| |
Physical
Activity and Weight Control
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.
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.
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
Phone: (202) 272-3421
National Heart, Lung, and Blood
Institute
Information Center
P.O. Box 30105
Bethesda, MD 20824-0105
Phone: (301) 251-1222
American College of Sports Medicine
P.O. Box 1440
Indianapolis, IN 46206-1440
Phone: (317) 637-9200
Weight-control Information
Network
1 Win Way
Bethesda, MD 20892-3665
Phone: (301) 984-7378 or 1-800-WIN-8098
Fax: (301) 984-7196
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). Path:
Home>Education>Fitness
and Physical Activity Information>Physical
Activity and Weight Control
|
|