Exercise alone won’t help you lose weight, though it conveys an astonishing array of health benefits.

The primary villain when it comes to excess weight is what’s on our menu. To lose weight, we have to cut calories.

“I think the role of exercise in weight loss is highly overrated,” says Marc Reitman, chief of the diabetes, endocrinology and obesity branch of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). “I think it’s really great for being healthy, but I’m a strong believer that overeating is what causes obesity. To exercise your way out of overeating is impossible.”

Agreed, says Michael Joyner, a Mayo Clinic researcher who studies how people respond to the stress of exercise. “The key for weight loss is to generate and maintain a calorie deficit,” he says. “It’s pretty easy to get people to eat 1,000 calories less per day, but to get them to do 1,000 calories per day of exercise – walking 10 miles – is daunting at many levels, including time and motivation.”

Some people can work weight off: those who exercise vigorously for long periods and professional athletes who engage in high-intensity workouts.

But they are the exceptions. Those workouts are “not something most people do,” says Philip F. Smith, co-director of NIDDK’s office of obesity research. “Walking for an hour won’t do it.”

Moreover, moderate exercise doesn’t burn that many calories. A piece of chocolate cake has 200 to 500 calories. Most people burn only about 100 calories for every mile of running or walking. To lose 1 pound, you must cut about 3,500 calories. So if you burn an excess of 500 calories a day, it would take a week to drop that pound.

Kevin Hall, an NIDDK scientist who studies how metabolism and the brain adapt to diet and exercise, agrees that a modest degree of weight loss would require large amounts of exercise.

Still, Hall says, “High levels of physical activity (more than an hour daily) seem to be very important for maintenance of lost weight.”

And you can’t count on exercise to increase your metabolism for several hours afterward.

“Exercise, if hard enough and long enough, certainly can do this,” Joyner says. “But again, it depends on how much, what type and how hard. A 2-mile stroll, while a good thing, will not do too much to resting metabolism.”

The good news: Exercise enhances health in many ways.

It strengthens the heart and lungs. It reduces the risk of Type 2 diabetes and metabolic syndrome, a collection of symptoms that include hypertension, high blood sugar, excess body fat around the waist and abnormal cholesterol or triglyceride levels.

Weight-bearing activities, such as running, strengthen bones and muscles. Having strong bones prevents osteoporosis, helping to avert bone-breaking falls in the elderly. “For older people, exercise facilitates the capacity for them to stay engaged in life,” Joyner says.

Exercise also reduces the risk of certain cancers, including breast and colon cancer. It elevates mood, and it keeps thinking and judgment skills sharp.

Overall, it helps you live longer. People who work out for about seven hours a week have a 40 percent lower risk of dying early compared with those who exercise less than 30 minutes a week, according to the U.S. Centers for Disease Control and Prevention.

Girl prepairing for workout

jelenahinic

Girl prepairing for workout

jelenahinic