I had arthritis in both knees diagnosed in the fall, went skiing at Christmas with my family, and could barely walk after a little skiing. I gave all my ski equipment away. It let me know that I'll probably need two new knees soon. I've skied in Aspen twice, Jackson Hole, and was a member of a ski club that skied on Killington, VT. Got too old but it surprised me how fast my knees could go bad.