DIABETES AND EXERCISE | Added: 12, August 2017


Do people with diabetes benefit from exercise?

Yes, people with diabetes benefit from exercise in many ways. In particular, exercise-or any activity that keeps a person moving-helps with blood glucose control. This is because when muscles are used, fatty acids and glucose are burned. Thus, during and after exercise or activity, the body’s glucose decreases, which means the pancreas’s beta cells decrease the release of insulin, reducing the workload of the pancreas. The lower amount of insulin signals the liver to empty its glucose reserves (glycogen) into the bloodstream for the muscles to use as energy. Unless a person is on diabetes medication that can cause hypoglycemia, physical activity can help keep blood glucose levels in control. It also can improve insulin sensitivity, lower blood pressure and fats, and help with cardiovascular (heart in particular) wellness.

When does a person with diabetes not benefit from exercise?

Some exercises are not considered appropriate for a person with diabetes under certain conditions. For example, certain activities that include straining, such as weightlifting, can increase a person’s blood pressure during the activity. If an individual already has hypertension (high blood pressure), such activities can aggravate the condition. In addition, if a person has diabetic retinopathy, it also may be aggravated by straining exercises-and even those activities that include jarring or rapid head motions. If a person has peripheral neuropathy in the feet, he or she can still usually exercise but must conscientiously check his or her feet as nerve damage may cause the person not to feel an injury. Overall, the best course of action for a person with diabetes who wants to do any type of physical activity is to discuss it with a health care provider.

What is more important for a person’s health-losing weight or exercise?

Both losing weight and exercise are important for many people with and without diabetes. But there is an interesting bias toward losing weight and exercise: when some people exercise and notice that their weight does not change, they stop, thinking it does no good. In reality, people who exercise are reducing their risk of heart disease and stroke. In fact, most experts agree that exercising may be more important to a person’s health than losing weight. They think of it as exercising for health, not for becoming thin.

In one study, more than 25,000 men and 7,000 women were tracked for eight years, with the researchers testing in particular body weight and fitness level. They found that for most people, an active lifestyle-which can include walking, biking, weight-bearing exercises, and so on-actually overrides certain risk factors for heart disease, such as genetics, high cholesterol, smoking, or even being overweight. Men and women who were moderately to highly fit, no matter what their risk factor(s), had the lowest death rates from all causes. This is not to say that being overweight or obese is all right for a person’s health. (For more about obesity, see the chapter “Diabetes and Obesity.”) Almost all health care professionals agree that being overweight or obese increases a person’s chances of developing heart disease, diabetes, and other ailments. In fact, the more extra pounds a person carries, the greater the chance of illness, especially if the person is sedentary.

Don’t be discouraged if you are trying to lose weight but the scale shows the same result. You are still boosting heart health, and if you gain muscle and lose fat, the total weight might seem the same.

Is there a double benefit to exercise for diabetes and the heart?

Yes, there is apparently a double benefit to exercise, especially if a person has diabetes and has (or has a potential for) heart disease. For example, in a recent study, 4,000 nurses between ages 40 and 65-all with diabetes-reduced their chances of developing heart disease by 28 percent just by having a regular walking regime. If someone exercised more vigorously, then the risk went down by another 5 percent.


What should a person with diabetes be aware of when exercising in hot or cold weather?

If a person with diabetes exercises in hot or cold weather, depending on the situation and level of physical activity, low blood glucose levels can result. For example, if people with diabetes exercise in the heat, causing them to sweat profusely, then they may become dehydrated. This will cause a rise in their blood glucose levels and, in turn, make them urinate frequently, producing even higher glucose levels. In addition, if people use insulin injections to treat their glucose levels at this time, their dehydration causes a reduction of blood supply to the skin, resulting in less of the injected insulin being absorbed. (For more about weather and the outdoors, see the chapter “Coping With Diabetes.”)

What are some temperatures considered safe for exercise by a person with diabetes?

There are some general guidelines when it comes to walking and exercising in the great outdoors, depending on where you live, especially during the hottest and coldest times of the year. For example, when it comes to walking, for most people (with or without diabetes) the following applies: 90°F (32°C) and below, most people can walk (as long as the humidity is not high); 91–104°F (33–40°C), proceed with caution; 105–129°F (40– 54°C), consider walking indoors in air conditioning, such as in a mall; 130°F, stay inside. Of course, not all of these numbers are definitive. Many times, with a temperature of 90°F (32°C), the humidity is around 75 percent, which makes it very difficult to walk or do most any exercise (unless the person is used to the conditions and as long as he or she consumes fluids, takes many breaks, and dresses to fit the weather). As with any exercise, a bit of common sense goes a long way.

Is it safe for a person with diabetes to walk (or exercise) in the warmer weather?

