Carb loading is a common practice among long-distance runners and other endurance athletes. It’s a way to get all the energy you need for your big event, particularly if the event involves physical exertion that lasts for hours.
How does it work? The Carb Loading Process involves multiple steps:
Step 1: Start doing heavy, intense exercise a week prior to your event. Raise the intensity of your training and the amount of weight you lift. At the same time, cut back on the amount of carbs you eat. Add more protein and fat to your diet. This will force your body to burn fat instead of carbs.
Step 2: A few days before the race, lower the intensity of your workout and add A LOT of carbs to your diet. You will consume 35 to 50% of your daily calories from carbs in the day or two before your event. This will raise your blood glycogen level, providing a hefty dose of bioavailable energy to use on the day of the big event.
Why does this work? It all comes down to the glycogen in your blood…
Your body only has two sources of energy: glycogen and fat. Fat is harder to burn, so the body uses up the glycogen before turning to stored fat. But your body can only store 390 to 490 calories’ worth of glycogen in your liver and bloodstream–enough to last about 60 to 90 minutes, depending on the intensity of the workout.
But when you carbo-load, you teach your body to store more glycogen. This gives you more available energy on the day of the race, helping you to last beyond the 60 to 90 minutes you’d normally have. The result: better stamina during your endurance event.
Carb Loading Done Right
If you’re planning on carb loading before your big event, here’s what you need to know:
How many carbs? — It is recommended that you consume around 5-7 grams of carbs per 2 lbs of body weight in order to have a healthy body. When carb loading, however, you have to increase your intake to around 9-10 grams per 2 lbs of body weight.
What to eat? — Your goal is NOT to eat nutrient-dense foods that contain a lot of fiber. This will get your digestive system working, causing you to use energy you need for the race. Instead, eat a lot of high-carb, low-fiber foods. Starchy veggies (peas, corn, potatoes) are great to add to your diet, along with low-fiber fruits (like bananas) and refined pastas and breads. This will give you a shot of energy!
How to eat? — You don’t want to have one giant meal of carbs, as this can lead to post-meal fatigue, bloating, and nausea. Instead, try to eat a lot of small carb-heavy meals during the day. This will ensure you get all the carbs you need, but without affecting your stomach.
Here’s how to eat:
48 hours prior to the event, have your last BIG meal. Make sure it does include healthy fats and lean proteins, along with a few complex carbs to provide the minerals and nutrients needed for the race.
24 hours prior to the event, start eating more carbs. Don’t cut the other macros out, but focus on getting more simple carbs (juice, toast, pasta, etc.).
18 hours prior to the event, start shrinking your meals, first eliminating the proteins and fats. The carbs are the most important part of the meal.
2 hours before the event, have your last meal. Keep it small, but make sure it includes plenty of carbs.
It is important to remember carb loading is about increasing your carbohydrate intake and not your calories! Read more about carb loading on the homepage of Mayo Clinic.