If you’re exercising for an hour or less, “the amount of carbohydrates you need are minimal,” he says. If, on the other hand, you’ll be working out for more than two hours, “you may want to increase your carbohydrates to about 60 grams per hour,” the equivalent of about one bar and a gel; or two and a half gels; or a half liter of a sports drink plus a gel packet or some other combination thereof. -Asker Jeukendrup (source: nytimes.com).
The article (Do Sport Bars and Gels Provide the Energy of Sports Drinks?) provides a summary of some recent research comparing carbohydrate utilization from sports drinks to bars and gels. What the researchers found was that the carbohydrates from the gels and the sports bars were being metabolized as quickly and as efficiently as those from the sports drink.
Asker Jeukendrup's blog is worth checking out. Besides sports nutrition research, Asker is an accomplished triathlete. He is director of the Human Performance Lab at the University of Birmingham in England.