American Diabetes Association Complete Guide to Diabetes: The Ultimate Home Reference from the Diabetes Experts

CHAPTER 11

Physical Activity and Exercise

• Getting Started

• Stages of Exercise

• Types of Physical Activity and Exercise

• Special Precautions for Physical Activity and Exercise

• Physical Activity and Your Blood Glucose

The benefits of regular exercise are undeniable. Physical activity improves overall health, helps protect against heart disease, and fights depression. It can increase your energy level and help you lose or maintain weight.

You’ll hear the terms “physical activity” and “exercise” throughout this chapter. You may wonder about the difference between these two expressions.

“Physical activity” refers to any activity that gets you moving and helps you burn energy. It could include the time you spend walking from your car to the office, climbing a flight of stairs, or raking leaves in the yard. “Exercise” generally refers to a specific, planned physical activity such as swimming, biking, or running. Both physical activity and exercise are wonderful ways to get in shape and stay healthy.

Aerobic exercise—the kind that makes you breathe harder—gives your heart and lungs a good workout. It makes your heart pump harder and gets the blood flowing through even your smallest blood vessels. This is important for anyone, especially for people with diabetes, who are at greater risk for heart disease. Physical activity can decrease bad cholesterol and increase good HDL cholesterol.

Physical activity also clears glucose from your blood, which is a real benefit for people with diabetes. It seems to make muscles and other tissues more sensitive to insulin, so less insulin is needed to move glucose out of the blood and into muscle cells. People with diabetes who use insulin may need to use less insulin or eat more on the days they work out. People with type 2 diabetes who exercise regularly may be able to manage their blood glucose without insulin or diabetes pills or they may just take less medication.

Benefits of Physical Activity and Exercise

• It improves blood flow, muscle tone, and flexibility

• It can help prevent heart disease and other health problems

• Decreases bad LDL cholesterol and increases good HDL cholesterol

• Improves mild to moderate high blood pressure

• It can help you look and feel better

• Physical activity can help you handle stress

• It can help improve your quality of sleep

Getting Started

One of the first things you’ll need to do is meet with your health care team. You should have a complete medical history done and a physical examination, if you haven’t done so recently. You will want to talk to your team about adjusting your eating plan and your insulin or oral diabetes medication to keep your blood glucose levels on target. Also, you may want to discuss the types of physical activity you’re considering.

Make sure that you don’t have any health problems that could keep you from exercising safely. If you are going to begin a regular exercise program, you need to be tested for evidence of retinopathy and cardiac disease and any problems with kidney or nerve function. If you have any of these problems, it doesn’t necessarily mean you can’t exercise, but you may need to treat these problems before you start working out regularly.

Physical Activity Topics to Discuss with Your Doctor

• How can I safely be more active?

• What times of the day are best for me? How long should my session last?

• How hard can I safely exercise?

• Is it more effective to stick to the same routine each time, or can I vary the length and intensity of my workouts?

• How can I monitor how hard I exercise? Should I count my heart rate? What’s my target heart rate? How often should I monitor?

• Are there types of physical activity I should avoid?

• Are there symptoms of hypoglycemia or heart disease that I should look out for?

• Any special precautions I should take?

• Do I need to take less insulin or other medications or change my injection site before I work out?

• Do I need to modify my meal plan?

• Will diabetes pills or other medications affect me differently if I work out?

In some cases, your doctor may refer you to an exercise physiologist to do a more thorough examination of your health. An exercise physiologist will do a variety of tests to determine your fitness level, including measuring your strength, flexibility, endurance, and body fat. The physiologist may also give you a treadmill stress test, in which you walk on a treadmill while your blood pressure and heart function are monitored. The test detects how a workout affects your heart activity and blood pressure.

When You Might Need a Treadmill Stress Test

• If you are about to begin a moderate- or high-intensity exercise program.

• If you are over 35 and have heart disease, cardiovascular risk factors, vascular complications, or nerve disease.

You’ll need a referral to see an exercise physiologist if your doctor does not perform the test. Many hospitals and universities have wellness programs for people with diabetes or rehabilitation programs for people who have had heart surgery or stroke. These programs offer stress tests by exercise physiologists and a full range of exercise options to get you started in a medically supervised environment.

