Physical Activity and Weight Control: NIDDK

Article title: Physical Activity and Weight Control: NIDDK
Conditions: overweight, obesity, stroke, heart disease, high blood pressure, back pain, osteoporosis
Source: NIDDK

How Can Physical Activity Help Control My Weight?
What Are the Health Benefits of Physical Activity?
How Much Should I Exercise?
Moderate-Intensity Activity
Aerobic Activity
Stretching and Muscle Strengthening Exercises
Tips to a Safe and Successful Physical Activity Program
Additional Resources

Regular physical activity is an important part of effective weight loss and weight maintenance. It also can help prevent several diseases and improve your overall health. It does not matter what type of physical activity you perform--sports, planned exercise, household chores, yard work, or work-related tasks--all are beneficial. Studies show that even the most inactive people can gain significant health benefits if they accumulate 30 minutes or more of physical activity per day. Based on these findings, the U.S. Public Health Service has identified increased physical activity as a priority in Healthy People 2000, our national objectives to improve the health of Americans by the year 2000.

Research consistently shows that regular physical activity, combined with healthy eating habits, is the most efficient and healthful way to control your weight. Whether you are trying to lose weight or maintain it, you should understand the important role of physical activity and include it in your lifestyle.

How Can Physical Activity Help Control My Weight?

Physical activity helps to control your weight by using excess calories that otherwise would be stored as fat. Your body weight is regulated by the number of calories you eat and use each day. Everything you eat contains calories, and everything you do uses calories, including sleeping, breathing, and digesting food. Any physical activity in addition to what you normally do will use extra calories.

Balancing the calories you use through physical activity with the calories you eat will help you achieve your desired weight. When you eat more calories than you need to perform your day's activities, your body stores the extra calories and you gain weight (a).

When you eat fewer calories than you use, your body uses the stored calories and you lose weight (b). When you eat the same amount of calories as your body uses, your weight stays the same (c).

Any type of physical activity you choose to do--strenuous activities such as running or aerobic dancing or moderate-intensity activities such as walking or household work--will increase the number of calories your body uses. The key to successful weight control and improved overall health is making physical activity a part of your daily routine.

What Are the Health Benefits of Physical Activity?

In addition to helping to control your weight, research shows that regular physical activity can reduce your risk for several diseases and conditions and improve your overall quality of life. Regular physical activity can help protect you from the following health problems.

Heart Disease and Stroke. Daily physical activity can help prevent heart disease and stroke by strengthening your heart muscle, lowering your blood pressure, raising your high-density lipoprotein (HDL) levels (good cholesterol) and lowering low-density lipoprotein (LDL) levels (bad cholesterol), improving blood flow, and increasing your heart's working capacity.
High Blood Pressure. Regular physical activity can reduce blood pressure in those with high blood pressure levels. Physical activity also reduces body fatness, which is associated with high blood pressure.
Noninsulin-Dependent Diabetes. By reducing body fatness, physical activity can help to prevent and control this type of diabetes.
Obesity. Physical activity helps to reduce body fat by building or preserving muscle mass and improving the body's ability to use calories. When physical activity is combined with proper nutrition, it can help control weight and prevent obesity, a major risk factor for many diseases.
Back Pain. By increasing muscle strength and endurance and improving flexibility and posture, regular exercise helps to prevent back pain.
Osteoporosis. Regular weight-bearing exercise promotes bone formation and may prevent many forms of bone loss associated with aging.

Studies on the psychological effects of exercise have found that regular physical activity can improve your mood and the way you feel about yourself. Researchers also have found that exercise is likely to reduce depression and anxiety and help you to better manage stress.

Keep these health benefits in mind when deciding whether or not to exercise. And remember, any amount of physical activity you do is better than none at all.

How Much Should I Exercise?

For the greatest overall health benefits, experts recommend that you do 20 to 30 minutes of aerobic activity three or more times a week and some type of muscle strengthening activity and stretching at least twice a week. However, if you are unable to do this level of activity, you can gain substantial health benefits by accumulating 30 minutes or more of moderate-intensity physical activity a day, at least five times a week.

If you have been inactive for a while, you may want to start with less strenuous activities such as walking or swimming at a comfortable pace. Beginning at a slow pace will allow you to become physically fit without straining your body. Once you are in better shape, you can gradually do more strenuous activity.

Moderate-
Intensity
Activity

Moderate-intensity activities include some of the things you may already be doing during a day or week, such as gardening and housework. These activities can be done in short spurts--10 minutes here, 8 minutes there. Alone, each action does not have a great effect on your health, but regularly accumulating 30 minutes of activity over the course of the day can result in substantial health benefits.

To become more active throughout your day, take advantage of any chance to get up and move around. Here are some examples:

Take a short walk around the block
Rake leaves
Play actively with the kids
Walk up the stairs instead of taking the elevator
Mow the lawn
Take an activity break--get up and stretch or walk around
Park your car a little farther away from your destination and walk the extra distance

The point is not to make physical activity an unwelcome chore, but to make the most of the opportunities you have to be active.

