Thanks to everyone who replied for the useful information and advice
My crossfit coach has basically told me everything that has been said here..to just simply eat more to fuel my body for everything I'm doing. I was just looking at the best way to do that. I have a pretty good idea of what to eat though, being nutrition has been a fixation of mine for a few years now.
I may be 15 (almost 16 in October) but I think I have a pretty good idea of proper form and exercises to do thanks to my coaching.
I have been crossfiting since late March and already have seen significant gains. But who hasn't seen huge gains doing crossfit?
During this cross country season my goals will definantly be cross country orientated..trying to get my best 5k time down by a few minutes (best time is 22:43).
My crossfit coach and I are working up a plan so after the season I can train hard crossfit and hopefully in a few years maybe work up to the games! (Haha, in my dreams!)