To have a better life, get a little exercise. To have a longer life, sweat a little more - and step up the pace, researchers reported Wednesday.
The latest in a spate of seemingly conflicting studies found that to extend your life, you must exercise vigorously, not just moderately.For years, that was exactly what fitness gurus preached. Then research began showing that moderate activity helped people's health. Many exercise advocates - including the government's Centers for Disease Control and Prevention - started encouraging millions of couch potatoes to get up and do anything at all.
Now a study in Wednesday's issue of The Journal of the American Medical Association says moderate activity won't boost longevity.
Researchers examined 26 years of data on 17,321 healthy male Harvard alumni who graduated between 1924 and 1954.
"We found that only vigorous exercise was associated with lower mortality, and nonvigorous exercise did not at all reduce mortality rates," said Dr. I-Min Lee, an assistant professor of medicine at Harvard.
Lee hastened to add that moderate exercise has many other benefits - improving quality of life, promoting physical well-being, enhancing the ability of older people to accomplish daily tasks, regulating blood pressure and averting diabetes.
"I don't want to dissuade couch potatoes from exercising," Lee said in a telephone interview. "I strongly believe that any exercise is better than no exercise. But for persons who can exercise at a higher level, why not do that? Because our data indicate they might live longer than other people."
Step up the pace
Examples of how much vigorous activity was needed to reduce by 25 percent the chance of dying over a 26-year period:
-Walking briskly, 4 to 5 mph, for at least 45 minutes a day, five days a week.
-Jogging for at least an hour three times a week.
-Playing tennis for a least an hour three times a week.