You don’t have to eat ‘regular food’ or ‘solid food’ during a 24 hour time trial. You can if you want but you don’t have to.
And maybe it’s individual. Maybe some riders really do have to take down some regular food for mental reasons. That might be true. Also, maybe if it’s a cold race? I’ve only ever done a 12hr that was just right at freezing & I was OK to drink mostly surgar water through that ride but who knows what a cold 24 would be like.
But if somebody tells you it’s not possible to drink all your nutrition over a 24 hour period of bike riding…well, that’s either just outright ignorance or willful misinformation. It’s no prob during a 24 hour race. In fact, much to the detriment of the field at this race. I’ve never been so whooped by one of the ladies at an ultra event & she drank all her nutrition the whole race. Yikes. Go back to gummy worms, please.
Think temperature is a big factor. My first IM was a hot and windy day, did the whole thing on liquid nutrition and never felt the need for anything solid, in fact I was having to take on water in addition to the energy drink. Second IM was cold and wet, constantly needed to pee (at least it was raining heavily enough to make peeing on the bike fairly straightforward…) and had no desire to keep forcing down energy drink at the rate needed to replace calories so switched to gels and solid foods.
Also if you’re using gels then depends whether you get the ones that are designed to be consumed on their own with no water, or the ones that are more concentrated and need to be washed down with quite a bit of water to avoid GI issues. Have known quite a few people have problems with the latter ones on cooler days where they’re wolfing down the gels but not taking on enough water to go with them.
