As someone who suffers from rather severe exertion related GI problems, I've become a big fan of the various products offered by Hammer Nutrition. I use their gel for shorter rides, and move to Sustained Energy for anything over about 2 1/2 hours. It does a great job of keeping me fueled without making me puke. The only problem is....I can't stand the friggen taste!
It didn't bother me at first, but the more I ride, and the more often I use it, the harder and harder it is to make myself gag the stuff down. On my long ride yesterday, I wussed out about half way and stopped at a Starbucks for a slice of pumpkin bread lol. (Strangely enough the pumpkin bread didn't bother my stomach, but the iced chai did.)
So, any suggestions on how to improve the taste...or maybe another non-sugared (no fructose or sucrose) product to use?