How to Control Diabetes With Exercise

Managing your diabetes care plan can help you maintain your health.


The three cornerstones in the treatment of diabetes are food, medications, and activity. Of these three, activity is often a first choice for the person who has diabetes. Moving toward a more physically active life is generally inexpensive, convenient, and easy and usually produces great rewards in terms of blood glucose control and a general feeling of well-being.


Whenever you actively use a muscle, you burn both fatty acids and glucose. During and after periods of activity, your falling glucose level is sensed by the beta cells in your pancreas, and they relax their output of insulin.

This gives your beta cells a break from excessive insulin production. In addition, the lower insulin levels signal your liver to empty its glucose reserves (glycogen) into the blood to supply the muscles with needed energy.

As physical activity continues, the liver converts amino acids, lactic acid, and fats into glucose to supply the muscles. If the activity continues long enough, even the body's fat cells get in the game. They compensate for the reduced fatty acid levels in your blood by converting their stored triglycerides into fatty acids.

When all of these steps are considered, it's easy to see why using your muscles is the perfect treatment for diabetes. It lowers blood glucose, lowers fatty acid levels in your blood, and reduces the workload of your pancreas. And, unless you are on a medication that can cause hypoglycemia, physical activity won't cause your blood glucose level to fall below normal the way some other diabetes treatments may.

In this article, you will learn how exercise can be incorporated into a battle plan for managing diabetes. First, though, you must consider some of the risks, which are outlined in the following section.


Assessing Exercise Risks

Becoming more physically active is not completely without risks for people with diabetes. On the other hand, remaining sedentary is no bargain, either; it does nothing to help your glucose control, your weight management, or your overall well-being. To gain the benefits of increased physical activity and minimize potential risks, you need to understand and evaluate those risks up front and take steps to prevent problems before they occur.


For people with diabetes who take medication or insulin, hypoglycemia is a concern. Whenever you are physically active, your muscles burn glucose. First, they gobble up the glucose they have stored as glycogen. As the activity continues, glucose from the blood pours into the muscles to supply their energy needs, lowering blood glucose levels. However, this march of glucose from the blood into the muscles doesn't end when the activity stops.


The body needs to refill the muscles' glucose storage tanks in preparation for future movement. As a result, a hypoglycemic reaction can occur not only during periods of activity but up to 24 hours later. Some people with diabetes who have frequently experienced hypoglycemia begin to associate any form of activity with a loss of glucose control.

For such individuals, a lack of glucose testing may keep them in the dark about how their body reacts to activity. As a result, they are unprepared for the low blood glucose level that can occur when they mow the lawn or when they take a brisk walk through the park. When such a low occurs, they may grab a handful of jelly beans to treat the low, only to find their glucose level skyrocketing as a result. So they take extra insulin or medication at dinner to treat the high, but the blood-glucose roller-coaster ride continues with another low before they go to bed.

These fluctuations create great confusion and frustration, leaving these individuals upset and scared. Activity, they may decide, is not worth the seemingly unpredictable swings in glucose. For such individuals, more frequent blood glucose testing can help them better understand their body's response to exercise and prepare for it by adjusting medication or food intake.

Heart Disease

Before you increase your activity level, you need to consider the possible presence of heart disease. As you've already learned, coronary heart disease is very common in people with diabetes, affecting perhaps as many as 50 percent of them. To assess your risk, you and your doctor need to take into account your age, your blood pressure, your blood fats, whether you have protein in your urine, the length of time you have had diabetes, and your family history.

So before you begin increasing your level of activity, consult your doctor and, if appropriate, have an exercise tolerance test. This test is done on a treadmill and reflects your heart's ability to work under stress. Your chances of having a positive result, indicating heart disease, increase with each risk factor you have. Even if you are at increased risk or have a positive test, you will likely still be able to increase your physical activity; you will just need to work more closely with your diabetes care team to set safe guidelines for activity and, perhaps, to determine if medications to lower your risk of heart trouble are in order.

Diabetes Complications

Before you increase your activity level, you need to account for any diabetic complications or related conditions that may be present. Some types of activity may not be wise for people with certain medical conditions. Any activity that includes straining, such as weight lifting, can dramatically increase blood pressure during the actual activity, further aggravating any hypertension that is present.

To lessen any potential problems, you need to have your blood pressure well controlled before you start increasing your activity level and especially before beginning an activity that involves straining. Proliferative retinopathy is also aggravated by straining, which increases the pressure within some of the weakened blood vessels of the eyes. Activities that require straining or that involve jarring or rapid head motions may also cause an acute hemorrhage in already weakened eye vessels.

