Exercise and Weight Control
Just about everybody seems to be interested
in weight control. Some of us weigh just the right amount,
others need to gain a few pounds. Most of us "battle
the bulge" at some time in our life. Whatever our
goals, we should understand and take advantage of the
important role of exercise in keeping our weight under
control.
Carrying around too much body fat is a major nuisance.
Yet excess body fat is common in modern-day living.
Few of today's occupations require vigorous physical
activity, and much of our leisure time is spent in sedentary
pursuits.
Recent estimates indicate that 34
million adults are considered obese (20 percent above
desirable weight). Also, there has been an increase
in body fat levels in children and youth over the past
20 years. After infancy and early childhood, the earlier
the onset of obesity, the greater the likelihood of
remaining obese.
Excess body fat has been linked to
such health problems as coronary heart disease, high
blood pressure, osteoporosis, diabetes, arthritis and
certain forms of cancer. Some evidence now exists showing
that obesity has a negative effect on both health and
longevity.
Exercise is associated with the loss
of body fat in both obese and normal weight persons.
A regular program of exercise is an important component
of any plan to help individuals lose, gain or maintain
their weight.
Overweight or Overfat?
Overweight and overfat do not always
mean the same thing. Some people are quite muscular
and weigh more than the average for their age and height.
However, their body composition, the amount of fat versus
lean body mass (muscle, bone, organs and tissue), is
within a desirable range. This is true for many athletes.
Others weigh an average amount yet carry around too
much fat. In our society, however, overweight often
implies overfat because excess weight is commonly distributed
as excess fat. The addition of exercise to a weight
control program helps control both body weight and body
fat levels.
A certain amount of body fat is necessary
for everyone. Experts say that percent body fat for
women should be about 20 percent, 15 percent for men.
Women with more than 30 percent fat and men with more
than 25 percent fat are considered obese.
How much of your weight is fat can
be assessed by a variety of methods including underwater
(hydrostatic) weighing, skinfold thickness measurements
and circumference measurements. Each requires a specially
trained person to administer the test and perform the
correct calculations. From the numbers obtained, a body
fat percentage is determined. Assessing body composition
has an advantage over the standard height-weight tables
because it can help distinguish between "overweight"
and "overfat."
An easy self-test you can do is to
pinch the thickness of the fat folds at your waist and
abdomen. If you can pinch an inch or more of fat (make
sure no muscle is included) chances are you have too
much body fat.
People who exercise appropriately
increase lean body mass while decreasing their overall
fat level. Depending on the amount of fat loss, this
can result in a loss of inches without a loss of weight,
since muscle weighs more than fat. However, with the
proper combination of diet and exercise, both body fat
and overall weight can be reduced.
Energy Balance: A Weighty Concept
Losing weight, gaining weight or maintaining
your weight depends on the amount of calories you take
in and use up during the day, otherwise referred to
as energy balance. Learning how to balance energy intake
(calories in food) with energy output (calories expended
through physical activity) will help you achieve your
desired weight.
Although the underlying causes and
the treatments of obesity are complex, the concept of
energy balance is relatively simple. If you eat more
calories than your body needs to perform your day's
activities, the extra calories are stored as fat. If
you do not take in enough calories to meet your body's
energy needs, your body will go to the stored fat to
make up the difference. (Exercise helps ensure that
stored fat, rather than muscle tissue, is used to meet
your energy needs.) If you eat just about the same amount
of calories to meet your body's energy needs, your weight
will stay the same.
On the average, a person consumes
between 800,000 and 900,000 calories each year! An active
person needs more calories than a sedentary person,
as physically active people require energy above and
beyond the day's basic needs. All too often, people
who want to lose weight concentrate on counting calorie
intake while neglecting calorie output. The most powerful
formula is the combination of dietary modification with
exercise. By increasing your daily physical activity
and decreasing your caloric input you can lose excess
weight in the most efficient and healthful way.
Counting Calories
Each pound of fat your body stores
represents 3,500 calories of unused energy. In order
to lose one pound, you would have to create a calorie
deficit of 3,500 calories by either taking in 3,500
less calories over a period of time than you need or
doing 3,500 calories worth of exercise. It is recommended
that no more than two pounds (7,000 calories) be lost
per week for lasting weight loss.
