What is glycogen depletion?

Glycogen depletion occurs when muscle and liver glycogen stores are exhausted. In endurance sports this causes dramatic performance decline known as bonking or hitting the wall.

How long does glycogen last at race pace?

At marathon race pace (roughly 80% VO2max), most athletes deplete glycogen in 90-120 minutes. At half-marathon pace, depletion occurs faster, typically 60-90 minutes.

How can I avoid glycogen depletion?

Pre-exercise carbohydrate loading, consuming 30-90g of carbohydrates per hour during exercise, and training fat oxidation capacity through low-carbohydrate long runs all help delay depletion.

Glycogen Depletion Time Calculator

Estimate time to glycogen depletion at a given exercise intensity. Stored glycogen typically depletes in 60-90 minutes at above 70% VO2max.

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Glycogen Depletion Time Calculator

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Frequently Asked Questions

What is glycogen depletion?

How long does glycogen last at race pace?

How can I avoid glycogen depletion?