Why is the carbohydrate limit 90g/hr with multiple CHO sources?

Glucose uses SGLT1 intestinal transporter (saturable at approximately 60g/hr). Adding fructose uses GLUT5 transporter, adding 30g/hr capacity. 2:1 glucose:fructose ratio maximizes absorption to 90g/hr and oxidation rate.

When should carbohydrate fueling begin during a race?

For races above 75 minutes: begin fueling at 20-30 minutes to maintain glycogen. For races 45-75 minutes: mouth rinse with CHO solution provides central nervous system benefit. Under 45 minutes: unnecessary for most athletes.

Carbohydrate Fueling During Race Per Hour Calculator

Calculate carbohydrate fueling strategy for endurance races. Capacity: 60 g/hr single CHO source; 90 g/hr multiple transportable CHO (2:1 glucose:fructose). Optimal for events above 75 minutes.

Core Tools

Distance covered in 12 minutes (meters)

🏅 Sports Note: These calculators provide estimates based on population data and validated formulas. Individual results vary by physiology, training level, and testing conditions. Consult a qualified coach or sports scientist for personalized guidance.

How to Use

Enter the values for the scenario you are assessing. Calculate carbohydrate fueling strategy for endurance races. Capacity: 60 g/hr single CHO source; 90 g/hr multiple transportable CHO (2:1 glucose:fructose). Optimal for events above 75 minutes. Use the race carb fueling result to inform your calculation.

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Carbohydrate Fueling During Race Per Hour Calculator

How to Use

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Frequently Asked Questions

Why is the carbohydrate limit 90g/hr with multiple CHO sources?

When should carbohydrate fueling begin during a race?