Just wondering is anyone could give me a couple of pointers? I'm currently working on my fitness, in preparation for RAF selection in January.

I just feel like i'm not improving any more. at the begining, i felt a difference almost ever run, now it feel like i'm going backwards. I wouldn't class myself as unfit, i've raced mountain bikes and surfed for 10 years, but i'm not a natural runner, and my upper body strength isn't going to win any prizes

would a change of diet help things? more proteins? more carbs?
most of what i eat once had a face, and i'm worried i'm eating more fats than i should be, and just wieghing myself down

any advice greatly apprieciated