Stages of Exercise

The best rule for a safe workout is to listen to your body. You should not have too much fatigue, pain, or shortness of breath. Doing too much too fast can lead to injuries or even life-threatening situations. You’ll want to warm up before and cool down after any exercise.

Warm Up

Warming up before you exercise reduces your risk for pulled muscles and other injuries.

• Always warm up for 5–10 minutes before any physical activity.

• Move slowly at first, using low-intensity easy movements to warm up your muscles.

• Gently stretch for 5–10 minutes, without any bouncing. For example, if you plan to walk for exercise, walk at an easy or comfortable pace for 5–10 minutes, then stop and stretch. Resume walking, and gradually increase the pace. Or if you plan on running, you could start out by walking and then stretching. Then try a brisk walk or any easy jog to take you into the aerobic phase.

Aerobic Phase

During the aerobic phase, you rev up, keep your body moving, and get your heart pumping. Your muscles will require more oxygen during this phase. Your heart beats faster and your lungs breathe deeper to deliver oxygen through your small blood vessels to muscles.

If you are starting a new exercise program, you may not be able to sustain aerobic activity for very long. That’s okay. Try 5–10 minutes at first, and gradually increase the aerobic phase. An easy workout is better than none at all. Sometimes once you get going, you will feel better and will go the whole way. Eventually, you will be able to go the full 20–30 minutes. Just listen to your body and slow down when you need to.


Pace Yourself

Remember to pace yourself. Listen to what your body is telling you. The key to a safe and effective workout is to find the pace that is right for you.


When to Stop or Slow Down Exercise

• If you start an aerobic workout and feel increasingly worse, slow down.

• If you think you are having a hypoglycemic episode, stop and check your blood glucose.

• If it’s not possible to check your blood glucose, treat your symptoms and check your blood glucose as soon as you can.

During aerobic exercise, you should be at your target heart rate. Your health care provider or exercise physiologist can advise you on the target zone that is safe for you. An exercise stress test can help determine your target heart rate. You can also calculate your target heart rate based on your age using the chart below.

How to Calculate Your Target Heart Rate

• Resting Heart Rate. Measure your heart rate while at rest by counting the number of beats your heart makes in 1 full minute the first thing in the morning before you get out of bed. Begin counting the first beat as zero.

• Maximum Heart Rate. Determine your maximum heart rate by subtracting your age from 220.

• Maximum Heart Rate Reserve. Subtract your resting heart rate from your maximum heart rate.

• Lower Limit of Heart Rate. Multiply your maximum heart rate reserve by 0.5 to determine 50% of your heart rate reserve. Add this number to your resting heart rate.

• Upper Limit of Heart Rate. Multiply your maximum heart rate reserve by 0.7 to determine 70% of your heart rate reserve. Add this number to your resting heart rate.

• Voilà. Your target heart rate range is between your lower and upper limit of your heart rate. Keep in mind that this calculation does not take into account any of your specific health conditions or medications. Check that your health care provider agrees with your calculated target heart rate.

Here’s an example of how it works. If you are 40 years old, your maximum heart rate is 180 (220 – 40 = 180). If your resting heart rate is 75, then you would have a heart rate target range of 128–149 (see below), to be working at 50–70% of your aerobic capacity.

p154.jpg

Be careful! This calculation does not take into account any of your specific health conditions or medications. Check that your provider agrees that the target heart rate you’ve calculated is safe for you.

Cool Down

A cool down allows your heart rate and breathing to slow gradually as your movement slows. No matter how tired you are, never stop exercising abruptly. This will help prevent soreness and muscle cramps.

• Keep your legs and arms moving at a relaxed pace.

• Walk around, step from side to side, walk in place, or try some easy kicks for 5–10 minutes.

• Avoid bending over so far that your head is below your heart.

• Afterward, stretch out your muscles again while they are warm. You should be able to stretch much more freely than in the warmup.

Types of Physical Activity and Exercise

You’ve probably heard “no pain, no gain” as a mantra of exercise. However, unless you’re Rocky Balboa, you can probably find some type of activity that is beneficial and fun. The key is to pick an activity that you enjoy and do it at a pace that is comfortable for you. You’ll be more likely to stick with your exercise plan if you take this approach.

