Lift Your Way to Thinness and Fitness

The buff burn more calories than those who work out without weights

SUNDAY, Jan. 6, 2002 (HealthDayNews) -- Women who are beautifully buff have all the luck -- they even burn more calories than the rest of us.

That's the conclusion of a study that found that women who combine aerobics with weight training burn more calories -- even after they've stopped exercising -- than women who opt only for aerobics.

The reason: Muscle's preferred source of fuel is fat, not carbohydrates.

The study compared the women's metabolic levels -- the rates at which they burn calories -- on days they sweated their way through aerobics workouts to days when they coupled aerobics with weight training. Some days, they did aerobics for about 40 minutes, and then were asked to relax in front of the TV. Other days, they followed their aerobics with another 40 minutes of weight lifting.

Two hours after each workout, the researchers measured the metabolic levels. They discovered that on aerobics-only days, the women burned an additional 50 calories, on average, during the two hours after they'd stopped exercising and settled down for some Oprah. Not bad, you might say.

But the real winners in the calorie burn-off were those who went on to lift weights. Two hours after the women shouldered their last weight, they still had dramatically higher metabolic levels -- burning up to 155 calories in the two hours after exercising.

Chief researcher Carol A. Binzen, a clinical exercise physiologist at Johns Hopkins University in Baltimore, lifts weights competitively. She began her research while a faculty member at the University of Arizona, where she watched all the wanna-be thin women at the gym doing only aerobics.

Based on her initial research, she knew aerobics alone isn't enough to lose weight. She says she felt compelled to tell them: "Resistance exercise like weightlifting is cumulative. As you develop more muscle, you burn more calories. Your metabolism is still elevated up to two hours after you lift weights."

Her study, which appeared in a recent journal published by the American College of Sports Medicine, produced other good news, too. While measuring metabolic rates, Binzen also gauged blood lactate levels. These measurements suggested that although the body normally burns carbohydrates and fats equally, after resistance exercise, the body's preferred fuel is fat.

So ladies, lift those weights and feel the burn.

Binzen says the women who were part of her study were all regular women -- "not super-fitness enthusiasts." But duplicating the experiment does require more time and energy than a lot of women devote to exercise.

The regimen calls for 40 minutes of high-intensity aerobic exercise four days a week, followed by 40-minute weight-lifting sessions three days a week.

The weightlifting program includes three sets each of 10 repetitions of chest presses, shoulder presses, leg extensions, leg presses, seated rows, latisimus dorsi pull-downs, biceps curls, triceps extensions and abdominal crunches, using either free weights or exercise machines. The women in the study also used enough weight that by the third repetition, they were at the point where they couldn't do another set.

Lest you think this pain-for-gain is for women only, similar studies have been conducted involving men. One of the studies, by Chris Melby, a professor of nutritional science at Colorado State University, found that serious weight lifters had metabolic levels that were elevated as much as 10 percent up to 24 hours after the last bench press. "Serious" was defined as men who did 90 minutes of relentless weight training at a time.

Melby acknowledges that the men in his study weren't typical. But, he says, less dedicated lifters will also get results. "Even 50 calories a day would add up over the course of a year," he points out.

But more important, both Melby and Binzen believe a combination of aerobic and resistance exercise stays the onslaught of age.

"In the decade from 25 to 35, women can lose 20 percent of their muscle mass. And muscle mass is the metabolic furnace for women," says Binzen.

Adds Melby: "In men, [weight training] preserves muscle tissue, and muscle burns more calories than fat tissue. That changes the slope of the decline attributed to aging."

What to Do: To learn more about weight training, visit the Indiana University Health Center's "Benefits of Weight Training" Web site. Supervised weight training is a big part of the fitness routines offered at most YMCAs. To locate one close to you, go to the Y's national Web site and click on "find your YMCA" at the top of the page.

SOURCES: Interviews with Carol A. Binzen, M.S., C.P.T., clinical exercise physiologist, Johns Hopkins University, Baltimore; Chris Melby, Ph.D., professor of nutritional science, Colorado State University, Fort Collins, Colo.; June 2001, Medicine and Science in Sports and Exercise
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