Carbo Loading Before Long Runs: Myths and Truths

Any athlete or consistently active person wants to improve their performance when working out, especially when it comes to their strength and endurance. There are many tools used to achieve this: Cross-training, extra workouts, hydration, supplements, etc. But one of the biggest ways that people try to up their game is to adjust their diet. Some may double or triple their lean protein intake to support muscle growth, and others may eat nutrient-rich foods after working out to replenish their body’s stores of vitamins and minerals. But one of the most common nutrition tools used to increase performance is called “carb loading.”

Carb loading is the practice of drastically increasing the amount of carbohydrates that a person intakes before a major athletic event, like a sports game or a marathon. The goal is to pump the body full of extra fuel, i.e., carbs, in the hopes that it will create extra energy stores to be called upon during the game or the race. A lot of athletes experience what they refer to as ‘hitting a wall,’ where they feel a dramatic loss of energy in the middle of the event. It is believed that this is a result of the body running out of stored fuel and therefore running out of energy to support the activity. So, carb loading is used as a tool to prevent this occurrence and increase the athlete’s overall performance.

What Does Carb Loading Do?
So, what is carb loading, and what does it do for the body? When we talk about carb loading, we have to think of the body like an engine. Our body’s engine has a preferred source of fuel: Carbohydrates. Carbohydrates exist in the body in two ways: They are ingested as dietary carbs and are broken down into glucose molecules that travel through the bloodstream. This is the first accessible source of fuel to the body. Any carbs that are not used in the form of glucose get stored away in the body in the form of glycogen. This is the body’s secondary source of fuel.
The issue here lies in the fact that both of these energy stores are extremely limited. Once the glucose and glycogen are depleted, the body has no choice but to use stored fat as fuel. While this may sound ideal to people who want to lose weight, this is not good for athletes. Fat is much harder to break down and requires a lot more oxygen to process. This is what creates that ‘hitting a wall’ effect. The body suddenly has to work much harder to create energy, slowing down the engine.
The goal of carb loading is to drastically increase the level of glucose and glycogen stores in the body before a big event. This way, the body will have access to much more energy and be able to perform better for much longer. So, athletes will often increase their intake of dense carbs in the days before an event while simultaneously reducing their aerobic activity. If they increased their carb intake without decreasing their activity, then these athletes would use up their stored glycogen before the big game or race, making the carb load useless.
If done correctly, carb loading can be a very effective way to increase energy during an athletic event. However, if done incorrectly, carb loading can ultimately do more damage than good. Here are some common myths that people believe about carb loading that can lead to mishaps. Followed by some truths and guidance on how to perform this ritual correctly.

Myths
1) Carb loading can be effective if only performed the night before the event.
This is false. The body needs time to process and store the carbs as glycogen, so an ideal carb load would begin three to six days before the event. If you ingest a heavy meal the night before an event, you will be able to use the resulting blood glucose, but you won’t have had the time to store any useful glycogen. Also, eating particularly heavy meals directly before an athletic event can lead to digestive issues and an ultimate decline in performance.
2) You can carb load with any carbs you want.
Since you are increasing the amount of food you are intaking, you may also be increasing the amount of ingredients and nutrients that might irritate your body. When carb loading, you should eat carbs that are lower in fiber. A sudden increase in fiber often leads to digestional distress and cramping, which is not good to experience right before game day. You should also eat carb-heavy but light-fat foods when carb-loading. Fat increases your satiety. So if you have to eat more food than usual, food that is lower in fat won’t make you feel as full as easily.
3) You have to deplete your glycogen stores before a carb load.
This used to be a common myth in the sports industry. People thought that ‘brand-new’ glycogen stores were the ideal fuel for performance. But recent studies have shown that glycogen stores can be built just as easily and be just as effective if they build upon existing stores. Some athletes even take a few intentional rest days before a carb load just to give their glycogen a head start.

Truths
1) Carb loading is difficult
If you are an athlete, then your diet is already pretty comprehensive. So eating enough food to double or triple your carb intake before a big event can be very difficult. And it can often be difficult mentally to chow down on a bunch of pasta and sit on the couch right before you are expected to perform. But food and rest are exactly what your body needs. Even though it seems backward, this is the time to trust yourself and trust the process. It will pay off in the end.
2) Carb loading should not last more than 7 days
As we mentioned above, you should begin your carb loading process at least three to six days before the big event. However, you shouldn’t go ham on this and try to up your results by starting even earlier. Carb loading should never last longer than seven days. You should maintain a healthy, balanced diet until the beginning of your carb load period. You should focus on high protein and moderate carb and fat intake. If you increase your carb intake too soon, you risk changing your body composition and affecting your athletic performance.
3) Carb loading continues during the race.
Even though you have spent a week eating loads of carbs and building up your glycogen stores, that still may not be enough for a big event like a marathon. That glycogen will be exactly what your body needs when it’s running for hours on end, but you also want to offer it some blood glucose at the same time. You should always plan to eat small, carb-heavy snacks periodically throughout your performance. If you’re running or playing for three hours, you may want to eat a snack every hour. This will give your body an automatic energy boost through the glucose and help reserve the glycogen for later on.