Please, please, please don't just keep on going through your pain until you know what it is, what is causing it, and what you are doing to your joints.

In my 20's I ran and ran and ran, through the pain until I couldn't even walk anymore, thinking I was being strong, and also not wanting to give up the only thing that helped me feel sane in those days. I didn't go to the doc soon enough, because I didn't want to be told to stop.

I really damaged one knee, and it hurts to this day even to hike a little too much. (Thank goodness it works OK for biking when I keep the muscles built up!)