I use powerade zero. It has zero sugar but still gives me the electrolytes and flavor I start to crave when I'm riding. A 32 oz bottle is only $.78 at wal-mart. I'll use it in my two 20 oz bottles and top the rest of the way with water. I'll play with the ration depending on the temp outside. Generally on a cooler day it'll be even. on a hot day I'll do a full 20 oz of powerade and the other basically half and half to start with. I can't believe how much sugar you get with gatorade.