Study finds vigorous exercise lowers death risk from all types

WASHINGTON -- Physically fit people are less likely to die of cancer, including cancers related to smoking, even if they smoke, a study finds.

But other studies indicate the benefit may come only with vigorous exercise; less-intense activities, such as brisk walks, won't be enough.

"Fitness may provide protection against cancer mortality," said the study, which was in the journal Medicine and Science in Sports and Exercise.

The researchers followed 25,892 men ages 30 to 87 who took treadmill tests to determine the most exercise they could do. The men were followed for an average of 10 years. In this time, there were 133 deaths from cancers related to smoking and 202 deaths from other cancers.

The most-fit men had a 55 percent lower risk of all-cause cancer death than did low-fit men, and moderately fit men had a 38 percent lower risk, said researchers Chong Do Lee of West Texas A&M University and Steven N. Blair of the Cooper Institute of Dallas.

The most-fit men were least likely to smoke, but almost 10 percent of them did, as did 20 percent of moderately fit men and 33 percent of sedentary men. The most-fit and moderately fit smokers were still less likely to die than were the sedentary smokers, Lee said.

Just the same, Lee and other experts say exercise is no substitute for giving up smoking.

The researchers theorized that the heavy breathing that comes with vigorous activity clears the lungs of some cancer-causing chemicals associated with smoking. And fitness may help the body in other ways, such as improving defensive systems that may keep tumors from forming, they said.