Aerobic Activity

Aerobic activity is an important addition to moderate-intensity exercise. Aerobic exercise is any extended activity that makes you breathe hard while using the large muscle groups at a regular, even pace. Aerobic activities help make your heart stronger and more efficient. They also use more calories than other activities. Some examples of aerobic activities include:

Brisk walking
Jogging
Bicycling
Swimming
Aerobic dancing
Racket sports
Rowing
Ice or roller skating
Cross-country or downhill skiing
Using aerobic equipment (i.e., treadmill, stationary bike)

To get the most health benefits from aerobic activity, you should exercise at a level strenuous enough to raise your heart rate to your target zone. Your target heart rate zone is 50 to 75 percent of your maximum heart rate (the fastest your heart can beat). To find your target zone, look for the category closest to your age in the chart below and read across the line. For example, if you are 35 years old, your target heart rate zone is 93-138 beats per minute.

Age	Target Heart Rate Zone 50-75%	Average Maximum Heart Rate 100%
20-30 years	98-146 beats per min.	195
31-40 years	93-138 beats per min.	185
41-50 years	88-131 beats per min.	175
51-60 years	83-123 beats per min.	165
61+ years	78-116 beats per min	155

To see if you are exercising within your target heart rate zone, count the number of pulse beats at your wrist or neck for 15 seconds, then multiply by four to get the beats per minute. Your heart should be beating within your target heart rate zone. If your heart is beating faster than your target heart rate, you are exercising too hard and should slow down. If your heart is beating slower than your target heart rate, you should exercise a little harder.

When you begin your exercise program, aim for the lower part of your target zone (50 percent). As you get into better shape, slowly build up to the higher part of your target zone (75 percent). If exercising within your target zone seems too hard, exercise at a pace that is comfortable for you. You will find that, with time, you will feel more comfortable exercising and can slowly increase to your target zone.

Stretching and Muscle Strengthening Exercises

Stretching and strengthening exercises such as weight training should also be a part of your physical activity program. In addition to using calories, these exercises strengthen your muscles and bones and help prevent injury.

Tips to a Safe and Successful Physical Activity Program

Make sure you are in good health. Answer the following questions* before you begin exercising.

Has a doctor ever said you have heart problems?
Do you frequently suffer from chest pains?
Do you often feel faint or have dizzy spells?
Has a doctor ever said you have high blood pressure?
Has a doctor ever told you that you have a bone or joint problem, such as arthritis, that has been or could be aggravated by exercise?
Are you over the age of 65 and not accustomed to exercise?
Are you taking prescription medications, such as those for high blood pressure?
Is there a good medical reason, not mentioned here, why you should not exercise?

*Source: British Columbia Department of Health

If you answered "yes" to any of these questions, you should see your doctor before you begin an exercise program.

Follow a gradual approach to exercise to get the most benefits with the fewest risks. If you have not been exercising, start at a slow pace and as you become more fit, gradually increase the amount of time and the pace of your activity.
Choose activities that you enjoy and that fit your personality. For example, if you like team sports or group activities, choose things such as soccer or aerobics. If you prefer individual activities, choose things such as swimming or walking. Also, plan your activities for a time of day that suits your personality. If you are a morning person, exercise before you begin the rest of your day's activities. If you have more energy in the evening, plan activities that can be done at the end of the day. You will be more likely to stick to a physical activity program if it is convenient and enjoyable.
Exercise regularly. To gain the most health benefits it is important to exercise as regularly as possible. Make sure you choose activities that will fit into your schedule.
Exercise at a comfortable pace. For example, while jogging or walking briskly you should be able to hold a conversation. If you do not feel normal again within 10 minutes following exercise, you are exercising too hard. Also, if you have difficulty breathing or feel faint or weak during or after exercise, you are exercising too hard.
Maximize your safety and comfort. Wear shoes that fit and clothes that move with you, and always exercise in a safe location. Many people walk in indoor shopping malls for exercise. Malls are climate controlled and offer protection from bad weather.
Vary your activities. Choose a variety of activities so you don't get bored with any one thing.
Encourage your family or friends to support you and join you in your activity. If you have children, it is best to build healthy habits when they are young. When parents are active, children are more likely to be active and stay active for the rest of their lives.
Challenge yourself. Set short-term as well as long-term goals and celebrate every success, no matter how small.
Whether your goal is to control your weight or just to feel healthier, becoming physically active is a step in the right direction. Take advantage of the health benefits that regular exercise can offer and make physical activity a part of your lifestyle.

Additional Resources

The following organizations have materials on physical activity and weight control available to the public.

President's Council on Physical Fitness and Sports
701 Pennsylvania Avenue, NW
Suite 250
Washington, DC 20004
Tel: (202) 272-3421

National Heart, Lung, and Blood Institute
Information Center
P.O. Box 30105
Bethesda, MD 20824-0105
Tel: (301) 251-1222

American College of Sports Medicine
P.O. Box 1440
Indianapolis, IN 46206-1440
Tel: (317) 637-9200

Weight-control Information Network

1 Win Way
Bethesda, MD 20892-3665
Tel: (202) 828-1025 or 1-877-946-4627
Fax: (202) 828-1028
E-mail: win@info.niddk.nih.gov

The Weight-control Information Network (WIN) is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health, under the U.S. Public Health Service. Authorized by Congress (Public Law 103-43), WIN assembles and disseminates to health professionals and the public information on weight control, obesity, and nutritional disorders. WIN responds to requests for information; develops, reviews, and distributes publications; and develops communications strategies to encourage individuals to achieve and maintain a healthy weight.

Publications produced by the clearinghouse are reviewed carefully for scientific accuracy, content, and readability.

This e-text is not copyrighted. The clearinghouse encourages users of this e-pub to duplicate and distribute as many copies as desired.

NIH Publication No. 96-4031
April 1996

e-text posted: 20 February 1998

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