Carbo-loading is not like cramming for a test. You’ve seen those guys gorging themselves behind a heaping plate of spaghetti at the traditional pre-marathon pasta dinner. But you can’t just feast on the eve of a race and expect the best results. To properly carbo-load, runners need to understand why it matters and how it works.
In the final week before my race at the White River Marathon, I’m focused on resting, mental preparation, and carbo-loading. Each one of these is essential: Rest, because my muscles need to completely heal from the strain of training so that I’m as fresh and strong as possible. Mental preparation, because endurance sports are at least as much mental as physical, and a positive frame of mind is critical. And carbo-loading, to insure I step up to the starting line with sufficient energy stores to make it all the way to the finish line.
I’m looking forward to the pasta dinner Friday night, but carbo-loading actually begins a few days earlier with a menu that includes a lot of pasta, potatoes, pancakes, bananas and bread.
Before we drive down to Arkansas, I’ll make sure the car’s gas tank is full. That’s the theory behind carbo-loading — carbs provide the fuel to power our muscles over a long haul, so it makes sense to fill up your tank before you start running. Don’t want to run out of gas!
Your body converts carbohydrates to glycogen, which is stored in the muscles and the liver. Glycogen is the most easily accessible form of energy to fuel hard-working muscles. As you run a marathon, glycogen levels in your muscles and liver are depleted, which causes fatigue. As glycogen is depleted, your body is forced to turn fat into energy, which is not as efficient as glycogen. As a result, you slow down. Eventually, your brain will order your muscles to stop working altogether; this is called “hitting the wall” or “bonking.” Your body just shuts down and refuses to exert. This is actually a self-preservation instinct, your brain’s way of ensuring there’s always enough glycogen to keep fueling itself, which is a higher biological priority than winning a race.
So for long-distance running, it’s important to start off with glycogen levels as high as possible, and to replenish them during the race. Today I’ll talk about pre-race fueling, or carbo-loading. Tomorrow, I’ll discuss mid-race fueling.
Two keys to successful carbo-loading are the amount and the timing of carbohydrate intake. You can’t completely fill your muscles with glycogen in just one meal, no matter how much you stuff; the process takes about three days. An endurance runner typically needs about 2.25 grams of carbs daily per pound of body weight (or 5 grams per kilogram of body weight) during training. This amount doubles while carbo-loading three or four days before a race. For a 160-pound runner like me, that means I should consume 365 grams of carbs daily during training. I should consume 730 grams of carbs in the days leading up to Saturday’s marathon.
Believe me, that is no mean feat. You really have to work at it, to consume so many carbs. For example, I could eat 45 potatoes a day. I doubt whether I’ll actually reach that level of carbohydrate intake.
On the other hand, as long as I have a good mid-race fueling strategy, carbo-loading isn’t as critical. I’ll plan dinner menus around carb-heavy meals, eat a lot of bananas for snacks (27g of carbs) and drink some extra Prolong sports drink (58g of carbs per 21-ounce serving). Most of my calories between now and Saturday will be from carbs, with less protein.
A downside to this, I’ll likely gain 2-3 pounds. But there is a silver lining … along with every gram of stored carbohydrate, my body will automatically store an extra 3 grams of water. That means I’ll be well hydrated at the starting line.
No matter how much we carbo-load, even when the tank is full our bodies can only store enough glycogen to last about two hours. Since I’m hoping to finish this weekend’s race in 3 1/2 hours, I know that I’ll run out of fuel midway through the race. That’s why mid-race fueling is so important … and the topic of my next post.
Do you have any suggestions for a high-carb diet? What is your favorite carbo-loading meal?