Exercise and diabetes—small steps to success
Physical activity can help manage weight; lower BP, low-density lipoprotein cholesterol, and triglycerides; increase high-density lipoprotein cholesterol; improve muscle tone and bone strength; decrease anxiety; and improve overall health. Benefits specific to patients with diabetes include improved glycemic control, increased insulin action leading to decreased insulin resistance (particularly in patients with type 2 diabetes), decreased HbA1C, increased cardiovascular fitness, and an improved overall mental health outlook. Because of these identified benefits, it seems reasonable to recommend that patients with diabetes follow the physical activity guidelines for the general population if not contraindicated.
The U.S. Department of Health and Human Services physical activity guidelines suggest that adults older than age 18 perform 150 minutes/week of moderate exercise or 75 minutes/week of vigorous aerobic activity or an equivalent combination of the two. For those older than age 65 or those with disabilities, either following adult guidelines or remaining as physically active as possible has been suggested. The guidelines recommend muscle strengthening activities that involve all major muscle groups to be carried out 2 or more days each week.
To add to this, the American Diabetes Association (ADA) and the American College of Sports Medicine formulated a joint statement that emphasizes the positive benefits of exercise for patients with type 2 diabetes.
Choosing an exercise program
Physical activity has long been believed to be an important way to control and manage weight. Weight management is defined as calories eaten from food and drink being equal to calories burned at rest and with physical activity. Whichever method of weight management your patient chooses, it's important to remember to encourage a patient who loses weight to continue working on ways to keep it off.
When choosing an exercise program that works for your patient, it's essential to discuss types of exercise and which activities fit the individual's lifestyle. Aerobic, anaerobic, and resistance exercises can be recommended when appropriate. Patient age and previous physical activity level should be considered.
Aerobic exercise is steady and increases the heart rate to at least 70% of maximum, while increasing the use of oxygen. Aerobic exercise burns glucose and fat and provides the greatest benefit for blood glucose and weight management. Suggested exercises might include walking, bicycling, and swimming.
Anaerobic exercise doesn't use oxygen to help release energy from the fat cells but is known to build muscle tissue. Anaerobic means without air, and refers to the energy exchange in living tissue that's independent of oxygen. Anaerobic exercise is brief, high-intensity activity during which anaerobic metabolism is taking place in muscles. It provides a number of health benefits, such as improving muscle bulk, preventing osteoporosis, and decreasing fat composition in the body. Examples of anaerobic exercise include weight lifting, sprinting, and jumping; any exercise that consists of short exertion, high-intensity movement is an anaerobic exercise. These activities can't last long because oxygen isn't used for energy and a byproduct called lactic acid is produced. Although anaerobic exercise has benefits, it doesn't lower insulin resistance or significantly lower BP or cholesterol. It's important to remember that some anaerobic exercises increase intraocular pressure and should be avoided by patients with preexisting diabetes complications.
Resistance exercise takes place when a muscle contraction is opposed by an outside force to increase strength or endurance. Using weights may carry out a resistance exercise. These exercises are believed to improve the action of insulin and bring about metabolic improvements. Once again, patients need to be cautioned about extensive resistance exercising if they have preexisting complications.
Exercise has been described as light, moderate, or strenuous in nature. Light exercise doesn't make a patient breathe heavier, but the pulse rate may increase slightly. Moderate exercise involves noticeably heavier breathing, with a pulse frequently above 100 beats/minute. Strenuous exercise involves rapid breathing, with a pulse rate above 160 beats/minute.
When considering which level of exercise is correct for your patient, it's prudent to remember that what's considered light exercise for one patient may be different for another, depending on the person's level of fitness. The effect of any exercise on blood glucose depends on the time spent on the activity. It's also important to note if your patient is taking insulin because a change in the management plan may become necessary.
Previous guidelines suggested that before recommending a program of physical activity, patients should be assessed for conditions that might contraindicate certain types of exercise or predispose them to injury. Uncontrolled hypertension, severe autonomic or peripheral neuropathy, a history of foot lesions, and unstable proliferative retinopathy are several complications to be considered. The ADA consensus on evaluation of patients with diabetes before beginning an exercise program has concluded that screening an asymptomatic patient isn't recommended, but clinical judgment should be used, as appropriate. Certainly, high-risk patients should be encouraged to start with short periods of low-intensity exercise and increase the intensity and duration slowly.
