Quoted message said:From The New York Times this morning.
http://www.nytimes.com/2005/07/21/fashion/thursdaystyles/21Fitness.html?July
21, 2005
Weight-Loss Theory Is Losing Some of Its Strength
By MARTICA HEANER
BARBARA WOODWORTH, 35, a social worker in Seattle, wanted to drop 40
pounds. Alisa Rivera, 39, a college adviser at the University of
California, Los Angeles, also wanted to lose weight. She also wanted to
build long, lean muscle. So the two women routinely began to lift
weights. But like many of the other 36 million women nationwide who
each year pick up dumbbells hoping to lose pounds or develop a
sculptured body, both Ms. Woodworth and Ms. Rivera ended up
disappointed because the strategy is not as simple - or as effective -
as it sounds.
Personal trainers, fitness instructors, magazines and books have sold a
double-barreled promise that any strength training builds muscle and
that having more muscle dramatically speeds metabolism, increasing the
calories a person burns while at rest. With all that extra calorie
burning, the story goes, excess weight comes off effortlessly.
The story is wrong in two ways, researchers say. First, muscle is not
such an amazing calorie burner. "Even if weight training increases
muscle and metabolism, there is little evidence showing that it is
enough to cause weight loss," said Joseph Donnelly, the director of the
Energy Balance Laboratory at the University of Kansas, who has
extensively reviewed studies on the link between resistance training
and weight loss.
And second, many who try weight training - especially women - fail to
do what it actually takes to build more muscle. They lift too light a
weight, or they neglect to progress to heavier weights as they grow
stronger. And often, women who take up weight lifting also diet. In
fact, it is nearly impossible to increase muscle while cutting
calories.
Regular resistance training, done correctly, has many benefits. It can
prevent some of the muscle loss that occurs with weight loss. It can
also lower body fat levels and even help preserve bone mass. But the
idea that it can magically increase calorie-burning is "a very big
stretch," said Edward Melanson, an assistant professor in the division
of endocrinology, diabetes and metabolism at the University of Colorado
Health Sciences Center in Denver. Claims that resistance training can
send metabolism skyrocketing are easy to find. A Google search using
the terms "metabolism" and "weights" produces thousands of Web sites,
many of which say that anyone can lose weight and build muscle through
strength training, even doing routines that aren't particularly
strenuous.
Books like Kathy Smith's "Lift Weights to Lose Weight" also perpetuate
the myth that building muscle supercharges metabolism and quickly leads
to weight loss. In "Smart Girls Do Dumbbells," Judith Sherman-Wolin
claims that resistance-training can "melt away those stubborn pounds
you've been trying to lose all your life." And Jorge Cruise's best
seller, "8 Minutes in the Morning," advises readers to forget aerobics
or grueling workouts because doing his two strength-building exercises
a day "will help you firm up five pounds of lean muscle within the
first few weeks, allowing your body to burn an extra 250 calories per
day." Ms. Woodworth of Seattle said, "Practically every fitness book
and magazine I ever read said strength training boosts metabolism so
you lose weight easier and faster."
Before taking up weight lifting, she had already lost 15 pounds in
about three months by cutting calories and walking and running for an
hour three times a week. With 40 pounds still to shed, she turned to
what she had heard was the magic bullet.
Her trainer advised her to lift four times a week, cut her
cardiovascular exercise to less than 30 minutes but still keep dieting.
After six weeks, she was frustrated to find she had gained two pounds.
That added weight probably wasn't muscle. Decreasing her
high-calorie-burning walks and runs was the more likely culprit.
Lifting weights burns few calories - "at least the way the average
nonathlete does it and certainly the way most women tend to do it,
using relatively low weights and few sets," Dr. Donnelly said. The same
time spent an aerobic workout could double the calorie burn.
Once Ms. Woodworth increased her time on cardio, she lost the added
weight.
Proponents of the theory that weight lifting leads to weight loss argue
that it is the long-term effect of gaining more muscle, which burns
more calories at rest, that causes weight loss. Still, that has never
been proven in studies.
Studies show that even women who do what it takes to get stronger
develop only two to four pounds of muscle after six months of
progressive lifting. Given that one pound of muscle burns between 7 to
13 calories a day (as determined by studies that measured oxygen and
blood flow to tissues), that means the average boost in metabolism is
only 14 to 52 calories a day, said Dympna Gallagher, the director of
the body composition unit at the New York Obesity Research Center in
Manhattan.
The effect of weight lifting "on metabolism is minor and certainly not
the savior of dieters," said William Kraemer, a professor of physiology
and neurobiology at the University of Connecticut.
A recent yearlong study of 59 sedentary women at the University of
Pittsburgh demonstrated what little difference weight training can make
in weight loss. About a third of the women lifted weights three times a
week, another third did yoga three times a week, and the last third did
neither. All the women followed a daily diet of 1,200 to 1,500 calories
for the entire year and walked five days a week. In the end, those who
had lifted weights or practiced yoga lost as much weight and fat - but
no more - than those who only dieted and walked.
Surprisingly, many of the women became no stronger. "We were looking at
whether women would stick to the routine, and if so, would they
resistance train intensely enough," explained Kara Gallagher, the lead
researcher. "It appears that many did not."
When people lift light weights and fail to progressively increase the
load, they only increase endurance, Dr. Kraemer said.
After turning "doughy," Ms. Rivera of Los Angeles followed a few
workouts using five-pound weights that she'd seen in Glamour and Shape
magazines. "After three months the scale hadn't budged," she said. "I
didn't see much of a difference in muscle tone."
Eventually she realized that light weights were not enough. "When I
progressed from a five-pound dumbbell and began to lift heavier, my
arms and butt got firmer within three weeks, although I still did not
lose weight," she said.
For those looking to build a more sculptured body, dieting may be
counterproductive. "To create new muscle tissue you need to eat enough,
not cut calories, to fuel the process," said Karen Reznik Dolins, the
director of nutrition at Altheus, a sports center in Rye, N.Y., and a
nutrition adviser to the New York Knicks.
Genetics can also help determine the impact that weight lifting can
have on muscle development and metabolism.
Researchers at the University of Massachusetts at Amherst looked at
almost 600 men and women who did a strenuous, progressive resistance
routine for three months, according to a study in this month's Medicine
& Science in Sports & Exercise. Three percent were "high responders,"
some of whom doubled their strength. One percent were "low responders,"
who became only 1 percent stronger than they were when they started.
The majority of men and women increased muscle size 15 to 25 percent;
and most men improved their muscle strength 40 percent while women
increased theirs 65 percent.
Shannan Catlett, a fashion sales executive in Manhattan, said lifting
heavy weights helped tone her slimmer body. After she lost 50 pounds by
using the elliptical machine and treadmill and by following a healthier
diet, she improved her muscle definition with weights.
"I never lost weight from strength training, but my butt got smaller
and I got stronger and firmer all over," Ms. Catlett, 41, said. "I
still have to make sure that I'm always fit in regular cardio to
maintain my weight."
Copyright 2005 The New York Times Company Home Privacy Policy Search
Corrections XML Help Contact Us Work for Us Back to Top
