I think this is pretty much an individual thing. Also depends on the course, the temp/humidity, where the aid stations are, and what they serve. I have to drink alot, so I make sure I don't run out of fluids. I start with a full profile aero drink bottle + 1or2 other to refill.

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�The greater danger for most of us is not that our aim is too high and we miss it, but that it is too low and we reach it.� -Michelangelo

MoodBoost Drink : Mood Support + Energy.

I carry three bottles of Perpetuem (two behind the seats bottles and one aero system) on the bike so I don't rely on aid stations at all. As I dump the liquids from the behind the seat bottles to the aero system I throw away the bottles. Works perfectly.

My first 1/2IM was last year. I put Gatorade in the Jetstream, then had water and Gatorade in my behind-the-seat launcher.
With aid stations every 15 miles, I never emptied the Jetstream, so I never needed to re-fill it from my "back up" Gatorade behind my seat. This year I'll move the water to the down tube. I'll keep Gatorade in the Jetstream, but toss any extra after re-filling at the aid stations. Extra-hot weather will shift me back to the 2003 setup.

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Mr Ed
Triathlete with one horsepower

I'm probably way out on one end of the spectrum here, but I will have my Camelbak filled with ice water, my aerodrink filled with Accelerade/Gatorade, and my behind the saddle bottles filled with Accelerade.

I know it sounds like a lot to carry, and is not ideal for everyone, but all of them are empty by the end of the bike, and it saves you from drinking brown water(like the stuff at Tupper Lake last year. Nasty!)

I love the Camelbak because you can drink in the aerobars and don't have to kill yourself reaching for a bottle nearly so often. I'm planning to use my Camelbak for IMUSA this year, I just have to figure out a way to refill it quickly.

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