Adding 15 minutes of moderate exercise,
say walking one mile, to your daily schedule will use
up 100 extra calories per day. (Your body uses approximately
100 calories of energy to walk one mile, depending on
your body weight.) Maintaining this schedule would result
in an extra 700 calories per week used up, or a loss
of about 10 pounds in one year, assuming your food intake
stays the same. To look at energy balance another way,
just one extra slice of bread or one extra soft drink
a day or any other food that contains approximately
100 calories can add up to ten extra pounds in
a year if the amount of physical activity you do does
not increase.
lf you already have a lean figure
and want to keep it you should exercise regularly and
eat a balanced diet that provides enough calories to
make up for the energy you expend. If you wish to gain
weight you should exercise regularly and increase the
number of calories you consume until you reach your
desired weight. Exercise will help ensure that the weight
you gain will be lean muscle mass, not extra fat.
The Diet Connection
A balanced diet should be part of
any weight control plan. A diet high in complex carbohydrates
and moderate in protein and fat will complement an exercise
program. It should include enough calories to satisfy
your daily nutrient requirements and include the proper
number of servings per day from the "basic four
food groups": vegetables and fruits (4 servings),
breads and cereals (4 servings), milk and milk products
(2 - 4 depending on age) and meats and fish (2).
Experts recommend that your daily
intake not fall below 1200 calories unless you are under
a doctor's supervision. Also, weekly weight loss should
not exceed two pounds.
Remarkable claims have been made for
a variety of "crash" diets and diet pills.
And some of these very restricted diets do result in
noticeable weight loss in a short time. Much of this
loss is water and such a loss is quickly regained when
normal food and liquid intake is resumed. These diet
plans are often expensive and may be dangerous. Moreover,
they do not emphasize lifestyle changes that will help
you maintain your desired weight. Dieting alone will
result in a loss of valuable body tissue such as muscle
mass in addition to a loss in fat.
How Many Calories
The estimates for number of calories
(energy) used during a physical activity are based on
experiments that measure the amount of oxygen consumed
during a specific bout of exercise for a certain body
weight.
The energy costs of activities that
require you to move your own body weight, such as walking
or jogging, are greater for heavier people since they
have more weight to move. For example, a person weighing
150 pounds would use more calories jogging one mile
than a person jogging alongside who weighs 115 pounds.
Always check to see what body weight is referred to
in caloric expenditure charts you use.
Energy Expenditure Chart
A.
Sedentary Activities |
Energy
Costs
Cals/Hour* |
Lying
down or sleeping |
|
90 |
Sitting
quietly |
|
84 |
Sitting
and writing, card
playing, etc. |
|
114 |
B.
Moderate Activities |
(150-350) |
Bicycling
(5 mph) |
|
174 |
Canoeing
(2.5 mph) |
|
174 |
Dancing
(Ballroom) |
|
210 |
Golf
(2-some, carrying clubs) |
|
324 |
Horseback
riding (sitting to trot) |
|
246 |
Light
housework, cleaning, etc. |
|
246 |
Swimming
(crawl, 20 yards/min) |
|
288 |
Tennis
(recreational doubles) |
|
312 |
Volleyball
(recreational) |
|
264 |
Walking
(2 mph) |
|
198 |
C.
Vigorous Activities |
More
than 350 |
Aerobic
Dancing |
|
546 |
Basketball
(recreational) |
|
450 |
Bicycling
(13 mph) |
|
612 |
Circuit
weight training |
|
756 |
Football
(touch, vigorous) |
|
498 |
Ice
Skating (9 mph) |
|
384 |
Racquetball
|
|
588 |
Roller
Skating (9 mph) |
|
384 |
Jogging
(10 minute mile, 6 mph) |
|
654 |
Scrubbing
Floors |
|
440 |
Swimming
(crawl, 45 yards/min) |
|
522 |
Tennis
(recreational singles) |
|
450 |
X-country
Skiing ( 5 mph) |
|
690 |
*Hourly estimates based on values
calculated for calories burned per minute for a 150
pound (68 kg) person.
