Revealed: The Secret To Carb Loading Before A Race

As per a study, carbohydrate overconsumption can benefit an athlete participating in any high-intensity race continuing for over 90 minutes and above. We already know that Olympic triathlons and above require a triathlete to be working at their anaerobic threshold, and carbohydrates are the most efficient among macros in increasing the VO2 max.

Carb loading does sound like a simple strategy to follow, come race day. However, a bad carb load meal plan and an unscheduled carb loading before a race can hamper your chance of achieving your PR on race day. 

A modern strategy is required to implement carb loading, coupled with tapering. In this blog post, we shall discuss the nuances of carb loading before a race in detail.

Let’s begin.

Related: How To Start Training For A Triathlon

What Is Carb Loading?

carb loading before a race, what is carb loading

In the 1960s, scientists Bergstrom and Hultman discovered that when the glycogen stores in the body get depleted due to physical activity, fatigue sets in. Another thing they found was that when the glycogen was replenished, these stores held even more glycogen.

When the glycogen stores are depleted and not replenished properly, the body resorts towards fatty acids and amino acids, which are not able to sustain optimum levels of VO2 max for highly intensive activities such as half Iron or full Ironman.

Therefore, athletes carb-load before a race to maintain optimum levels of glycogen through increased carbohydrate intake, or the more commonly known term carb loading.

Carb loading is a nutrition cum training strategy coupled with the tapering, in modern endurance sports, which involves, maximizing the glycogen stores through a calculative increase of carbohydrates in the diet, implemented for three to four days before the race day.

So we know what carb loading is, but how does it work?

How Does Carb-Loading Work?

In the present world of endurance sports, like marathons, triathlons, cycling, athletes combine carb-loading with tapering.

Tapering is when an athlete reduces the training volume a few days prior to the race with the goal of improving sharpness during the race.

Carb loading is a nutrition-training strategy as it has a training component also along with the nutritional component.

The normal glycogen levels are in the 100-120 mmol/kg range. Training leads to depletion of glycogen levels and taking proper nutrition leads to replenishment of the same.

During tapering, since the training volume is reduced, this leads to a decrease in the rate of depletion, thus contributing towards carb-loading in a way.

A good carb-loading plan can increase the glycogen stores to as high as 150-200 mmol/kg.

The ideal requirement of carb for carb loading is 5-10 grams/kg of body weight every day for 3-4 days prior to the race day.

Another important thing to be remembered for glycogen depletion is that at those peak performance levels, that is while competing in Olympic events and above, the rate of supply of energy is directly proportional to the rate of depletion of glycogen.

Concurrently, the rate of depletion is again directly related to the number of glycogen levels in the stores. 

Thus, more the number of glycogen levels, more is the rate of energy supply, essential for elite endurance events.

When To Start Carb Loading For Triathlon?

when to start carb loading for triathlon, carb loading calculator

Probably one of the most frequently asked questions about carb loading is should you carb load the night before the race.

Well, the answer lies in preparation and practice. If you have practiced long training sessions during your multi-week training period and during that period, your strategy of carb-loading only one night before has been useful, then the answer is a yes.

But, however, some athletes do complain about upset stomachs on the morning of the race due to carb-loading the night before the race.

Particularly for the day prior to the race, it’s better to have a carb-intensive lunch rather than a carb-loaded dinner so that the digestive system has enough time to prevent any chances of stomach upsets as well as up the glycogen levels also.

Coming to the question of when to start carb loading for triathlon, one should probably dedicate a week to it but a more dedicated carb-loading time should be 3-4 days before race day.

Finally, the carb-loading schedule has to coincide with the tapering schedule, and the last week prior to the race is generally meant for that. 

If your race is on D day, your carb-loading schedule should start at D minus 4 mornings and end at night of D minus 1.

What Should I Eat When Carb-Loading For Triathlon?

carb loading before a race, what to eat a night before the race,

Don’t Fat Load

The only thing to remember is not to confuse “carb loading” with “fat loading”. Overconsumption of fat sources such as butter, salad dressings, the cream does not replenish the glycogen levels, instead will lead to the deposition of fatty acid cells.