For this reason, it is important to have your eyes examined for signs of retinopathy before starting an exercise program and have them rechecked annually. If you have significant nerve disease in your feet, you may not be able to feel injuries to your feet, the most common of which are blisters. This does not mean you cannot exercise, but it means that you need to have your feet checked by your doctor first and you must observe good foot care at home, including inspecting your feet for sore spots and minor injuries daily.

You'll also want to get expert advice on proper footwear for the activity and be sure that the footwear you choose is fitted properly to your feet.

Once you've factored in the risks, you can actually build your exercise program. That is the focus of our next section.


Exercise Guidelines

©2006 Publications International, Ltd. A doctor can help you form an exercise program.

The following guidelines can help you increase your activity level safely. Be sure to work with your diabetes care team, too, so they can monitor you and provide specialized advice for your specific situation.


First, be screened by your doctor for any possible problems before you start any type of activity. This exam should include a treadmill test for people with diabetes who fit certain criteria, an eye examination for proliferative retinopathy, a urine examination for protein, and a medical evaluation of your feet.


Whatever you choose, make sure the activities are enjoyable for you and take into account your abilities and condition. The activities don't even have to be "exercises" in the traditional sense, as long as they get you moving. Square dancing, taking your dog on long walks, riding your bike, gardening, and even walking the golf course all count.

Vary them so you don't get bored and fall prey to easy excuses. Choose some that can be done with others and some that can be done alone; some that can be done indoors, some that can be done outdoors; some that can be done when your schedule is light, and some that can be fit in when you're strapped for time.

Type of Activity

Once you've received your team's okay for exercise, you need to choose activities that fit your physical condition, lifestyle, and tastes. Many people with diabetes, especially those who have not been physically active for a while, find that easy, low-impact activities such as walking and swimming are perfect

Time, Intensity, and Duration

Begin each exercise session with a five- to ten-minute period of low-intensity warm-up activity (such as marching in place) and gentle stretching. The warm-up will prepare your heart for increased activity. The stretching will help you avoid tendon and muscle problems, which are common in people whose tendons have become brittle after years of high blood glucose levels.


Avoiding Glucose Problems During Exercise

To preempt problems with you glucose levels during exercise, there are a number of things you can do -- such as:

  • Plan your activity to follow a meal so that it can help lower the increased blood glucose level that follows eating.
  • Check your blood glucose 30 minutes before and then just prior to activity. This way you can see which direction your glucose level is heading and anticipate a low in time to take preventive action.
  • If you are at risk for hypoglycemia, plan for a possible hypoglycemic episode. Carry glucose tablets with you; if symptoms of low blood glucose develop, stop the activity immediately and use the fast-acting glucose.
  • If you manage your diabetes with insulin, know the peak time of your insulin and plan your activities accordingly. Avoiding the times when your insulin is peaking and at its strongest will help you prevent hypoglycemia.
  • When injecting insulin, avoid the muscle areas that you will be using during the activity. For example, if you will be playing tennis, avoid using your racket arm and even, perhaps, your legs for your injection at the meal prior to your game. Most people find the abdomen or the buttocks work best before exercise.
  • When planning to be extremely active, test your glucose level prior to getting started. If your blood glucose is near normal but you have the potential to develop hypoglycemia, you will need to eat prior to the activity. (If you take insulin, you will either need to eat prior to the activity or lower your insulin dose.)
  • If your blood glucose before the activity is more than 250 mg/dl, check your urine for ketones. If they are present, activity will actually cause your blood glucose level to increase. An elevated glucose level and positive ketones indicate that your diabetes is uncontrolled and you need to contact your diabetes care team for advice immediately.
  • Monitor your glucose during exercise to see what effect activity has on you. Check it every half hour during exercise and again when you are finished.
  • Be sure to drink plenty of fluids. Sweating means you are losing fluids that need to be replaced. Water is usually a great choice.
  • If, during any activity, you ever experience shortness of breath, chest pain, or leg cramps that go away with rest, contact your doctor immediately. These are all possible signs of blocked arteries and require an evaluation by your doctor.
  • If you repeatedly experience episodes of hypoglycemia during and/or after increased levels of activity, you should contact your doctor and discuss the possibility of a change in your medications.

Being active needs to be fun. Otherwise, you're much less likely to stick with an active lifestyle. Choose your activities accordingly, then go out and play at least a little every day.