We are in the middle of National Bike Month, and cycling enthusiasts love to talk up the benefits of their favorite activity.

“It’s definitely my longevity drug,” says Brooks Boliek, 65, an avid cyclist of many decades, who used to commute to his office on a bicycle.

A substantial body of evidence supports the health benefits of cycling, everything from strengthening the immune system to boosting the likelihood of living longer. Now, a new study finds people who are in the habit of riding a bike are significantly less likely to have osteoarthritis and experience pain in their knees by age 65, compared to people who don’t bike.

The study, which was funded in part by the National Institutes of Health, and published in the American College of Sports Medicine’s flagship peer-reviewed journal, included about 2,600 men and women, with an average age of 64 years old. They were surveyed about their physical activity over their lifetime. As part of the study, researchers took X-ray images to evaluate signs of arthritis in their knee joints. “Bicyclers were 21% less likely to have X-ray evidence and symptoms of osteoarthritis compared to those who did not have a history of bicycling,” explains study author Dr. Grace Lo of Baylor College of Medicine.