In most cases, yes, it is fine for a person with diabetes to walk in the warmer weather. But there are some caveats. First, bring a water bottle on the walk, as dehydration is especially dangerous for people with diabetes because it can increase the blood sugar levels. Some snacks may also serve to prevent low blood sugar if needed or whatever a person knows works for him or her in treating low blood sugar. For example, some people with diabetes carry glucose tablets or gels with them, especially if they are prone to low blood sugar levels whether they exercise or not. (For some people with diabetes, it is always necessary to carry a glucagon kit; for more information about glucagon kits, see the chapter “Taking Charge of Diabetes.”) Another suggestion is to make insulin adjustments as needed; people with diabetes can ask their health care provider or diabetes educator for the best way to adjust their insulin according to their specific needs. Probably the best practice when exercising in warmer weather is to test blood glucose levels more frequently, which will help a person with diabetes take appropriate action-immediately, if necessary-to keep glucose levels stable.

What are some of the best times for a person with diabetes to walk or exercise when it’s hot?

Most people agree-even those who do not have diabetes-that there are better times to walk than when it’s too hot. Some people exercise early or late in the day, when the temperatures are cooler. Still others get their physical activity in air-conditioned places, such as a gym or their own home.

Is it safe for a person with diabetes to walk (or exercise) in colder weather?

There are many precautions to take before venturing out to walk for exercise in the lower temperatures. In particular, cold-weather workouts can be risky for people with diabetes. This is because walking in the cold burns more calories to increase the body’s warmth, so it increases the demands for blood sugar (glucose). This increased demand may be fine for people without diabetes, but for a person with diabetes it can lead to hypoglycemia, meaning too-low blood sugar.

Another concern is frostbite. This is because people with diabetes have poor circulation in their extremities, making it easy not to feel too cold-and frostbite can affect the feet and hands. A person with diabetes who loses feeling in the hands or feet should get indoors as soon as possible. Another possible condition is cyanosis-when skin looks blue-which is the first sign of frostbite. If this occurs, the person with diabetes should see a doctor immediately.


What blood glucose goals should a person with diabetes have when exercising?

The biggest goal for people who exercise and have diabetes is to maintain their blood glucose levels during the activity. In particular, they should avoid becoming hypoglycemic (low blood glucose) before, during, and after exercise. The best way is to check blood glucose levels often. According to the Joslin Diabetes Center, this means checking blood glucose before, halfway through, and after exercise. For someone just beginning a certain exercise activity, this data becomes important, as it will help him or her learn the impact of that exercise on blood glucose levels. Overall, the person’s health care professional or diabetes educator can make suggestions to keep blood glucose better balanced during physical activity.

What are some suggestions to maintain blood glucose levels before exercising?

According to the Joslin Diabetes Center, if a person with type 2 diabetes is on oral medications, his or her blood glucose level should be 90 milligrams per deciliter (mg/dl), or slightly above, before exercising. (Note: A person with type 2 diabetes with a blood glucose level of 400 mg/dl or higher should avoid all exercise and contact a health care provider for ways to lower the blood glucose.) Another suggestion is to contact the health care professional before starting any exercise program to make sure the medication being taken will not lead to hypoglycemia (some diabetes medications can increase the risk of hypoglycemia). Someone with type 1 diabetes who is taking medication and insulin is more at risk for hypoglycemia-so it is suggested that the blood glucose target level be 110 to 140 mg/dl or above before starting exercise. And people with either type 1 or type 2 diabetes should also pay attention to how various exercises affect their glucose levels: for example, how aerobic exercise will result in different glucose levels than resistance training.

Exercise is vital in controlling diabetes, and monitoring blood sugar becomes even more important when establishing a routine. Check your glucose before, during, and after exercising, just in case.

What should a person with type 1 diabetes know about ketones and exercise?

If possible, a person who has type 1 diabetes should talk to a health care professional about how to check for ketones in the blood before physical activity, especially if it is rigorous activity. If there are ketones, it is best to avoid the exercise and ask the health care provider how to lower ketone levels in order to do any physical activity. If there are no ketones, it is suggested that the person perform low-to-moderate physical activity.

Do muscle-strengthening exercises help women prevent type 2 diabetes?

Yes, according to a study conducted in 2014, women who do exercises that strengthen muscles seem to have a lower risk of developing type 2 diabetes. The study included 100,000 women between ages 36 and 81. The researchers found that women who practiced yoga, lifted weights, or did stretching or toning exercises had a lower risk of developing the disease than participants who did not perform muscle-strengthening exercises. They also found that 60 minutes of muscle-strengthening exercises per week, along with 150 minutes of aerobic exercise such as running, walking, or cycling, had an even greater benefit.


