Middle-aged adults who regularly walk or even garden are much less likely to die in the next eight years than their couch potato counterparts, even if they are at high risk for heart attack or stroke.

Researchers reporting in the November issue of the journal Medicine and Science in Sports and Exercise have found that physically active 50- and early 60-year-olds are 35 percent less likely to suffer an early death than those who were sedentary.

The reduction was even more pronounced in smokers and patients with cardiovascular disease (search) (CVD) factors, such as diabetes or high blood pressure. People in that group who exercise regularly cut their risk of early death by 45 percent.

"We found that across all ranges of cardiovascular risk, everybody got a benefit from regular activity, but the biggest absolute benefit, the biggest reduction in death, was among high-risk people," lead researcher Caroline Richardson, MD, an assistant professor of family medicine at the University of Michigan, says in a news release.

For the study, researchers analyzed physical fitness data from more than 9,000 older, non-institutionalized adults aged 51 to 61. They were asked how often they engaged in exercise. Those who answered "never" or "rarely" were considered sedentary; adults who worked out moderately or at least three days a week were characterized as regular exercisers. Patients who fell in the middle were classified as occasional exercisers.

The participants were also grouped into having a low, medium, high risk of heart disease. This was based on the numbers of medical conditions or lifestyle habits each patient had, such as smoking, high blood pressure (search), diabetes (search), a history of heart disease, or a history of stroke. People with two or more of these were considered to be at high risk of heart disease.

In all, 810 people died at the end of the study. Those with the highest heart disease risk were more than four times more likely to die as those with the lowest risk.

However, 27 percent of the non-exercising, high-risk adults had passed away, which was almost twice the percentage of their peers with similar risks who kept physically active.

Though numerous studies have examined the long-term benefits of exercise, this is the first to consider different population groups and heart disease risks "to see who got the most 'punch' out of exercise," says Richardson.

The authors say their findings underscore the need for making exercise a priority among sedentary patients, especially those with high heart disease risks, and conclude that the benefits of physical activity most likely outweigh the risks of remaining sedentary for the majority of high-risk patients.

By Kelli Miller Stacy, reviewed by Brunilda Nazario, MD

SOURCES: Medicine and Science in Sports and Exercise, November 2004; vol 36: pp. 1923-1929. News release, University of Michigan.