As an endurance athlete, I'm always experimenting with what/when/how much should I eat before, during, and after exercise. It's nice to see some quantitative data that helps this decision-making process. Here's an interesting article on carbohydrate consumption during exercise that seems to peg the optimum carb ingestion at about 70 - 80 g per hour.
While I typically eat a primal/paleo diet most of the time, I do use Infinit as my carb drink of choice on extended (>1.5 hour) bikes and runs. The nice thing about Infinit is that you can personally adjust the amount of carbs, electrolytes, protein, and even flavor to your own specifications and taste. For me, a person who sweats very little (so needs less salt and electrolytes and even less fluid), this is very important. I can increase the density of my drink mix, while dialing down the amount of flavor so that I can get the right amount of carbs and electrolytes while not drowning in fluids that my body simply won't sweat out (there's nothing like that sloshing sound of extra fluids in your stomach while running).
Using my personal formula, I know that I took in exactly 130g of carbohydrates during my 2 hour bike ride yesterday, for a rate of about 65 per hour. I might try upping this with my next batch of Infinit and see if it works better.
If you're going long in your races this year, it's a good idea to start thinking about nutrition now, practicing it on long rides and runs, dialing it in until on race day there are no surprises and no problems. I credit my dozens of nutritional trial runs last year with seeing me through an Ironman on a stomach that was still reeling from the bout of food poisoning earlier in the week. I don't think I could've finished the race if my nutrition hadn't been spot on.
This week on Philosophy In Action, Dr. Diana Hsieh will be interviewing Nell Stephenson on the subject of "Paleo for the Endurance Athlete". I'll be interested to hear if she has any good info for training (other than eat more yams and bananas!).