kg
The research supports 36 to 48 hours, so 2 days is the standard.
Carbs per day while loading
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Enter your body weight.
Carb loading calculator
How many grams of carbs to eat per day in the last days before your race, from your body weight and the distance, with what that looks like as food.
How it works
How the numbers are worked out
For events lasting more than about 90 minutes, the sports nutrition position is 10 to 12 g of carbs per kilogram of body weight per day for 36 to 48 hours before the start. The race-morning meal is 1 to 4 g per kilogram, eaten one to four hours before. The calculator multiplies your weight by those ranges.
A Sprint or an Olympic race is under about 90 minutes, so the glycogen already in your muscles is enough. A normal high-carb diet of about 6 to 7 g per kilogram a day does the job and you do not need to load.
Making it work in practice
That is a lot of carbs, so choose foods that are low in fibre and fat: white rice, pasta, bread, bagels, juice, potatoes. Eat often, add drinks and snacks, and leave out anything new. Expect your weight to go up by a kilogram or two, which is water stored with the carbs and is normal.
On the day, move on to race fuel with the triathlon nutrition calculator and the gel calculator. Take the food you trust with you, and add it to your packing list if you are travelling.
Sources
- Burke LM, Hawley JA, Wong SHS, Jeukendrup AE. Carbohydrates for training and competition. Journal of Sports Sciences, 2011;29(Suppl 1):S17-S27.
- Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine joint position statement: nutrition and athletic performance (with the Academy of Nutrition and Dietetics and Dietitians of Canada). Medicine and Science in Sports and Exercise, 2016;48(3):543-568.
- Food carbohydrate values: USDA FoodData Central, SR Legacy, per 100 g scaled to the stated portion weights: cooked white rice 28.2 g, cooked pasta 30.9 g, white bread 49.4 g, plain bagel 52.4 g, orange juice about 10.4 g.
- The 6 to 7 g per kilogram for a normal high-carb day is a typical figure and our estimate.
Questions
How many carbs should I eat before a triathlon?
For a Half or a Full, eat 10 to 12 g of carbs per kilogram of body weight per day for the last 1 to 2 days, then 1 to 4 g per kilogram in the meal one to four hours before the start. A 70 kg athlete eats 700 to 840 g a day while loading.
Do I need to carb load for a Sprint or Olympic triathlon?
No. Races under about 90 minutes are covered by the glycogen you already have. Eat a normal high-carb diet, about 6 to 7 g per kilogram a day, and a carb-rich breakfast a few hours before.
How long should I carb load for?
The guidelines say 36 to 48 hours, so one to two days before the race. A third day is not part of the guidance, but some athletes use it to eat the volume without feeling stuffed.
What should I eat for a carb load?
Low-fibre, low-fat, high-carb foods you know: white rice, pasta, bread, bagels, potatoes, juice and sports drink. Avoid anything new, very high in fibre or very fatty, since you do not want stomach trouble on race day.
Why does my weight go up when I carb load?
Your body stores each gram of carbohydrate with about three grams of water (estimates run from roughly 2.7 to 4 g). A gain of one to two kilograms is common and expected, and it is not a measure of whether the load worked. It comes off during the race as you use the fuel.