Exercise Won't Up Knee Arthritis Risk

Study Shows Activity Didn't Hurt Healthy Knees of Older Exercisers WebMD 1/31/07 ""There really was no difference between those who exercised and those who didn't in terms of getting knee osteoarthritis," says researcher David T. Felson, MD, MPH...Good workout shoes matched to your activity -- walking, jogging, aerobics, or hiking -- are crucial, he says. "Don't wear them to mow the lawn or go to the mall," he says. Save them for the exercise activity.
And replace them every 3-6 months if you are exercising regularly, he says"

A previous study showed that if you didn't exercise too hard (high impact, high stress) your knees would probably do fine. Your hips on the other hand are another issue - greater chance of getting arthritis here than in the knees. At least for the knees there's a reason to keep only an 8 minute mile and buy new running shoes all the time.

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