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Pump Up The Metabolism
By Wayne L. Westcott |
 Quincy
- Muscle and metabolism are closely associated.
Increasing muscular activity correspondingly raises
metabolic rate. This makes sense because more physical work
requires more energy and energy production is the major role
of the metabolism.
Muscle tissue, however, is metabolically active even when it
is at rest. Due to ongoing tissue remodeling, muscles use 25
percent of the calories burned while sleeping. It therefore
follows that muscle loss has a negative effect on resting
metabolic rate and muscle gain has a positive effect on
resting metabolic rate. Adults who do not strength train
lose about five pounds of muscle every decade, which leads
to approximately a 3 percent per decade reduction in resting
metabolism.
Assuming a resting metabolic rate of 1,500 calories per day,
a 3 percent decrease means about 45 fewer calories used on a
daily basis. These unused calories are stored as fat and are
largely responsible for the obesity epidemic in the nation.
Many people think that metabolic slowdown is an inevitable
consequence of the aging process, but it is not. In fact,
adding muscle and increasing resting metabolism can take
place at any age.
In 1994, a classic study on muscle and metabolism was
conducted at Tufts University. Senior men and women
performed about 30 minutes of strength training (three sets
of four exercises) three days a week for 12 weeks. They did
no other physical training during the research period. After
three months, the study participants added 3.1 pounds of
muscle and increased their resting metabolic rate by 6.8
percent. They concurrently lost four pounds of fat even
though they progressively ate more calories on a weekly
basis throughout the study.
That same year, a similar study was conducted at the
University of Maryland. Older men performed approximately 30
minutes of strength training (one set of 14 exercises) three
days a week for 16 weeks. They did no other physical
training during the research period. After four months,
these participants added 3.5 pounds of muscle and increased
their resting metabolic rate by 7.8 percent. Like the Tufts
University research subjects, they concurrently lost four
pounds of fat.
Based on the results of theses studies, it is clear that
regular strength training increases muscle mass and
metabolic rate. While it is tempting to think that the new
muscle is responsible for raising resting metabolism, this
is only partly true. In effect, all of the exercised muscle
(50 to 80 pounds in an average adult) contributes to the
metabolic increase. Assume that strength training raises
your resting metabolic rate 6.8 percent, from 1,500 calories
per day to 1,600 calories per day. Every day, you are
burning 100 more calories at rest than before you started
strength training. This is really an amazing benefit of
regular resistance exercise, and one that most people don’t
realize.
In fact, many adults avoid strength training because they
believe it will increase their bodyweight. While strength
training does rebuild muscle, it typically leads to fat loss
due to the higher resting metabolism.
In our unusually large 2009 study, the 1,644 participants
added 3.1 pounds of muscle and lost 3.7 pounds of fat after
10 weeks of strength training. These are essentially the
same results as those in the Tufts University and University
of Maryland studies, confirming the body composition
benefits of sensible resistance exercise. If you want to
remodel your muscle, recharge your metabolism and reduce
your fat, strength training is the perfect activity. By
doing 20 minutes of strength exercise two or three days a
week, you should experience all of these advantageous
adaptations.
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About The Author
Wayne L.
Westcott, PhD, teaches exercise science at Quincy College
and consults for the South Shore YMCA. He has authored 24
books on strength training and fitness.
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