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Common Myths about
Getting and Staying Fit
Myth #1: While light exercise
does yield some benefits, it's not nearly as beneficial as strenuous
exercise.
Truth: Strenuous workouts do improve aerobic capacity far more
than light or moderate workouts do. While that may improve athletic
performance, it does not necessarily translate into a great health
advantage.
The death rates from coronary heart disease, cancer, and all causes
combined are much lower in moderate exercisers than in non exercisers;
but they're only a little lower in heavy exercisers than in moderate
exercisers. The same holds true for the risk of developing type II
diabetes, by far the most common kind.
In addition, non strenuous exercise seems to reduce stress, anxiety, and
blood pressure as effectively as strenuous exercise does. And moderate
exercise like walking can do just as much to control weight as vigorous
exercise like jogging, since the number of calories burned depends on
how much ground you cover, not how fast you cover it. In fact, moderate
exercise is potentially more effective than vigorous for most people,
since they can walk much further than they can run.
Myth #2: You can lose fat from specific parts of your body by
exercising those spots.
Truth: There's no such thing as "spot reduction." When you
exercise, you use energy produced by burning fat in all parts of your
body - not just around the muscles that are doing most of the work. In
fact, your genes may dictate that fat disappears from, say, your face or
arms before your belly, even if you do endless abdominal exercises.
However, working a specific region like the belly can have one
site-specific benefit: Strengthening the muscles can make you look
thinner by helping you hold in your gut.
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Myth
#3: The more you sweat during
exercise, the more fat you lose.
Truth:
The harder you work out, the more calories you'll burn within a given
period and thus the more fat you stand to lose. But how much you sweat
does not necessarily reflect how hard you're working. Some people tend
to sweat profusely due to heavy body weight, poor conditioning, or
heredity. And everyone sweats more in hot, dry weather or dense clothing
than in cool, humid weather or porous clothing. (You may feel as if
you're sweating more in humid weather; but that's because moist air
slows the evaporation of sweat.)
Exercising in extremely hot weather or in a plastic "weight loss" suit
will indeed make you sweat heavily and lose weight immediately. But that
lost weight is almost entirely water; the pounds will return when you
replenish your fluids by drinking after the workout. Further, you could
develop heat exhaustion if you push yourself too hard in extreme heat or
in plastic clothes. which prevent sweat from evaporating and, in turn,
cooling you off.
Myth #4:
Sports drinks can help you exercise more safely and effectively.
Truth:
Sports drinks contain two main ingredients that are theoretically
beneficial for exercisers: sodium, which helps the body retain water,
and sugar, which the body burns for energy. But very few people exercise
hard enough to sweat away much sodium or to use up their carbohydrate
reserves, which the body converts to sugar. You'd have to jog for at
least two hours, for example, before your carbohydrate stores would
start to run low. So unless you're doing a marathon or other exhaustive
exercise, plain water is all you need.
Myth #5:
Aerobic exercise tends to make you hungry, so it actually undermines
your efforts to lose weight.
Truth:
Aerobic exercise, such as jogging or brisk walking, may indeed increase
your appetite - but only, it seems, if you need extra calories. Studies
suggest that lean individuals do get hungrier after such exercise; that
helps prevent them from getting too thin. In contrast, working out does
not seem to boost appetite in obese individuals; so exercise should help
them slim down.
Myth #6:
Strength training won't help you get thinner, since it burns few
calories and adds pounds of muscle.
Truth:
Strength training, using either weights, machines, or elastic bands, can
substantially increase the number of calories you burn. A typical
session, in which you rest briefly after each muscle-building maneuver,
uses up calories at least as fast as walking does. Circuit training, in
which you move quickly from one strengthening maneuver to the next,
burns calories faster than walking does. And your body continues to burn
calories for hours after either type of strength training. More
important, the muscle you build consumes calories more rapidly, even
when you're not exercising.
In one study, three months of strength training boosted the average
calorie-burning rate by an average of 7 percent, burned off 4 pounds of
fat, and added nearly that much muscle. Since muscle is denser than fat,
the volunteers presumably did become thinner. Equally important, they
burned off that fat despite a 15 percent increase in their calorie
content. If the researchers hadn't prodded them to maintain their weight
by eating more than they felt like eating, the volunteers almost surely
would have lost weight.
Strength training is particularly helpful as part of a comprehensive
weight-loss program that includes both aerobic exercise - which burns
lots of calories during the workout and some calories after the workout
- and a moderately low-calorie diet. (forget crash diets, which almost
always never work and can be dangerous.) A recent study found that women
who ate a moderately restrictive diet and did either strength training
or aerobic exercise lost more weight than those who only dieted. But
those who split their workout time between strength training and aerobic
exercise lost the most weight of all.
Myth #7:
Strength training builds muscle and bone but does nothing for the heart.
Truth:
Strength training plus aerobic exercise may be the ideal exercise
regimen not only for the waistline but also for the heart. One analysis
of 11 clinical trials found that strength training can reduce levels of
LDL cholesterol, the artery-clogging kind (though it has little effect
on HDL cholesterol, the artery-clearing kind). Aerobic exercise has a
complimentary benefit: It improves HDL but does little for LDL. Further,
some studies suggest that strength training, like aerobic exercise, may
help reduce blood pressure. (But check with your doctor for guidance
before starting a muscle-building program if you have hypertension,
since straining can temporarily increase blood pressure.) One final
benefit: By fortifying the muscles, strength training reduces the
likelihood that sudden or unaccustomed exertion, such as moving
furniture or shoveling snow, will trigger a heart attack.
Myth #8:
When you stop exercising, your muscles turn to fat.
Truth:
Lack of exercise does make the muscles shrink, reducing the body's
calorie-burning rate. The lack of activity itself further reduces the
number of calories you burn. So people who stop working out are indeed
in danger of getting flabby.
But that doesn't mean that muscle actually turns to fat - they're
totally different types of tissue. Nor does it mean you're doomed to
gain fat around the muscles after you stop exercising; you just need to
cut back on the calories you consume. (Of course, the best way to stay
slim is to eat a lean diet and continue to exercise regularly.)
Myth #9:
Building muscles reduces flexibility.
Truth:
If you strength train without moving your joints through their full
range of motion, you can indeed lose flexibility. But strength training
can actually improve flexibility if you do move your joints fully.
Stretch after a muscle-building workout to help keep yourself limber.
(Stretch before as well as after an aerobic workout.)
Myth #10:
Strength training tends to give women a bulky, masculine physique.
Truth:
It's very difficult for most women to build large muscles. That's
because women have relatively low levels of the hormone testosterone,
which influences muscle growth. Both men and women can build firmer
rather than bulkier muscles by working against lighter resistance more
than 25 times rather than heavier resistance fewer times.
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