The tactic behind carb loading is that you have to eat carbs in a greater amount, but don’t overeat also. Much of the glycogen level depletion will as such be reduced with tapering, which will lead to increased levels of glycogen for the race.

The remainder of the replenishment has to be achieved through carb loading.

You have to be careful with carb loading the right way so that you don’t end up with an upset stomach, or other severe effects such as diarrhea or constipation.

What should you not eat the night before a race?

You should neither consume too many fiber-rich carbs or low fiber carbs the night before a race, nor throughout the carb-loading period. High fiber sources, such as fruits, brown bread can cause bloating and abdominal pain whereas a low fiber diet rich in white flour, white rice can clog your system.

What To Eat The Night Before A Race?

The first thing you should be thinking while having your pre-race day dinner is you shouldn’t wake up the next day with gastrointestinal problems. Therefore, have a meal that is not very rich in a high fiber, like bagels, white rice along with some source of fiber like a small salad plate, which will prevent your system from clogging.

Try and also add a protein source, such as poached eggs, lean fish, or chicken to compensate for the daily protein requirement.

Pizza is also a good option for carb-loading, provided it is consumed without cheese or any other toppings which are high-fat sources. It is only good as long as you are consuming the carb content of it.

Proteins And Beverages During Carb Loading

As you train, your body muscles deplete and they wear out. Our body needs one gram of protein per kg of weight just to maintain muscle mass.

The importance of protein for a triathlete cannot be overstated. During the carb-loading period, every meal rich in carbs should be accompanied by a protein source.

The common sources are egg whites, lean chicken and fish, quinoa, etc. Again, be conscious of the fiber intake and be aware that protein-rich foods are also rich in fiber.

Fluids are another important aspect of nutrition that is often ignored. Juices often compensate for the calorie intake and are low in fiber, so they can be included in the diet.

Avoid alcoholic beverages as they are dehydrating as well as bad sources of carbs. You can always have a beer to celebrate your triumph.

Weight Gain Due To Carb Loading

There will be some weight gain due to carb-loading as the glycogen will contribute to weight gain. however, the accumulated glycogen will be burned during the race and it is not dead weight that cannot be overcome.

Our body accumulates 3 parts of water for everyone part carb intake. Therefore, around 75 percent of the weight gain will be water weight which will be used during a race in the form of useful energy.

Carb Loading Calculator and Meal Plan

Carb loading before a race is a serious step on the road to setting up your PR on race day. Therefore, one needs to calculate and monitor his/her calorie intake.

For ease of calculation and approximation, we will take the daily carbs intake during the carb-loading period to be 7.5 grams per kilogram body weight.

The formula to calculate carb-loading goes 

Carbs required per day in grams = body weight in kilograms X 7.5 grams/kg of bodyweight

Therefore, for a 75kg man, the number of carbs required per day will be 560 grams per day.

This amounts to around 2250 calories just in carbs out of the 3000-4500 calorie requirement recommended for endurance athletes. This means around 60 percent of the calorie intake has to come from carbs.

The meal plan is divided into six meals in total with three of them being the regular meals and the other three being snacks. 

Meal of the DayCarbs Required In Grams  Food OptionsCalories Taken via carb 
Breakfast Plus Snack 1210 grams Wheaties, bagel, orange juice, cream cheese, low-fat milk,Toasted muffins with honey, sports drink840kcal
Lunch Plus Snack 2200 grams Whole grain bread, peanut butter, jelly, fruit yogurt, potato chips baked,Banana smoothie with low-fat milk, banana, and honey cereal bar800kcal
Dinner Plus Snack 3150  grams Chicken breast, rice, broccoli, dinner rolls,
Toasted muffins and jam, canned peaches in syrup

Stated above are the carb and calorie requirements to be met for the particular body weight. The stats will vary for different body weights.

I have given the broad food options for you to explore, you may take the help of any health app to know the calorific value of these foods and adjust the quantity accordingly.


With all this information under your belt now, I am sure you will surely be able to accomplish a great carb-loading strategy that will greatly benefit you in your next triathlon.

The one thing that matters the most while cab loading is a conscious effort and discipline of not going overboard. You need to take carb loading as a part of your training, only then can you achieve the best results.

I urge you to practice carb loading before your long training sessions so that your digestive system is not surprised on the day of the race.

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