Greater Fitness in Old Age Correlates with Greater Ten Year Survival Rates

The research materials here make a good companion piece to a recent study showing that exercise performance, physical fitness in other words, predicts mortality more accurately than age. In the study here, much the same analysis is carried in a different patient population, a sizable group with an average age of 75 at the study outset. Ten years after fitness testing was carried out, mortality data for the study population shows that those of greater fitness were significantly more likely to survive. We shouldn't need any more incentives than already exist to stay active and fit for as long as we can in live, but add this one to the mountain of evidence on the topic.

Doctors use cardiovascular risk factors to help guide decisions about preventive measures and medications. Previous studies have shown that quitting smoking and controlling blood pressure, cholesterol, and diabetes can reduce heart disease risk. However, most studies of cardiovascular risk factors have focused on middle-aged people, leaving a knowledge gap regarding the importance of these risk factors in older people.

The team analyzed medical records from more than 6,500 people aged 70 years and older who underwent an exercise stress test between 1991 and 2009. They assessed fitness based on patients' performance during the exercise stress test, which required patients to exercise on a treadmill as hard as they could. They divided patients into three groups reflecting their fitness based on the number of METs (metabolic equivalents, a measure of exercise workload) they achieved during the test: most fit (10 or more METs), moderately fit (six to 9.9 METs) and least fit (six or fewer METs). For this study, the researchers grouped patients with zero, one, two, or three or more cardiovascular risk factors.

On average, participants were 75 years old when they underwent the stress test. Researchers tracked the patients for an average of just under 10 years, during which time 39 percent of them died. Over this period, the researchers found higher fitness was associated with significantly increased rates of survival. The most fit individuals were more than twice as likely to be alive 10 years later compared with the least fit individuals. In contrast, a patient's total number of cardiovascular risk factors was not associated with their risk of death and patients with zero risk factors had essentially the same likelihood of dying as those with three or more risk factors. The study did not account for any changes in fitness level that the participants may have experienced over time. However, previous studies have suggested that improving fitness can help improve heart health, even late in life.