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Is weight gain an inevitable
part of growing older? It certainly seems so. Overall, one of every
two American women is overweight or obese. The age related upward
drift is clear: Among women in their twenties, one-third are overweight
or obese. The proportion jumps to just over one-half among women
in their forties and nearly two-thirds among women in their sixties
and seventies.
Overweight
doesnt just mean a few pounds. For a 54 woman,
overweight translates to 145 to174 pounds. Obese would be defined
as 175 pounds or more for this same woman. Being overweight is associated
with a myriad of health problems, including type two diabetes, hypertension,
gallstones, and osteoarthritis.
Whats behind this
mid-life obesity? Theres no question that our all-American
lifestyle, which encourages eating more and moving less, doesnt
help. It is also important to recognize that our metabolism plays
a crucial role. The truth is that our basal metabolic rate (BMR),
the rate at which our body uses energy (calories) to stay alive,
typically decreases as we age. This metabolic slowdown is caused
by aging-related changes in our body composition.
After age 30, we lose
muscle mass each decade. Starting at age 40, the average woman loses
six to eight percent of her muscle mass per decade. This lost muscle
is replaced by fat.
Muscle burns calories
even at rest, but fat does not. As a result, replacing muscle mass
with fat means that the number of calories we need each day drops
as well, not catastrophically, but enough to make a difference over
time. This makes it all too easy for us to take in more calories
than we burn, and the pounds creep on.
The good news is that
its possible to reverse this trend. However, doing so requires
making a real commitment to exercise. Theres no question that
we need to watch what we eat; calories always matter. Dieting alone
wont solve the central issue: an increasingly sluggish BMR.
Moreover, dieters who dont exercise often lose muscle mass
along with the fat, only adding to the BMR problem and almost guaranteeing
that the lost weight will return.
What kind of exercise
is best for avoiding midlife weight gain: aerobic exercise or lifting
weights? You really need both. You cant just do one or the
other.
It takes cardiovascular
exercise to burn calories during the actual time you exercise; but
it takes muscle mass to burn calories throughout the day and only
resistance training can put back the muscle mass.
How much exercise is
enough? The recommended amount is 30 minutes of moderate activity
on most days of the week, but thats just the bare minimum
for basic health purposes. Recent studies suggest that to lose weight
and keep it off, you need to rack up considerably more activity
than that. On average, people who have lost weight report that they
burn about 2,800 calories per week in exercise.
If that seems like an impossible task, remember that this covers
all activity not just formal exercis e
sessions. Every bit of activity counts, from taking the stairs at
work to weeding the garden and walking the dog.
With strength training,
the general recommendation is to do two to three sessions per week,
with a day off between each session to give your muscles time to
recover and repair. If you dont care for lifting weights,
you may want to try yoga or Pilates mat classes. Both use the weight
of your own body to provide resistance.
However you choose to
blend formal aerobic exercise, strength training, and just plain
getting up and going, remember: The more you add in resistance training,
the easier it is to manage mid-life weight gain.
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