More fun, less run... That's what I now say.

Get the fitness bit sorted and spend time working towards the actual goal of said career. Can only learn so much about flying aircraft when doing reps in the gym where you could be proving every so often that you are fit and spend the rest of the time training practically.

Seems a lot more in your own hands. Other services seem to watch over you all the time, but the RAF seems to say 'we have seen that you can be capable, so heres your opportunity to show that you are capable in the long run'. Besides at Cranwell I saw their Kendo team training. I would love to try something like that than just repeatedly going on a treadmill etc.