So, there is data that people who are physically active, including runners, actually have less arthritis than people who don't run. That's one thing. However, there's also data that if you have an injury due to running or something else, and you then do that kind of high intact exercise, you'll actually increase your risk of joint damage and possibly go on to arthritis. So, it really comes down to whether or not you've had an injury and many older adults said, I'm a geriatrician, so I see older adults and certainly arthritis of the knees is one of the most common problems that we see. And in those individuals who already have arthritis, we certainly don't recommend high impact exercise. But you can get high intensity aerobic exercise by doing something like stair climbing or walking up an incline, for example. Or alternatively, you can do weightlifting exercise.