*(Sources: "William D. McArdle,
Frank I. Katch, Victor L. Katch, "Exercise Physiology:
Energy, Nutrition and Human Performance" (2nd edition),
Lea & Febiger, Philadelphia, 1986; Melvin H. Williams,
"Nutrition for Fitness and Sport," William
C. Brown Company Publishers, Dubuque, 1983.)
Exercise and Modern Living
One thing is certain. Most people
do not get enough exercise in their ordinary routines.
All of the advances of modern technology from
electric can openers to power steering have made
life easier, more comfortable and much less physically
demanding. Yet our bodies need activity, especially
if they are carrying around too much fat. Satisfying
this need requires a definite plan, and a commitment.
There are two main ways to increase the number of calories
you expend:
- Start a regular exercise program
if you do not have one already.
- Increase the amount of physical
activity in your daily routine.
The best way to control your weight
is a combination of the above. The sum total of calories
used over time will help regulate your weight as well
as keep you physically fit.
Active Lifestyles
Before looking at what kind of regular
exercise program is best, let's look at how you can
increase the amount of physical activity in your daily
routine to supplement your exercise program.
- Recreational pursuits such as gardening
on weekends, bowling in the office league, family
outings, an evening of social dancing, and many other
activities provide added exercise. They are fun and
can be considered an extra bonus in your weight control
campaign.
- Add more "action" to
your day. Walk to the neighborhood grocery store instead
of using the car. Park several blocks from the office
and walk the rest of the way. Walk up the stairs instead
of using the elevator; start with one flight of steps
and gradually increase.
- Change your attitude toward movement.
Instead of considering an extra little walk or trip
to the files an annoyance, look upon it as an added
fitness boost. Look for opportunities to use your
body. Bend, stretch, reach, move, lift and carry.
Time-saving devices and gadgets eliminate drudgery
and are a bonus to mankind, but when they substitute
too often for physical activity they can demand a
high cost in health, vigor and fitness.
These little bits of action are cumulative
in their effects. Alone, each does not burn a huge amount
of calories. But when added together they can result
in a sizable amount of energy used over the course of
the day. And they will help improve your muscle tone
and flexibility at the same time.
What Kind of Exercise?
Although any kind of physical movement
requires energy (calories), the type of exercise that
uses the most energy is aerobic exercise. The term "aerobic"
is derived from the Greek word meaning "with oxygen."
Jogging, brisk walking, swimming, biking, cross-country
skiing and aerobic dancing are some popular forms of
aerobic exercise.
Aerobic exercises use the body's large
muscle groups in continuous, rhythmic, sustained movement
and require oxygen for the production of energy. When
oxygen is combined with food (which can come from stored
fat) energy is produced to power the body's musculature.
The longer you move aerobically, the more energy needed
and the more calories used. Regular aerobic exercise
will improve your cardiorespiratory endurance, the ability
of your heart, lungs, blood vessels and associated tissues
to use oxygen to produce energy needed for activity.
You'll build a healthier body while getting rid of excess
body fat.
In addition to the aerobic exercise,
supplement your program with muscle strengthening and
stretching exercises. The stronger your muscles, the
longer you will be able to keep going during aerobic
activity, and the less chance of injury.
How Much? How Often?
Experts recommend that you do some
form of aerobic exercise at least three times a week
for a minimum of 20 continuous minutes. Of course, if
that is too much, start with a shorter time span and
gradually build up to the minimum. Then gradually progress
until you are able to work aerobically for 20-40 minutes.
If you need to lose a large amount of weight, you may
want to do your aerobic workout five times a week.
It is important to exercise at an
intensity vigorous enough to cause your heart rate and
breathing to increase. How hard you should exercise
depends to a certain degree on your age, and is determined
by measuring your heart rate in beats per minute.
The heart rate you should maintain
is called your target heart rate, and there are several
ways you can arrive at this figure. The simplest is
to subtract your age from 220 and then calculate 60
to 80 percent of that figure. Beginners should maintain
the 60 percent level, more advanced can work up to the
80 percent level. This is just a guide however, and
people with any medical limitations should discuss this
formula with their physician.
