I don't understand your point. Both these runners have had scans or whatever showing worn cartlidge in knees and hips. I also know a very good fell runner who's had to finish because of arthritis in his hip, also in his 40s. These are scientific facts and I wouldn't say its illogical to lay the cause at running's door.[/QUOTE]
But its n =1 or 2 science....
You can find none runners who have had hip and knee replacements...