Study: More Exercise Isn't Always Best
Posted August 20, 2007 6:22 p.m. EDT
Updated August 20, 2007 7:32 p.m. EDT
Durham, N.C. — When it comes to exercise, more isn't necessarily better, according to the findings of a recent study by Duke University researchers.
Moderate exercise, such as walking, provides significant health benefits that can even exceed those gained with more vigorous exercises, such as running.
That finding, however, comes with one important condition, study authors warned.
"You have to spend more time to get the same amount done," said Dr. Cris Slentz, an exercise physiologist.
Researchers divided middle-aged, sedentary people into groups and compared the results each group got from exercising in different amounts and at different intensity levels.
Moderate exericise was more effective than strenuous workouts by some measures, researchers found.
"For lowering triglycerides, moderate intensity is actually better than vigorous exercise," Slentz said.
Triglyceride particles carry fat around the body, and high levels of the particles place people at greater risk of heart disease and diabetes.
Consistent, moderate exercise also raised the amount of the so-called good blood cholesterol in people. Levels of HDL cholesterol, or high-density lipoproteins, improved with the length and intensity of workouts.
Such benefits to moderate exercise are good news to people like Jim Morris. Morris said he doesn't like exercise, but heart bypass surgery last year motivated him to hit the bricks more often.
"I feel better when I'm exercising," Morris said, "But frankly, I'm doing it for the cardiovascular benefits."
Those benefits, including weight loss, increased when people doing workouts repeated them more often and lingered even when participants took a break from exercising, according to study findings.
Such findings should get people out exercising more, Slentz said.
"I would love to get people exercising five days a week, walking 30 minutes each time," he said. "Then, if they can get up to six or seven days a week, I think their benefits will be even greater."
One result of the study didn't surprise Slentz: "Not exercising is not a good option," he said.
In six months, the study group that didn't exercise gained an average of two pounds and expanded their waistlines by half an inch.
Many health benefits of exercise began to disappear after a few days, so researchers do not recommend taking long breaks from exercising.
Morris said the health benefits he has experienced keep him determined to keep exercising.
"I'd like to stay alive," he said, "and I'd like to stay in good health."