Reason why I gave up running and replaced it with a stationary bike, all the pounding. Been wearing compression tights at work (landscaping), and this really helped my knees. Too bad I won't live long enough to see a bionic back replacement.: Could really use that!Advice from a old weight lifter. Don't wear out your joints, there is no point to taxing your joints (unless its your job and you are making pro football money). I stay fit now light weights (Im talking lite with high reps), and hiking with pack (wrapped knees). Wish I wouldn't have pushed my body so hard when I was young.