Question
I'm 56 and play racquetball two times a week, speed walk 6+ miles at a time, and play volleyball. My knees ache after I play. I ice after activities and have been taking Cellaplex for two months. How do I know if I am damaging my knees?
Answer
It is excellent that you are active. In fact, a New England Journal study showed that people who are active actually do better in terms of their arthritis versus people who are not active. This is counter to what most doctors used to preach 20 years ago. It turns out that exercise limits weight gain - which, coupled with age, is the major risk factor for progression of arthritis and thus further joint damage.
It is always good to listen to your body and take breaks - but the amount of activity that you describe sounds ideal. Typically if your knees hurt more than a day or two after your activity or are swollen - then you are likely overdoing it.