There are alot of runners and triathletes out there who are learning how to take in some fuel during events and workouts over an hour and that is great news! The not so good news is that as some of those athletes start going longer than 2-3 hours problems start occurring that didn’t happen before. So what is going on here? Isn’t 1-2 gel packs an hour enough? Do I absolutely have to have an electrolyte supplement? More water? What? Well, the deal is that for events shorter than 3 hours, you can almost fake it on not doing enough. You may feel kind of lousy by the end, by you will survive even though you are running very low on energy, fluid and electrolytes. That is because you should have enough stores of all of those things to make through by doing only minimal amounts of eating and drinking. But…especially after the 3 hour mark…EVERYTHING CHANGES! You just can’t keep up with how much you are losing unless you make a SERIOUS effort to eat and drink more.
While it is true that you are hopefully getting about 50%-60% of your fuel from fat during longer,slower events, you are still blowing through quite a bit of carbohydrate. Most any runner or triathlete will still be using a MINIMUM of 125 grams of carbohydrate an hour. Then, in the case of a Half-Ironman triathlon, the fastest athletes can burn over 200 grams.per.hour! And since we only have about 400-500 grams of carb stored in our muscle tissue and liver, it is easy to see how quickly you will start running out even if you are eating some fuel. Yeah, do that math for a second. ”Let’s see…I take 2 gels an hour or one pack of Clif blocks so that is about 50 grams of carbs I eat in a hour. Okay, well if I am blowing through at least 125 grams, but probably more like 150-175, then I am running an hourly deficit of about 100-125 grams. So by the 3 hour mark, I will have used 300-375 grams of carb and running very very low in fuel and by the 4 hour mark, I will be done!” Yep, all those feelings of being light-headed, sick to the stomach, heavy legged, cranky, crampy, slowing down and feeling like you have been hit by a bus somewhere between the 2 and 3 hour mark does not always have to be the case. Does this ring true to anyone? Is it worth trying more? (Notice here the picture of Mirinda Carfree holding 2 gel flasks full of 100 grams carb each while on her way to running a 2:56 marathon at the end of Ironman Hawaii 2009)