Guidelines: Exercise more, not harder

You can run it, walk it or crawl it, but when it comes to the health benefits, a mile is just a mile.

That's the main message the government is likely to include in recommended exercise guidelines it will issue later this year as a complement to its famous food pyramid.

"Despite the fact that there has been a national policy with respect to nutrition for years, there has never been any national policy with respect to physical activity," said Dr. William Kraus, a Duke University cardiologist and professor of medicine, one of 13 fitness experts who helped compile information for the guidelines.

Kraus said the resulting 638 pages of recommendations can be summarized in a few essential points. Basically, don't sit around all day, and when you do move, you don't have to go at breakneck speed -- welcome news to mall walkers everywhere.

"It appears that the most important parameter is how much exercise you do, NOT how hard you do it," Kraus said.

This may seem hard to believe, because running gets the heart pumping much more quickly than walking. But running a mile raises the heart rate for only about five to 10 minutes. Walking a mile elevates the heart rate less than running, but can do so for twice as long.

"Whether you walk a mile, jog a mile or sprint a mile, it burns about 100 kilocalories," with the same health benefits, Kraus said.

In fact, for some benefits, particularly glucose control, walking could be better than running.

Kilocalories, which are conventionally referred to simply as calories, are units of energy -- such as the energy stored in food and used during exercise. Consuming more calories than we burn can result in weight gain and health problems.

Ideally, the average American should be walking, jogging or running about nine to 10 miles a week, Kraus said. The pace affects only how quickly you want to get it over with.

Adding wheels or water changes things. To get the same benefits as walking or running one mile, you would have to bicycle five miles, or swim only one-fifth of a mile. For example, if bicycling were the exercise of choice, the average American should bike 45-50 miles a week to keep healthy and maintain weight. A swimmer would need to put in only about 2 miles a week.

Such exercise, on top of normal everyday activities, adds up to approximately the number of calories consumed in a week, assuming a 2,000-calorie-a-day diet.

To lose weight, added Kraus, one simply needs to offset the caloric balance by consuming fewer calories than are burned. A pound is about 3,600 calories, so to lose a pound a week you can either cut those 3,600 calories out of your diet, or burn those 3,600 calories on top of your regular physical activity regimen.

Jeannine Taylor, 73, has been walking for exercise in the Cary Towne Center since the late 1980s. She was thrilled to know her form of exercise is as beneficial as more-strenuous activities.

"I have a son-in-law who does triathlons," said Taylor, as she sat with her husband and a friend in the mall food court. "Next time I see him, I can't wait to tell him that what I'm doing is just as good as what he's doing."

She knew that

Mary Pierce is 81 years old, and has been walking the mall for 25 years. Pierce was unfazed by the advisory council's conclusions.

"Of course, walking is good for you," she said. "I'm healthy as a horse. I haven't had a cold in 25 years."

And the benefits of physical activity are not restricted to weight loss or cardiovascular health. The advisory committee examined a number of physical concerns, including cancer, diabetes, bone density and heart disease. Across the board, health benefits increase with the volume of exercise done, not the intensity.

Not everyone is convinced that crafting universal health guidelines is worthwhile. Dr. Nortin Hadler, professor of medicine at UNC-Chapel Hill, sees it as a preoccupation with "the minutiae of lifestyle issues," which neglects to take into account an individual's circumstances, such as poverty or diet.

"Western society has been medicalizing fads for centuries," he said. "This year, if you give your child margarine, you're a criminal; last year, if you gave them butter, you were a criminal."