Carbohydrate for endurance athletes
Endurance — running, cycling, triathlon, swimming
For training loads around one to three hours a day at moderate to high intensity, the mainstream guidance is roughly 6 to 10 grams of carbohydrate per kilogram of body weight per day. This page uses 6 g/kg — the bottom of that range — because it is the figure most people can actually eat consistently, and a target you miss every day is worse than a slightly conservative one you hit.
Your number
About 420 g of carbohydrate a day.
6 g per kg of body weight. A starting point for a typical training week, not a prescription — a hard week runs higher and a rest day runs lower.
Why this differs from the ordinary recommendation
Carbohydrate is the fuel that runs out. Stored muscle and liver glycogen is finite, and it is the limiter in sustained efforts long before fat stores are.
The requirement scales with body weight and with training volume, not with a percentage of calories — which is why sports nutrition is written in grams per kilogram rather than as a share of the plate.
Under-eating carbohydrate tends to show up as training that feels harder than it should, sessions that fall apart late, and slower recovery between them, rather than as anything dramatic on a single day.
Figures from the American College of Sports Medicine, Academy of Nutrition and Dietetics, and Dietitians of Canada — joint position stand, Nutrition and Athletic Performance (2016). Ranges are given at the conservative end — see the note on each number above.
Where this stops being useful
This is population guidance for a training load, not a plan for a person. Someone training twice a day, or racing, or managing a medical condition that affects blood sugar, needs individual advice from a sports dietitian or their doctor.
Healthy Squirrel gives nutrition estimates, not medical advice.
Track it without doing the arithmetic
Healthy Squirrel has a endurance training mode that sets these targets from your body weight, then fills them in as you log food — alongside every other vitamin and mineral. It's free, there's no account needed to start, and nothing is sold.
Open Healthy Squirrel, then choose Endurance under Training in Settings.
Other guides
Ready to see your full nutrient profile?
Open Healthy Squirrel — it's free