Free Running Calorie Intake Calculator: How Many Calories Should Runners Eat While Running?

How Many Calories Should You Eat While You Run?

When you run, your body prefers to burn glycogen: a quick fuel source that your body stores in your muscles and liver. Your body also burns some fat, and – under specific circumstances – protein.

Glycogen is your body’s favorite fuel source, but here’s the catch: the supply is limited. 

Depending on your muscle mass and body size, you can only store between 1400-2000 calories of glycogen to burn – that’s about 1-2 hours worth of running. 

What happens when you run out of glycogen? You hit THE WALL.

Aka you bonk. But there’s an easy (and delicious) way to avoid hitting the wall: eat while you run. 

You should aim to replenish 25-35% of calories burned per hour, where most – if not, all – calories come from carbohydrates. 

Free Running Calorie Calculator

Enter your weight and average running pace to get an estimate of how many Calories you should be eating per hour when you run.

NOTE: Make sure to slowly build up over a series of runs to these calorie recommendations to give your GI system time to adjust.  

The best place to start is short, easy effort runs, and increase the amount of calories, intensity, and duration from there.

Example Nutrition Strategy:

A 150 pound runner with an average running pace of 10:00 min/mi would be expending roughly 668 calories/hour. 

To replenish  25%-35% of calories burned, the runner needs to eat between 167-234 calories per hour.

Learn more about using energy gels in training and racing by reading our energy gel guide here.