Im having some serious gripe with my knees, every time I run I get very bad pain in them when moving and walking. There no pain at all when im riding only running in PE etc. AFter that it hurts for the rest of the day, im presuming cod liver oil tablets and no running for a while?

Take a quick look at this topic;

http://www.southerndownhill.com/forum/index.php/topic,144432.0.html

I've since been told it's because when you grow fast, your bones grow faster than muscle/ligaments and that causes some problems apparently.

Soo i've started physio and have got some stretches to do. Fingers crossed eh