Why should people with diabetes be careful when they buy shoes and sneakers?

It does pay, so to speak, for a person with diabetes to pay attention when shopping for shoes and sneakers. This is because the feet are one of the weakest points in anyone with diabetes. Many people with diabetes walk for exercise, so here are some shopping tips that may help. For example, people can shop at the end of the day, when their feet are largest (the foot can be almost a half size larger by afternoon than in the morning). If possible, they should have their feet measured in order to obtain the best shoe size and fit. They should wear the socks they wear while exercising or walking, and when trying on a shoe, make sure there is plenty of room (experts say at least a finger’s width) beyond the end of the toes (and measure while standing, not sitting). Not all shoes that are good for a person with diabetes will be stylish or trendy. But footwear that fits usually means fewer problems with the person’s feet. That is why most health care professionals-especially those who deal with foot care-agree that when it comes to diabetes and a person’s feet, it is better to have function over style.

When should a person replace his or her walking shoes?

In general, it is recommended to replace walking shoes every 500 to 700 miles (although this number varies depending on the organization recommending shoe replacements) in order to keep a person’s feet, ankles, knees, and lower back healthy and free of injury. Of course, most people don’t count how many miles they travel in a pair of walking shoes or sneakers. So the rule of thumb is that if the heel shows wear, or the upper part of the shoe looks as if it has been pushed to one side, or if, of course, the shoe’s seam is ripped or the upper part of the shoe is falling apart, then it is time to get new walking shoes. People with diabetes should look for two pairs of walking shoes to keep on hand, not just one. That way, if the shoes become wet, they can use the dry shoes. Wet shoes often cause blisters and can promote or exacerbate athlete’s foot, both of which are dangerous for a person who has diabetes. (For more about feet, blisters, and athlete’s foot and the diabetic, see the chapters “How Diabetes Affects Bones, Joints, Muscles, Teeth, and Skin” and “How Diabetes Affects the Nervous System.”)

Why are socks so important to a person with diabetes who exercises?

For most people with diabetes-type 1, type 2, and other types-exercise is an important part of their daily routine, especially to help manage weight and control glucose levels. Whether it is walking, hiking, or lifting weights at a gym, finding the right socks for exercise is especially important for people with diabetes. The major reason is that the feet can experience nerve damage (neuropathy), a problem for an estimated 50 percent of all people with diabetes. This causes a loss of sensation in the feet, meaning that a blister or wound will not be noticed until it worsens. Thus, health care professionals offer the following tips for socks for people with diabetes (see below for shoe recommendations):

Believe it or not, even getting the right kind of socks can be important when you are exercising. Padded, good-fitting socks made for diabetics are the best choice.

Get a fitted pair, not shapeless tube socks that can bunch up and cause chafing and blisters. The best fabric for socks is acrylic; the fibers wick sweat away from the feet and keep them drier than do cotton socks. This means the person will have fewer blisters and foot infections.

Find socks that are specifically for people who have diabetes. Some hints about the best types of socks can be found on the American Podiatric Medical Association website at www.apma.org.

Try to get padded socks but not so padded that there is little room for the foot. A too-tight fit in the shoe can cause foot blisters and infections. And make sure the tops of the socks are not too tight, as they may restrict the blood flow to the legs and feet.

Why are shoes so important to a person with diabetes who exercises?

Because exercise is an important part of the daily routine for most people with diabetes, having the right shoes becomes very important. Whether it is walking, hiking, or lifting weights at a gym, finding the right shoes can be the most important part of the exercise. This is because the feet can experience nerve damage (neuropathy), causing a loss of sensation in the feet. If the shoes do not fit, then a blister may not be noticed. Thus, many health care professionals offer the following tips for finding the best shoes for people with diabetes (see above for sock recommendations):

Try visiting a local, more personal, specialty shoe store where the staff would know more about the best shoes (including for a person with diabetes) and would offer more personal attention.

The best time to shop for shoes is at the end of the day. This is because a person’s feet swell throughout the day and are the largest toward evening. Shopping toward day’s end will help one choose the correct size.

Many people’s feet are not the same size. If so, see whether the shoe store staff can suggest ways to make both shoes fit correctly, without chafing or causing blisters.

Look for shoes that are comfortable almost immediately, with no pinching or pressure. The shoes should also be well padded and should not rub the foot. Also look for a large toe box, or the front of the shoe, so the toes can wiggle easily but without so much room that the foot slips around (that can cause chafing).

Unfortunately, not all of the best shoes for a person with diabetes will be trendy or showy. High heels, for instance, can injure women’s feet.

Finally, don’t be afraid to replace walking/exercise shoes regularly. It is suggested that most walkers buy new shoes every 500 to 700 miles, which translates to about every six months to a year if a person walks two miles five times a week.