Why Exercise May Be More Important than Body Fat

Keeping body fat in check and getting plenty of exercise are both proven ways to improve health. But the latter may help you recover faster after a stroke, a new study suggests.

The new research, published online in the journal Neurology, found that people who exercised vigorously—defined here as playing sports, doing heavy housework or working a job that requires physical labor—at least three times a week were more likely to be independent both before and after having a stroke, compared to people who exercised less.

No similar pattern was seen for body mass index (BMI), a measure of body fat based on height in relation to weight. “If people were obese or overweight, it didn’t really tell us much about how they’d do after a stroke,” says lead author Pamela Rist, an associate epidemiologist at Brigham and Women’s Hospital.

The study followed more than 18,000 adults ages 50 and older for an average of 12 years. Every other year, people were interviewed about their height, weight and whether they exercised regularly, as well as their ability to perform basic self-care and household functions.

No one had ever had a stroke before the study began, but 1,374 people experienced one (and survived) throughout the study period.

Three years after their strokes, survivors who had been less active at the start of the study were 18% less likely to be able to do basic self-care functions like bathing, eating and getting in and out of bed compared to those who had been regular exercisers. “If you’re physically active beforehand, it may improve your ability to do those physically demanding acts as you recover,” says Rist.

Those who hadn’t exercised three times a week were also 16% less likely to be able to do more complex activities, such as managing money and grocery shopping, three years after their strokes. “These tasks are more cognitively demanding,” says Rist. “One of our hypotheses is that maybe physical activity helps you maintain cognitive functioning, in addition to physical functioning, after a stroke.”

The study can’t prove that exercise is responsible for these effects, and the researchers found no evidence that physical activity actually slowed the rate of functional decline. Researchers saw differences in the independence levels of people who exercised, versus those who did not, three years before people’s strokes occurred. Some people may have had disabilities at the start of the study that prevented them from being active, they note.

And while being obese did raise a person’s risk of having a stroke in the first place, getting too little physical activity did not. About 45% of people who did not have a stroke were regular exercisers, but so were 43% of those who had a stroke and survived. However, only 26% of the people who had a stroke and died were physically active on a regular basis.

The results suggest that people should be paying “at least as much attention” to their exercise habits as they do to their weight, Rist says. “You certainly shouldn’t ignore your weight, but in this case it does seem like physical activity is a bigger indicator of how well you may recover if a stroke does happen,” she says.