For example, if a patient with hypertension were to choose weight lifting instead of an aerobic exercise modality, such as walking, worsening of hypertension could occur. Using the lower extremities causes smaller increases in systolic BP than activities involving the upper extremities.
When discussing exercise with your patient, a few concerns should be considered:
- In the presence of proliferative diabetic retinopathy or severe nonproliferative diabetic retinopathy, vigorous aerobic or resistive exercises may be contraindicated because of the risk of triggering a hemorrhage or retinal detachment.
- Decreased pain sensation in the extremities results in an increased risk of skin breakdown, infection onset, and joint deformity and instability caused by Charcot disease. Previously, patients with neuropathy were advised to engage in non-weightbearing activities. However, it's now believed to be more appropriate to consider moderate-intensity walking because it hasn't been proven to cause an increase in foot ulcers.
- Autonomic neuropathy can increase the risk of exercise-induced injury through decreased cardiac responsiveness to exercise, postural hypotension, and gastroparesis (the reduced ability of the stomach to empty its contents), which can predispose a patient to hypoglycemia resulting from the neuropathy.
- Physical activity can increase urine protein excretion. It's believed that restrictions for patients with diabetic kidney disease aren't warranted because vigorous exercise hasn't been proven to be related to its progression. One might also consider the possibility of exercising with diabetes as precipitating or exacerbating cardiovascular disease such as arrhythmias, excessive increase in BP (exercise should be performed at an intensity that avoids a hypertensive response), angina pectoris, and myocardial infarction.
Pregnant patients with diabetes who perform anaerobic exercises have a more rapid diversion to fat metabolism. This results in an increased risk for diabetic ketoacidosis (DKA). Concentrations of free fatty acids and ketones reach higher levels in pregnant women than in nonpregnant women, again increasing the risk of DKA.
Elderly patients with diabetes should plan exercise to accommodate preferences, functional capacity, and coexisting cardiovascular diseases. Physical limitations can be accommodated through such activities as stationary biking, swimming, or water aerobics. The older patient with diabetes should be encouraged to exercise with others, take rest periods, remain safe, and be alert to the possibility of hypoglycemia along with the timing for exercise.
Asthma and diabetes have been linked. The common denominator appears to be inflammation. Asthma is treated with steroids and these steroids may also increase the risk of diabetes complications secondary to hyperglycemia. A person may experience exercise-induced bronchospasm (EIB) during or after exercise. EIB makes it difficult to exercise so many people avoid physical activity and this lack of exercise can lead to other problems, such as diabetes.
Getting your patient started
The best place for your patient to start is to choose an activity that's enjoyed and is convenient. Patients will be more likely to stay with a program that they like and one that isn't too difficult to do. Remember to stop and consider what might be stopping your patient from enjoying exercise.
Share the following tips with your patient:
- Consider having a glucose meter available. Test blood glucose before and during exercise, if necessary.
- Go easy on yourself. Start slow, take precautions, set small goals, and measure them so you can be successful. Remember to think long term, but start small.
- Learn how often, how long, and how hard to perform a physical activity.
- Increase physical activity gradually.
- Select appropriate footwear to protect your feet. Examine your feet before and after each exercise session.
- Plan to exercise 1 to 3 hours after eating.
- Wear a medical-alert bracelet that indicates that you have diabetes.
- Have a list of contacts available.
- Dress in layers in case you get too warm.
- Drink water before, during, and after your activity.
- If you feel sick, don't exercise until you're feeling better.
- Monitor for the presence of ketones, a sign of faulty carbohydrate metabolism in uncontrolled diabetes, and don't exercise if present.
- Don't allow yourself to become demotivated.
- Be creative in finding ways and time to exercise. Consider walking the steps instead of taking the elevator, and walking to chores instead of driving a car.
Suggestions for small steps to success
When educating your patient about the benefits of undertaking an exercise program, consider the following:
- Remember the benefits of a good stretch: push, pull, and lift your way to success.
