Something I do that helps before a race or big adventure ride is to start hydrating a couple days before - rehydrate, cramp-ease and non-alcoholic drinks - lots of.
Defnitely helps with in-race cramps and concentration.
Trouble is, when I'm finished, i'm so damn thirsty I head straight for the beers ....... dunno how to fix that one yet
Well buddy I do not want to sound like 'cool medic/peoples (riders) pleaser' but I cannot fault a couple of cold beers after the race knowing that you need to continue the next day.
Beer is filled with carbohydrates and although the 'alcohol and carbonated' part is not good when it comes to hydrating issues and blood glucose levels it is really not going to do anything at all.
However, don't drown yourself in the beer like the spectators but if you have a couple and then a good dinner and continue with a balanced nutritional supplement and something like rehydrate I can't foresee a problem.
We have demined in the Congo - it is very warm and humid and we did just that - we walked kilometres every day sweating profusely while surveying carrying heavy equipment etc and never any issues.
Just as an afterthought. I have been a medic on many events - racing as well and biking but we always get the patients only to hear; 'I did feel a little weird last night or this morning before the race'.....and the medic sits bored out of his mind doing nothing mostly.
Why do you okes not use the event medics? It is a service which you paid for weather you use him or not! So go to the guy and ask him to take you Blood pressure and sugar level! Promise he will not (should not) hold your nuts and make you cough like the school nurse did