> Isn't this basically also true of exercise? Running is great for you, but it puts a strain on the cartilage Well, exercise and running are not synonymous. A

> Isn't this basically also true of exercise? Running is great for you, but it puts a strain on the cartilage Well, exercise and running are not synonymous. A lot of people who are very active avoid running for the reasons you mentioned, and don’t require knee replacements.