- Make a strong start by beginning strength-training activities, if permitted. A simple activity such as lifting a soup can while walking around the house could turn out to be a beneficial exercise for the muscles.
- Start off on the right foot and walk your way to a healthier life. Consider purchasing an inexpensive pedometer just to see how many steps you're already walking.
- Substitute activity for inactivity. Consider adding something simple, such as stretching or doing yoga, while watching TV.
- Get in the swim. Water is an equalizer; it supports arms and legs, and provides gentle, natural resistance that can help build muscle strength.
- Find the support you need to remain motivated.
During exercise, and often for hours afterwards, blood glucose levels go down. Hypoglycemia is one of the most common emergencies in patients with diabetes. With the use of more intense insulin regimens, improved blood glucose control often comes with the risk of more frequent hypoglycemia.
Hypoglycemia is generally classified as low, moderate, or severe. The designated term is often based on the specific symptoms of low blood glucose that the patient is experiencing. Symptoms that patients experience vary, so relying on blood glucose readings alone isn't entirely significant.
When a patient experiences mild or moderate symptoms of low blood glucose, the symptoms are often manifestations of the sympathetic nervous system's response to the low blood glucose level. Signs, such as shakiness, sweating, rapid heartbeat, headache, feeling hungry, nervousness, anxiety, and lightheadedness, are often dependent not only on low blood glucose but also on how quickly the patient's blood glucose level is dropping. Signs of severe hypoglycemia can include unconsciousness, seizure activity, confusion, and inappropriate behavior and/or conversation.
Hypoglycemia is rare in patients with diabetes who aren't being treated with insulin or insulin secretagogues, and therefore no preventive measures for these patients are generally suggested.
For patients taking insulin and/or insulin secretagogues, physical activity can cause hypoglycemia if the medication dosage or carbohydrate consumption isn't altered. For these individuals, it's suggested that added carbohydrates should be ingested if preexercise blood glucose levels are below 100 mg/dL. Typically, patients would be instructed to take 15 g of carbohydrate before exercising. Suggestions could include 4 oz of juice, 3 to 4 glucose tablets, or 4 oz of regular soda. A repeat blood glucose reading is advised after this treatment. If a reaction is severe enough that unconsciousness occurs, an injection of glucagon can be given to change stored glycogen to glucose. It will reverse hypoglycemic reactions and increase the use of fats and amino acids for energy production. Of course, educating a family member or significant other should be a part of this treatment plan.
Patients with type 1 diabetes deprived of insulin for 12 to 48 hours can experience hyperglycemia and should be advised that vigorous exercise should be avoided in the presence of ketones. Although it isn't necessary to cancel exercise in the face of hyperglycemia alone, it's generally advised to forego exercise until the patient feels better and the urine and/or blood is free from ketones.
Can patients with diabetes really exercise safely?
Clinical intervention designed to implement exercise patterns suggests that participation is higher when patients are made aware of what constitutes an unhealthy lifestyle and when they perceive themselves as being more susceptible to the complications of diabetes that can result from inactivity. Although physical activity is vitally important for managing diabetes, many of the individuals who begin formal exercise programs don't sustain these behaviors beyond 6 months.
Complications of diabetes are inevitable. Regardless of pharmaceutical interventions, unless lifestyle interventions are negotiated, initiated, and maintained through patient education, training, and empowerment, little success will be achieved. Providing ongoing support is one of the main ingredients in the recipe of helping patients maintain gains achieved through education.
Incorporating physical activity into one's lifestyle has been identified as one of the content areas to be included in a diabetes self-management education (DSME) program. DSME is the ongoing process of facilitating the knowledge, skill, and ability necessary for diabetes self-care. DSME is an essential and effective aspect of diabetes healthcare. All patients with diabetes should be offered individualized DSME on an ongoing basis.
Healthcare professionals need to know their patients. We must stop and ask questions. Give your patient the opportunity to choose activities that he or she enjoys. Remember, diabetes isn't a “one size fits all” disease. If we aren't open to our patients' thinking and feelings, they'll continue to come up short.