There is no single perfect activity. There are some types that burn more calories, some that are particularly helpful for developing strength and flexibility, and others that are especially beneficial for your cardiovascular system.

Walking

Walking is probably the safest and least expensive form of physical activity. It can fit into almost anyone’s schedule because it can be integrated into other events. For example, you can squeeze in a walk instead of driving half a mile to the post office. The only investment you need to make is in a comfortable pair of walking shoes. In exchange for this—and extra attention to foot care—you get an exercise that conditions the cardiovascular system, lungs, arms, legs, abdomen, lower back, and buttocks.


Pedometer

A pedometer is an inexpensive tool that counts your steps and may measure the distance and duration of your walk. You might want to purchase one as a motivating and fun way to get moving more.

  About 2,000 steps are equal to a mile. Start by wearing your pedometer for two or three days to see how many steps you take with your current level of activity. Then gradually work to increase that to 10,000 steps a day.


Start Walking

• You can benefit your heart and lungs by walking 30 minutes per day, five times a week.

• You don’t have to walk 30 minutes all at once. You can get the same benefit by walking 10 minutes three times a day. For example, you might want to park farther from work, so you have a 10-minute walk in the morning and afternoon. You can then add a 10-minute walk at lunchtime, and you have completed your 30 minutes of exercise.

• If you are trying to lose weight, you will need to gradually increase the length of time to 60 minutes of walking per day.

Walking can be especially invigorating if you move at a brisk pace and travel over hilly terrain. Walking is a lifelong activity, and it is a good way to have a more active lifestyle. It can also help you ease into more vigorous exercise if you are newly diagnosed with diabetes or are not used to exercising.

For example, maybe you are a little afraid that exercising too vigorously will throw your blood glucose levels out of whack. After walking for a while, you will develop the confidence, stamina, and fitness level to try other activities.

Walk at a pace that is both enjoyable and invigorating for you. Some find that walking with hand weights makes for a more challenging workout, but before you do that check with your provider or exercise physiologist.


Walking Pace

An experienced walker can walk a mile in 10–12 minutes. A pace of 4 miles per hour or 15 minutes per mile is a good goal to work toward. However, in the beginning, it may take you 30 minutes to walk a mile.


Jogging and Running

Jogging or running will give you a more intense workout in less time than walking. But jogging is tougher on your joints and feet because each step pounds the foot with three to five times your body weight. Make sure that you discuss your running or jogging program with your provider before you start. Also, invest in a good pair of running shoes.


Good Shoes

• Try on shoes in the afternoon, when foot size tends to be a little bigger.

• Wear the socks you plan to wear while working out. You may want to try special socks designed with extra cushioning for exercise. In truth, any good athletic sock that is made with a blend of cotton and synthetic material will provide warmth and cushioning and wick perspiration away.

• Choose shoes that fit well and are comfortable from the first time you put them on. If you have nerve disease or decreased feeling in your feet, you may not be able to trust the way a shoe feels when you try it on. Consult a podiatrist or professional shoe fitter (pedorthist) to get a correct fit.

• Wear new shoes for short periods at first.

• Check your feet for red, irritated areas. You may need extra padding in some areas of the shoe to prevent friction.


Avoid jogging on concrete—it’s too hard. Try the track at a nearby school or park instead. Take time to develop your leg and foot muscles to reduce the possibility of injury. If you start to develop any persistent pain, especially in your joints, don’t risk further injury. Rest, take a few days off, or try walking instead.

Progressing from Walking to Running

• Start walking your normal route or distance.

• Walk for a few minutes and then try jogging.

• Jog for as long as you feel comfortable. If you start to feel winded or uncomfortably out of breath, switch to a brisk walk. Don’t stop, but keep walking.

• When you have regained your breath, jog for a little bit. You may find that eventually you will be able to jog the whole distance.

• Of course, you may want to stick to a combination of running and walking or you may want to alternate some days running and some days walking. Do what feels good to you.

