Whether you’re a runner, swimmer, rower, cyclist, triathlete, or whatever, odds are that you know the importance of carbohydrates in an endurance athletes’ diet.
Carbs provide the main source of energy for the body, and are stored within the liver and muscles as glycogen.
Glycogen is the body’s fuel.
Once you run out of glycogen, you hit “the wall”.
Hang around other runners long enough, and eventually you’re going to hear terrible stories of how they hit the wall one mile out from the finish line, or something along those lines.
How can we keep from hitting the wall?
You’ve heard about it before, and whether you have a Turkey trot coming up, or are preparing for your next big marathon, carb loading can significantly improve your performance. Research has actually shown that athletes who carb-load can increase their time to exhaustion by 20%, and decrease the total time it takes to cover a certain distance by 3%.1
So if you could currently cover 10 miles in 70 minutes (a 7min/mi pace) before you hit the wall, now you could cover 12 miles before you hit the wall, and you’d run the first 10 miles in 67.1 minutes.
That could be the difference between winning and losing.
So, how does this work?
Carb-loading saturates the muscles with glycogen. When the muscles’ glycogen stores are topped off, the body can go farther before it runs out of fuel. A car with a full tank always travels farther than the car with a half tank, and the same principle applies to our bodies.
We can top off our ‘tanks’, by eating a diet that’s >65% carbohydrate in the days before the big race. With your average sized adult, this typically ends up being around 3-5g of carbs/pound of bodyweight/day.2
“Give me the details!”
Fine, fine, fine. If you want to prep for your next big event, here’s how to do it:
- Eat a high-carb diet (>65% of calories) 2 weeks before race day. This is 3-5g of carbs/pound of bodyweight/day.
- Begin to scale down your training 2 weeks before race day as well, utilizing short workouts with speed intervals the 10 days before the race.
- Don’t train the day before race day.
“I don’t have that kind of time!”
Welp, that’s fine too, as there’s another shorter method of carb-loading. It’s called rapid loading, and researchers have shown that athletes who do so can attain glycogen levels just as high as people who have been carb-loading for up to 6 days.3
(A word to the wise, however: I would definitely practice this one ahead of time to see how you’re gonna feel afterwards, and if your body can handle it. Yeah, you may have topped off glycogen stores, but if you’re not used to sprints, and you’re so sore you can barely walk on race day, glycogen stores aren’t going to matter much.)
Here’s how to do it:
- The beginning of the day before race day, find a stationary bike or your favorite running loop, and go for 2.5 minutes at very close to your limit. You really want to be pushing it here, but still be able to last the entire 2.5 minutes.
- After the 2.5 minutes, you’re going to spend 30 seconds at an all-out sprint. Give it everything you’ve got, but don’t hurt yourself.
- You’ve now depleted a significant amount of your body’s glycogen stores. As soon as tolerable, begin your carb-loading. You want to eat 5g of carbohydrate/pound of bodyweight the rest of the day.
- So, if you weigh 170 pounds, you want to eat 850g of carbohydrate that day.
Speaking of carbohydrates…
Cereals, pastas, breads, oatmeal, fruits, juices, vegetables, gels, crackers, pretzels, potatoes, spaghettios, raisins, rice, honey, jam, and macaroni are all potential sources of carbohydrates that we can use during our carb loading phase.3
Just in case you were wondering, you know.
On Race Day
Come the day of the event, we want to ingest 140-330g of low fiber CHO 3-5 hours before the start time.1 (pg 133) We can get this by eating a large bagel with 2 tablespoons of apple butter, a chocolate chip Clif bar, and a large banana for breakfast well before the event.
Two hours before start time we also want to drink 2 glasses of water. If we continue to eat more, we want to make sure that we do not eat anything within 60 minutes of the start time in order to avoid any possible negative side effects.4
During the Race
During the competition we want to ingest around 70g/hour of CHO for optimal carb delivery.1 Gatorade, powerbars, gels, bananas, and raisins are all an excellent way of doing this. I’d recommend 3 GU energy packets per hour. They’re super lightweight, taste good, and don’t sit in your stomach.
It’s Over! You Finished!
Immediately after the competition, we want to ingest high glycemic index foods. These are carbohydrate sources that get absorbed into our muscles very rapidly following exercise. We want around 1.2g/kg of body weight of CHO for the first 4 hours after the event. After that we can resume our normal diet.1 Baked potatoes, pretzels, bagels, gatorade, watermelon, and popcorn are all a few high-GI foods.
A Few More Words to the Wise
Different people have different bodies. That may seem simple, but it contains a lot of truth in it. Just because one person can get away chugging Gatorade during a race, it may not mean that you can do it. If you’re going to experiment with any new type of training/nutrition plan, make sure that you’re giving yourself ample time to actuallyexperiment with it before race day.
The last thing you want during a marathon is to find yourself making yet another trip to the porta-potty.
Speaking of that, a lot of carbohydrates contain high amounts of fiber as well. When it’s a day or so before race day, watch out for how much of that stuff you’re eating. Certain cereals, vegetables, fruits, and different types of grains can have a lot more fiber than you think, and by eating them you’re setting yourself up for failure.
- Carb-loading prior to competition can drastically improve your performance
- Eat around 3-5g of carbohydrate/pound of body weight/day in order to carb-load
- Don’t eat high-fiber foods the day before the event
- Eat 140-330g of carbohydrate 3-5 hours before athletic competition
- Ingest 70g/hour of carbohydrate during endurance competitions
- And finally, eat 1.2g of high glycemic-index carbohydrate/kg of body weight for the first 4 hours after the event
And that’s it! Give it a try, and see how your times do!
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1. Sport Nutrition, p. 132-133
3. Nancy Clark, p. 115-116
4. Sports and Exercise Nutrition, p. 259