New research suggests that just one hour a week of brisk walking can reduce risk of disability in older adults. Northwestern University scientists discovered a minimum amount of brisk walking, as if you are late to an appointment or trying to make a train, provides significant benefit.
“This is less than 10 minutes a day for people to maintain their independence. It’s very doable,” said lead author Dr. Dorothy Dunlop, a professor of preventive medicine at the Feinberg School of Medicine.
“This minimum threshold may motivate inactive older adults to begin their path toward a physically active lifestyle with the wide range of health benefits promoted by physical activity.”
The study appears in the American Journal of Preventive Medicine.
An estimated 14 million older adults in the U.S. have symptomatic knee osteoarthritis, which is the most common form of osteoarthritis. Roughly two in five people with osteoarthritis — most of whom have it in their lower joints — develop disability limitations.
Researchers discovered an hour of weekly moderate-to-vigorous physical activity allowed older adults to maintain their ability to perform daily tasks like getting dressed or cross a street before a traffic light walk signal changed.
The weekly hour of exercise reduced their risk of mobility disability (walking too slowly to safely cross a street or less than one meter per second) by 85 percent. In addition, the exercise helps individuals complete routine tasks 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.
Study investigators analyzed four years of data from more than 1,500 adults in the national Osteoarthritis Initiative from Baltimore, Pittsburgh, Columbus and Pawtucket, Rhode Island.
The adults all had pain, aching or stiffness in lower extremity joints from osteoarthritis but were free of disability when they began the study. Their physical activity was monitored using accelerometers.
“Our goal was to see what kind of activity would help people remain free of disability,” Dunlop said. Federal guidelines recommend older adults with arthritis should participate in low-impact activity.
Although the guidelines recommend 2.5 hours a week of moderately intense activity for reducing the risk for heart disease and many other chronic diseases, this level of activity can be daunting for inactive older adults with lower extremity pain.
“We hope this new public health finding will motivate an intermediate physical activity goal,” Dunlop said. “One hour a week is a stepping stone for people who are currently inactive. People can start to work toward that.”