Cheers on trying out for the Ironwoman! I still can't understand how someone could want to run a marathon after 180 km on the bike, so I totally admire you. I am right now training for my first... sprint distance triathlon. But I do cycle a lot.

You definitely will need to eat more and often because when you're on the bike you're catching up on the fuel you couldn't intake from swimming (and it's a pretty comfortable position for eating, especially if you have a bento box!) and fueling up for the run at the same time.

I am currently chewing on leftover Sharkies, "organic energy fruit chews". Basically, it's gel in the shape of gummies, only not bears, sharks. They indeed are fun to eat and I think they taste pretty good (the Berry Blast flavor at least). If you're totally bored you can always have conversations with the sharks as you eat them.

Plain gummy bears are decent too, the difference in nutritional contents probably isn't that big.

Check out different gels. I know there are many I just can't stand (especially the so-called chocolate flavoured) but others that are great (Razz Sorbet) and feel like eating jam by the spoon. On a long ride, your mouth will eventually dry out a bit and it may be easier to eat than anything solid. Bars are probably easier at the beginning of the ride.

(Makes me think I'd like to try maple butter as an energy gel... that would keep me going!)