1) Read the articles on 24hr nutrition, pacing and preparation by Dave Cooper and printed in the Road Runners Club booklets “Training for Ultras”. It will be the best few pounds you can spend.
2) Consideration should be given to the following areas all of which need to be considered if a successful nutritional strategy is to be developed. The overwhelming philosophy should be that you take in what you can assimilate and not try and match what you are using. Only at a very slow walking pace can the human body match intake with expenditure for fluid, energy and electrolytes.
Fluid – required fluid intake for different conditions. Basically drink when thirsty.
Energy – energy requirements at different stages of the race. These will differ depending on whether you are fat adapted or not.
Sodium – how much sodium to take in along with other electrolytes
Buffering/Stomach lining – excess stomach acid during races is an often unthought of factor that can cause nausea and vomiting.
Alertness – caffeine intake should at least equal your normal daily intake.
3) My favourite quote on this subject is this one:
“It’s not how many calories you can consume during an event, it’s how few you can consume without slowing yourself down.
What you want is something small, something that puts just the right amount of calories back in and does not waste your body’s energy trying to digest more than you can actually use.”
Bill Nicolai, American triathlete
Everyone is different. Everyone is unique. You have to try things yourself and discover how your mind and body respond when under prolonged stress. Always write a race report including as much accurate data as possible regarding the nutrition you tried and whether or not it was successful. Only in this way can you develop a sound nutritional strategy that works for YOU.