Last updated: Sep 01, 2007

When youre on a mission to lose weight, slashing calories can help in the short term. But new research shows adding physical activity to the mix is what peels away the most stubborn pounds (think belly fat) and keeps them off for good. Those who dont exercise (the Centers for Disease Control says 69 percent of women trying to lose weight dont work out) risk a rebound. Keep reading to find out why that workout is your secret weapon.



Dieting without exercise cant zap the fat. Exercise is just as important as diet if you want to lose belly fat—the kind of fat thats associated with metabolic syndrome, which can lead to heart disease and diabetes—according to a study from Wake Forest University. Researchers found that obese women who dieted for five months without exercise had no changes in abdominal-fat-cell size, while those who combined exercise with diet saw their fat cells shrink by about 17 percent. So a dieter who exercises often has smaller fat cells and a lower risk of heart disease.

Diet alone slows your metabolism. While diets lead to short-term weight loss, studies show that, in most cases, people regain weight. The reason? A slower metabolism. In a new study published in the Journal of Applied Physiology, people who cut 230 calories out of their daily diet for a year but didnt exercise lost muscle mass, strength, and aerobic capacity. And losing muscle is exactly what you dont want to happen when youre trying to lose weight. Exercise (especially strength training) helps you maintain or increase your muscle mass and metabolism, allowing you to burn more fat.


Exercisers stay slimmer. Active people have an easier time maintaining their results over time, says Ann Yelmokas McDermott, PhD, director of the Center of Obesity Prevention and Education and associate professor in kinesiology at California Polytechnic State University. In fact, a study published in the Journal of the American Dietetic Association suggests exercise—even without a diet plan—is more effective for managing weight.

Researchers divided people into three groups, assigning them to try diet only, exercise only, or diet plus exercise. All of them lost weight the first year, but by the second year the diet-only crew gained two pounds over their starting weight. People who exercised weighed an average of five-and-a-half pounds below their starting weight.

The bonus payoff: Dont forget the other benefits of being active—youll enjoy more energy and better overall health. So grab your sneakers and get going.

Starving when you leave the gym?

  • Use this trick to avoid sabotaging your hard work: Exercise can leave you ravenous—and worried about canceling out the calories you just burned with a big meal. That wont happen if you eat the right fuel before and after you exercise, says Ann Yelmokas McDermott, PhD, director of the Center for Obesity Prevention and Education. The mistake, she says, is loading up on refined carbs before a workout. The more muscle you have, the more efficiently your body uses sugar and the bigger your postworkout crash once the sugar rush is gone. And then youre starving!

  • Try this strategy: Instead of reaching for a bagel before you exercise, fill up on fiber-rich foods like oatmeal or an apple to boost your stamina. High-fiber foods give you a steady stream of energy. Go for fiber after your workout, too, and add protein to help build healthy muscles.

  • Bottom line: Make exercise a habit, and youll find it easier to manage your weight for life.