Thanks for all the replies some good tips here that I'm certainly taking on board.
Fluids wise I'm drinking a 500ml isotonic drink throughout the round, I do quite a lot of walking as we have a recently got a puppy so we'll be increasing the distance we can walk together. I'm working on getting my weight down, but generally have struggled with motivation, but now I've set myself a goal of losing around a stone by the end of this year, playing to my handicap (28) more consistently and getting it down, and entering competitions at my club. If i could play the back 9 to the same standard as the front I would be shooting high 80's to low 90's.