Strength Training

Almost anyone can benefit from strength training. Well-toned muscles can help in all your daily activities, whether it’s carrying groceries, climbing stairs, or doing laundry. Strength training can also help prevent osteoporosis and build muscle, especially in elderly people. As people get older, they tend to lose muscle mass and tone. Lifting weights—even into your 80s and 90s—can improve strength.

Another benefit of weight training is that well-toned and larger muscles burn more calories, even when you’re doing absolutely nothing. So a regular weightlifting program can help you lose fat and manage blood glucose levels in the long run, both during and between workouts.

Safe Strength Training

• Talk to your health care provider before starting any weightlifting routine. Ask them about how the routine might affect any diabetes complications or your blood pressure.

• Always do 5–10 minutes of some sort of aerobic activity, such as walking, jogging, or jumping rope, before lifting weights.

• Don’t hold your breath while lifting. Instead, breathe in when lowering weights and breathe out when lifting.

• Work out with a partner or trainer who can help you if something goes wrong.

• Cool down after lifting weights.

• Always allow at least a day’s rest between workout sessions or alternate between upper-body training one day and lower-body training the next.

There are several approaches to weight training. Most people combine weight training with aerobic activity for a complete workout. It can be as simple as lifting a small set of hand weights in your living room. Or you may want to join a gym or health club where you will have access to a whole array of weight machines and fitness equipment.

Most weight-training programs involve sets of weightlifting exercises. Each set consists of a series of repetitions. When you first start, perform one set each session. Eventually work your way up to three to six sets each session. As you become stronger you will also find that you can lift more weight. Add more weight, a little at a time, as your muscles become stronger.

Strength Training Goals

• If you just want to increase your endurance, choose a weight that you can lift only 15–20 times. Rest for a few minutes between each set of repetitions, also called reps.

• If you want to build both strength and endurance, choose a weight you can lift only 8–12 times. Rest for a few minutes between sets of reps.

• If you are geared toward competitive weightlifting, you might want to maximize your strength by choosing a weight you can lift only 2–6 times. Rest a few minutes between sets of reps.

Other Types of Physical Activity

Try yoga to increase your flexibility or aerobic classes if you like to dance. Community and senior centers may have equipment available or offer classes that are free or reasonably priced. Health clubs may offer free trial memberships so you can try out machines to see if there are any you would use at home.

You could rekindle your love of tennis, squash, or volleyball. Make an aerobic challenge out of washing the windows or sweeping the deck.

Your choice of activity might also take into account other factors, such as the weather. For example, if it is too hot or cold outside, consider walking inside at a local mall or around your house.

Special Precautions for Physical Activity and Exercise

You’ll want to take special care of your feet when you work out, especially if you’ve had diabetes for a while. Most children and teens with diabetes don’t need to think too much about foot complications. Check your feet daily for any red, irritated areas, blisters, corns, calluses, or ingrown toenails. If you detect a problem, don’t expect it will go away on its own. Call your diabetes provider or podiatrist right away.

Certain diabetes complications might affect your choice of activity, so always discuss safe options with your doctor.

Exercising with Diabetes Complications

• Nerve disease (peripheral neuropathy) and numb feet. You may need to limit weight-bearing activities, such as jogging. Riding a stationary bike or walking may be a safe alternative, but you will need to take extra care to protect your feet.

• Nerve disease (autonomic neuropathy). Avoid certain aerobic activities that might affect your heart rate and blood pressure control.

• Eye disease (proliferative retinopathy). You could threaten your vision with certain motions involved in weightlifting. Ask your health care provider.

• High blood pressure or heart disease. Avoid activities that involve pushing against an immovable object, such as a wall, or isometric exercises, in which you keep your muscles contracted. Walking and swimming are often safe options.

• Dialysis. You can benefit from a gradually progressing activity program.

• Organ transplantation. Physical activity can be helpful for people who have had an organ transplant. Anti-rejection drugs often cause weight gain and muscle wasting. Try aerobic and strength training once you are given the okay and are ready.

Physical Activity and Your Blood Glucose

Regular physical activity is a great tool for lowering blood glucose levels. Your body uses glucose stored in your muscles and liver for fuel when you start exercising. Then, as these stores diminish, your muscles recruit glucose from your blood. So, during exercise, your blood glucose levels can fall.

