Countless studies have shown that people who are physically fit, at any age, have a reduced risk of most chronic diseases and improved quality of life. A growing body of research is extending the time frame and finding that being fit in middle age can have a big payoff even two or three decades later. Some of the best evidence for this, including the two recent studies discussed below, comes from the Cooper Institute in Dallas, which has a large database on patients who have gone to its preventive medicine clinic since 1970.
- Chronic illnesses. In a study published in the Archives of Internal Medicine in September, researchers analyzed data from more than 18,000 healthy people whose baseline cardiorespiratory fitness level was assessed via a treadmill test when they were in their forties or fifties. By examining Medicare claims, they found that subjects who were most fit initially were much less likely to develop cardiovascular disease, Alzheimer’s, diabetes, kidney disease, colon or lung cancer and other chronic illnesses during the next 20 to 30 years, compared to their less-fit counterparts. Moreover, the fittest people tended to experience a “compression of morbidity” at the end of their lives, meaning that illness was delayed and then compressed into a shorter period before death. That is, even when they didn’t live longer, they had more healthy years.
- Dementia. More recently, in a study published in the Annals of Internal Medicine, the same researchers focused on dementia, including Alzheimer’s disease. People who were fittest in mid-life were found to be one-third less likely to develop dementia in their seventies and eighties than those who were initially the least fit. Cardiorespiratory fitness may help prevent dementia by reducing the risk of diabetes and hypertension, both of which can contribute to dementia. Still, the benefit of being fit remained even after the researchers controlled for such factors. Physical activity and fitness also have direct effects on the brain that lower dementia risk—reducing brain shrinkage, for instance. As the accompanying editorial concluded, fear of Alzheimer’s may motivate people to heed advice to exercise, which is “a reasonable prescription for dementia prevention.”
Get into the habit: One benefit of exercising in middle age is that it increases the likelihood that you’ll continue to exercise in later life. And it tends to go along with other good habits, like eating healthy foods and not smoking. Still, if you’re past middle age and didn’t exercise much back then, you didn’t miss the train—you can still hop on at the next station. Research shows that it’s never too late to start.