Moderate Weekly Exercise Won't Increase Knee Osteoarthritis Risk

Middle-aged adults who engage in up to two and a half hours of moderate physical activity aren't at an increased risk of developing knee osteoarthritis (OA), according to a study supported by the US Centers for Disease Control and Prevention (CDC) and the National Institute of Arthritis, Musculoskeletal, and Skin Diseases (NIAMS).

For their research published online in Arthritis Care & Research, Kamil E. Barbour, PhD, of the CDC’s Arthritis Program, Joanne Jordan, MD, MPH, of the Thurston Arthritis Research Center at the University of North Carolina School of Medicine, and their colleagues analyzed data on 1,522 adults aged 45 years and older that was collected from 1999 to 2010 as part of UNC’s Johnston County Osteoarthritis Project, which also funded the study.

After reviewing the patients’ radiographic results and presence of knee pain and other symptoms related to knee OA, the researchers found that over a median 6.5-year follow-up period, study participants who met the 2008 Department of Health and Human Services (HHS) physical activity guidelines for 150 minutes of walking, conditioning exercises, and household activities per week weren’t at an increased risk of developing knee OA. However, patients who engaged in up to five hours of moderate physical activity each week had a higher risk of developing knee OA compared to inactive study participants, though those associations weren’t statistically significant.

“This study shows that engaging in physical activity at these levels is not going to put you at a greater risk of knee osteoarthritis, (which) held true no matter what a person’s race, sex, or body weight is,” Jordan said in a statement from UNC. “There was absolutely no association between these factors and a person’s (knee OA) risk.”

In light of those results, the researchers recommended that physicians encourage all middle-aged patients to meet the HHS guidelines on moderate weekly levels of physical activity, which Barbour noted are also “a great way to reduce your risk of heart disease, stroke, high blood pressure, diabetes, and other diseases.”