If you have type 1 diabetes or you have type 2 diabetes and take insulin and a sulfonylurea, you don’t want your blood glucose to get too low. Physical activity puts you at risk for hypoglycemia. Your blood glucose levels can also fall after exercise, as your body replenishes the stores of glucose in your muscles and liver. Even hours after you’ve stopped exercising, you need to be on the lookout for low blood glucose. Exercise-induced low blood glucose is mostly a problem for people who take insulin or some other diabetes medications.

Monitoring Blood Glucose during Physical Activity and Exercise

• Check your blood glucose level before you work out. If your blood glucose is less than 100 mg/dl, have a snack, such as a piece of fruit or a few crackers.

• Then test 15–30 minutes later. Don’t start exercising until your blood glucose is above 100 mg/dl.

Physical activity can also affect the action of insulin. The body absorbs insulin differently from one day to the next. Similarly, exercise can affect insulin absorption. Physical activity speeds up how fast the insulin you inject goes to work by increasing the flow of blood through your body. For example, injecting into an arm or leg involved in exercise can speed up insulin absorption. Given insulin’s varying effects, make sure to check your blood glucose levels whenever you exercise.


Overnight Lows after Exercise

If you exercise in the evening, you may leave yourself vulnerable to hypoglycemia while you sleep. Make sure to check your blood glucose before you go to bed and perhaps overnight.


Physical Activity and Type 1 Diabetes

The way that physical activity affects blood glucose levels in people with type 1 diabetes is a bit complicated. People with type 1 diabetes need to take extra care that blood glucose levels do not swing too widely. This includes knowing how your blood glucose responds to different types of activities. You can learn this by monitoring often—before, during, and after working out.

Lows during Exercise

• Blood glucose levels can swing too low if you exercise for long periods or on an empty stomach.

• You’ll want to make sure you have taken the right amount of insulin to get the most benefit from your workout. Take the time to learn how to predict your insulin and food needs by monitoring in all types of situations.

• If you suspect a low blood glucose reaction coming on, stop exercising at once. Eat or drink some type of carbohydrate. Don’t fool yourself into thinking you can last just 5 minutes longer.

• Always keep some form of glucose handy, just in case you need it while exercising. This can be a soft drink or fruit juice, which will provide sugar and replace water. Or you can use glucose tablets, raisins, or hard candy.

• Blood glucose can drop to lower levels up to 16–24 hours after exercise because the body uses glucose from the blood to replenish muscles. So make sure to monitor your blood glucose before, after, and long after exercise.

Highs during Exercise

• Blood glucose levels can also swing too high if you exercise vigorously or if your body does not have enough available insulin.

• Sometimes during vigorous exercise, the nerves signal the liver to release stored glucose, which can cause a rapid rise in blood glucose. This rise occurs even with moderate intensity if your insulin levels are too low.

• A high blood glucose level can go even higher because of exercise.

• Your body might produce ketones, and ketoacidosis can result. Check your blood glucose before and after exercising to avoid high blood glucose.

You may need to eat during or after exercising if you work out hard or for a long time. Try snacking on something that is low in fat and has 15–30 grams of carbohydrate. If you are really going at it, you may need to repeat this snack based on blood glucose levels.

Before you start exercising you may need to know which way your blood glucose level is heading. This especially true if you are about to start an activity in which you cannot easily stop (such as a long run or windsurfing). Checking your blood glucose in the middle of your activity may not be convenient or possible. Try checking 90 minutes before you start. If your monitoring shows that your blood glucose level is coming down (even if you are still in a safe range), you may want to have a snack to keep it from going any lower.

Insulin and Exercise

You’ll read more about insulin in chapter 13, but here are a few things to keep in mind.

• If you have a fixed regimen of insulin taken at specific times of day, try to schedule exercise at about the same time every day.

• If you have a more flexible insulin plan, discuss with your health care provider how to adjust insulin based on your physical activity.

• Avoid exercising when your insulin is peaking, which is usually within 1–2 hours of your last injection of rapid-acting or regular insulin.

• Consider where you inject insulin in your body. Muscles involved in exercise absorb insulin more readily.

