles should be gently stretched for another 5–10 min. Following the activity session, a cooldown should be structured similarly to the warm-up. The cooldown should last about 5–10 min and gradually bring the heart rate down to its pre-exercise level. Many exercise-related arrhythmias occur during the postexercise recovery period and it has been suggested the high levels of FFA that occur when exercise is abruptly terminated may contribute. A cooldown period will blunt this response.

There are several considerations that are particularly important and specific for the individuals with diabetes.

The recommendations given below may be useful for previously sedentary patients with diabetes who wish to initiate serious programs of physical activity. These exercise prescription categories include the following considerations: