At a certain age, most people start to worry about being able to live on their own, showering, shopping, cooking and getting around without assistance. Protecting your independence may be easier than you think, a Northwestern University study finds. In fact, it can take less than 10 minutes a day.

This is good news for people who find it painful to move because of conditions like osteoarthritis. It is estimated that 14 million older adults in the U.S. show symptoms of knee osteoarthritis, the most common form of osteoarthritis. Among those with osteoarthritis, roughly two in five people will develop limitations in their ability to get around.

Just one hour of exercise each week cut the risk of disabilities related to activities of daily living —such as walking across a room, bathing and dressing — by almost 45 percent.

Researchers analyzed four years of data from more than 1,500 adults in the national Osteoarthritis Initiative. Everyone in the study had pain, aching or stiffness in the joints of their legs or feet from osteoarthritis, but were free of disability when they started the study. Their physical activity was monitored using accelerometers.

The study found an hour of weekly moderate-to-vigorous physical activity allowed older adults to maintain their ability to perform daily tasks like getting dressed or crossing a street before a traffic light walk signal changed.

“This is less than 10 minutes a day for people to maintain their independence. It's very doable,” said lead author, Dorothy Dunlop, professor of preventive medicine at Northwestern University Feinberg School of Medicine, in a statement.

One hour of exercise a week reduced a person's risk of mobility disability — walking too slowly to safely cross a street or less than one meter per second — by 85 percent. It also cut the risk of disabilities related to activities of daily living such as walking across a room, bathing and dressing, by almost 45 percent. Four years after the start of the study, 24 percent of adults who did not get the weekly hour of brisk physical activity were walking too slowly to safely cross the street, and 23 percent reported problems performing their morning routine.

Older adults with osteoarthritis should engage in low-impact activity to protect their joints. Federal guidelines recommend those not affected by osteoarthritis engage in at least 2.5 hours a week of moderate-intensity activity to reduce the risk for heart disease and many other chronic diseases.

“Our goal was to see what kind of activity would help people remain free of disability,” Dunlop said. “One hour a week is a stepping stone for people who are currently inactive. People can start to work toward that.”

The study is published in the American Journal of Preventive Medicine.