Physical Activity and Type 2 Diabetes

Regular physical activity is an important part of the management plan for people with type 2 diabetes. Many people with type 2 diabetes find their blood glucose levels are much easier to manage if they exercise regularly (because their bodies become less resistant to insulin).

Ask your doctor about any diabetes complications before you start an exercise program. However, be assured that almost everyone can benefit from some form of physical activity, as long as it doesn’t increase your risk of injury.

Review your meal and exercise plan with your health care team to be sure you are getting enough vitamins and minerals and you are replacing the fluids lost during exercise. If you are on a very-low-calorie diet (fewer than 800 calories a day), your provider may closely monitor your exercise and overall health.

If you use insulin, you’ll need to take steps to prevent low blood glucose. See the previous section: “Physical Activity and Type 1 Diabetes.” If you take certain diabetes medications, such as exenatide, a sulfonylurea, or meglitinide, hypoglycemia is rare, but it can still occur, so know what to look for and how to treat it. People with type 2 diabetes who manage their diabetes with meal planning and exercise but without medication almost never have hypoglycemia.

Physical Activity and Pregnancy

Pregnancy is no reason to stop working out if you have type 1 or type 2 diabetes and exercise regularly. However, you may need to lower your workout intensity. You’ll need to consult your doctors about the type of workout you want to do. They will consider your medical history and advise you about whether it is safe.


Start Slow

Don’t start a new strenuous exercise program when you’re pregnant, especially if you didn’t exercise regularly before pregnancy. Instead, you may be able to start a new program of low-intensity activities such as walking or swimming.


Physical Activity and Gestational Diabetes

• Physical activity lowers your blood glucose level and is considered part of your treatment plan.

• Staying physically fit during your pregnancy will help you prepare for the work of labor and baby care that lies ahead.

• Working out can moderate your weight gain, increase your strength and stamina, and lower your anxiety level.

• In some cases, it may help you avoid or delay using insulin.

Most women use intensive diabetes management during pregnancy to keep blood glucose levels close to normal. If that is your goal, you’ll need to be extra watchful for low blood glucose levels caused by exercise. Your glucose level can go very low very quickly. Monitoring is your way to watch out for hypoglycemia. Chances are that you’ll already be monitoring frequently during pregnancy. This can help you figure out how exercise affects your blood glucose and when your levels are starting to drop.

Safe Exercise during Pregnancy

• Monitor your blood glucose levels often—before, during, and after exercise.

• Drink plenty of fluids before, during, and after exercise.

• Warm up before and cool down after exercise.

• Keep the strenuous part of your workout to no longer than 15 minutes.

• Keep your heart rate under 140 beats per minute while you exercise (about 23 beats per 10-second pulse count).

• Keep your body temperature under 100°F. Ask your provider if hot tubs or steam rooms are safe.

• Avoid exercises that involve lying on your back after your fourth month of pregnancy, straining or holding your breath, jerky movements, or quick changes in direction.

• Stop exercising if you feel lightheaded, weak, or very out of breath.

• Ask your obstetrician to show you how to feel your uterus for contractions during exercise. These contractions could be a sign you’re overdoing it.

Get Out There

Now that you’ve learned about the benefits of physical activity and exercise, it’s time to get out there and get started. Keep in mind that change doesn’t happen overnight. It will take several months for your new, more active lifestyle to become a habit. To keep on track, consider scheduling your workouts like you would any other appointments. You may want to find a workout partner who will keep you motivated when you are tempted to skip a workout.

Set realistic goals including long-term goals, such as walking 30 minutes a day 5 days a week, and short-term goals, such as “I’m going try strength-training today.” You may want to do a variety of exercises to keep your interest piqued in working out. Track your progress by recording noticeable changes, such as your energy level, weight, belt size, and changes in medications.


Reward Yourself

Sticking to a physical activity program is hard work. Remember to reward yourself for all your efforts. Do an easier workout, such as yoga, one day a week. Don’t skip the hot tub or steam room if you really enjoy them after your workout (just ask your doctor if they are safe if you have high blood pressure or are pregnant).



If you find an error or have any questions, please email us at admin@doctorlib.info. Thank you!