You can do different types of aerobic
activities, say walking one day, riding a bike the next.
Make sure you choose an activity that can be done regularly,
and is enjoyable for you. The important thing to remember
is not to skip too many days between workouts or fitness
benefits will be lost. If you must lose a few days,
gradually work back into your routine.
The Benefits of Exercise in a Weight
Control Program
The benefits of exercise are many,
from producing physically fit bodies to providing an
outlet for fun and socialization. When added to a weight
control program these benefits take on increased significance.
We already have noted that proper
exercise can help control weight by burning excess body
fat. It also has two other body-trimming advantages
1) exercise builds muscle tissue and muscle uses calories
up at a faster rate than body fat; and 2) exercise helps
reduce inches and a firm, lean body looks slimmer even
if your weight remains the same.
Remember, fat does not "turn
into" muscle, as is often believed. Fat and muscle
are two entirely different substances and one cannot
become the other. However, muscle does use calories
at a faster rate than fat which directly affects your
body's metabolic rate or energy requirement. Your basal
metabolic rate (BMR) is the amount of energy required
to sustain the body's functions at rest and it depends
on your age, sex, body size, genes and body composition.
People with high levels of muscle tend to have higher
BMRs and use more calories in the resting stage.
Some studies have even shown that
your metabolic rate stays elevated for some time after
vigorous exercise, causing you to use even more calories
throughout your day. Additional benefits may be seen
in how exercise affects appetite. A lean person in good
shape may eat more following increased activity, but
the regular exercise will burn up the extra calories
consumed. On the other hand, vigorous exercise has been
reported to suppress appetite. And, physical activity
can be used as a positive substitute for between meal
snacking.
Better Mental Health
The psychological benefits of exercise
are equally important to the weight conscious person.
Exercise decreases stress and relieves tensions that
might otherwise lead to overeating. Exercise builds
physical fitness which in turn builds self-confidence,
enhanced self-image, and a positive outlook. When you
start to feel good about yourself, you are more likely
to want to make other positive changes in your lifestyle
that will help keep your weight under control.
In addition, exercise can be fun,
provide recreation and offer opportunities for companionship.
The exhilaration and emotional release of participating
in sports or other activities are a boost to mental
and physical health. Pent-up anxieties and frustrations
seem to disappear when you're concentrating on returning
a serve, sinking a putt or going that extra mile.
Tips to Get You Started
Hopefully, you are now convinced that
in order to successfully manage your weight you must
include exercise in your daily routine. Here are some
tips to get you started:
- Check with your doctor first. Since
you are carrying around some extra "baggage,"
it is wise to get your doctor's "OK" before
embarking on an exercise program.
- Choose activities that you think
you'll enjoy. Most people will stick to their exercise
program if they are having fun, even though they are
working hard.
- Set aside a regular exercise time.
Whether this means joining an exercise class or getting
up a little earlier every day, make time for this
addition to your routine and don't let anything get
in your way. Planning ahead will help you get around
interruptions in your workout schedule, such as bad
weather and vacations.
- Set short term goals. Don't expect
to lose 20 pounds in two weeks. It has taken awhile
for you to gain the weight, it will take time to lose
it. Keep a record of your progress and tell your friends
and family about your achievements.
- Vary your exercise program. Change
exercises or invite friends to join you to make your
workout more enjoyable. There is no "best"
exercise just the one that works best for you.
It won't be easy, especially at the start. But as
you begin to feel better, look better and enjoy a
new zest for life, you will be rewarded many times
over for your efforts.
Tips to Keep You Going
- Adopt a specific plan and write
it down.
- Keep setting realistic goals as
you go along, and remind yourself of them often.
- Keep a log to record your progress
and make sure to keep it up-to-date.
- Include weight and/or percent body
fat measures in your log. Extra pounds can easily
creep back.
- Upgrade your fitness program as
you progress.
- Enlist the support and company
of your family and friends.
- Update others on your successes.
- Avoid injuries by pacing yourself
and including a warmup and cool down period as part
of every workout.
- Reward yourself periodically
for a job well done!
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