News :
Slowpokes burn more calories
US NEWS.COM, June 27 2005 -- The weight-loss
race may go to the speed-challenged tortoise, not the hare, according
to new obesity research. Contrary to much past fitness advice, leisurely
walking—instead of brisk walking—combined with a low-impact cardiovascular
workout, such as biking or swimming, may be a much better formula for
overweight exercisers trying to lose weight than vigorous walking and
high-impact workouts. Strolling about 2 miles per hour actually burns
more calories than the often prescribed brisk 3 mph. Strolling has the
added benefit of reducing impact on the knees by 25 percent.
"We were really surprised," says Ray Browning,
a researcher at the University of Colorado and the lead author of the
study in Obesity Research. "The variable people have been ignoring
is that you are less economical when you walk at a slow speed."
Biology dictates that humans tend to walk automatically at the speed
that conserves their energy the most. If walking a mile at a person's
normal speed takes about 20 minutes, then slowing down means the same
mile takes, say, 25 minutes.
"When you slow down, then you become less efficient
and you walk longer, so you burn more calories," explains Browning,
who adds that leisurely walking is great for people trying to lose weight.
"The key is walking longer." Browning says that most doctors
and obesity experts have advised people to walk briskly because of the
heart benefits. A vigorous walk increases the heart rate, builds heart
muscle, and tends to reduce blood pressure. "The effort of brisk
walking is enough to improve cardiovascular fitness," says Browning.
"But there's another side to the equation. And that's the need
to minimize the risk of musculoskeletal injuries while using more calories.
What we found is that obese women, for example, who do brisk walking
for exercise have seven times the risk of developing osteoarthritis
of the knee." Browning and his Colorado colleagues believe the
medical community's exercise prescription, certainly for most overweight
or obese folks, may need an overhaul. "We're creating the public
health perception that what people have to do is go out and walk briskly
for 60 to 90 minutes, and most people just can't do it, and if they
do, lots of them get injured." The Centers for Disease Control
and Prevention reports that some 25 percent of sedentary people who
begin a brisk walking program, end up injuring themselves. Ironically,
many return to sedentary lives. "And here the whole idea was to
increase physical activity," laments Browning. "So what we're
recommending is that rather than overweight people using brisk walking
as their primary form of exercise, slow walking is great for burning
calories while protecting the joints. Then, use other forms of low-impact
aerobic activity—cycling, swimming, or elliptical training—to get the
heart rate up and increase cardiovascular fitness."
An avalanche of medical studies have pretty much proved
that exercise confers a variety of benefits no matter what people's
weight. But finding the safest way for the majority of couch potatoes
to get active is the newest challenge facing obesity experts. Browning's
research points in a new direction. Maybe that old custom of a leisurely
stroll after dinner was better for one's health than anybody thought.
(source : www.usnews.com)
