During last 24 h before race I avoid foods high in fiber. Race day breakfast is usually white bread with butter and jam or honey. I eat to hunger and don’t count calories. Most of the time race day breakfast is not too big as I eat a lot in days prior so I’m not too hungry and probably the nerves start to kick in as well.
For ironman distance races I aim for 400 kcal/h on the bike. I put all calories in one water bottle and I have plain water in the other bottle. Sponser Competition is quite good as it dissolves well so I can put 1800 kcal in one bottle. That’s 450g of powder and I think that amount of dry powder wouldn’t fit in one 750ml bottle. But when you mix it with water it’s a different story. Just make sure to mix it little by little. I usually mix 100 g with a little bit of water, then add another 100 g… It has gel like structure but it’s fluid enough not to get stuck in the bottle. The bottle with calories stays with me all the time and I replace the other bottle (with water) at aid stations. This is quite simple and works well unless you drop your bottle with calories :-).
I don’t like to run with anything around my waist, so for the run I take 2 gels with caffeine. Sponser gels are quite practical as you don’t have to take all at once and they are 70 g each (almost twice as big as normal gel package). Besides that they fit quite well into the hand. I usually finish them by half way mark and then switch to coke.
That’s the general plan, but I try to be flexible. If I notice the digestion is not going well I may back it off a bit. Also, I may switch to coke earlier if I notice digestion problems. Gels are maltodextrin based which is complex form of sugar. During later stages of the race most of the blood goes into the muscles and there’s not a lot left in your stomach which makes digestion slower. That’s why simpler forms of sugar work better for later stages (ie. coke).
The higher the intensity the slower the digestion, so for shorter races I aim for a bit fewer calories. During half-ironman I aim for around 300 g/h on the bike.
For races in hot weather there’s one more thing to think about, electrolytes. I try to load up on them during race week and include some salt tablets during the race. The actual amount depends on the weather and on subjective feeling. If I feel I might start to cramp I’ll take some more. Sponser products have electrolytes included so I rarely use salt tablets.
This works well for me, so I’ll stick to it. The only thing I’d like to try is a bit more caffeine during the bike. Sponser Activator should do the job, but I still haven’t tried it in a race.