I'm sure you don't wear cotton anyway - but NO COTTON!!!! And don't wear new shoes!!
Get to the start early, don't leave it to the last minute. It gets very crowded. Go to the bog more than 10 mins before the off, cos the Q for the portajohn is so long. Thinking of no 2s - I always take loperamide (imodium) to stop wanting a dump half way round.
Don't get carried away in the first few miles - remember, this is your race, follow your training and your race strategy. You'll see loads of peeps going like a bull at a gate, don't follow them. If you set off too fast, you will regret it later. You'll catch up with a lot of em at mile 8 when they can't run any more
If you're following a pace group, be realistic. There are no prizes for bailing out.
Plan your hydration. Be sure to drink plenty.
When the going gets tough - as it will
- do remember 'I have trained for this. I can do this. I will finish. Sod off, left side of brain. I am getting that medal. I am going home with some hardware. I am every bit as good as all these other runners. I am going to do this and nobody's going to stop me' or words to the effect.
Above all -
never give up. Even if you have to cross the line on your hands and knees, you are going home with the hardware.
OK?