How do caloric needs differ in ultramarathons vs. marathons?

Ultra pace is slower (typically 60-75% VO2max), increasing fat oxidation and allowing more mixed-fuel strategies. Total caloric needs are enormous: a 24-hour 100-miler may require 10,000-14,000 kcal total.

What foods work well for ultra events?

Real food tolerance improves at ultra pace: boiled potatoes, rice balls, broth, fruits, sandwiches, and noodles are common. Gels remain useful for key effort sections. High-fat foods are better tolerated at slower paces.

How do you prevent GI issues in ultramarathons?

Practice eating while running in training. Use low-fiber foods during the event. Manage heat (GI function decreases with core temperature rise). Avoid NSAIDs which increase gut permeability. Stay hydrated but do not overdrink.

Ultramarathon Caloric Needs Calculator

Calculate total caloric needs and hourly intake strategy for ultramarathon events (50K to 200+ miles), accounting for the shift to fat oxidation at slower paces and solid food tolerance.

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 total caloric needs and hourly intake strategy for ultramarathon events (50K to 200+ miles), accounting for the shift to fat oxidation at slower paces and solid food tolerance. Use the ultra caloric needs result to inform your calculation.

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Frequently Asked Questions

How do caloric needs differ in ultramarathons vs. marathons?

What foods work well for ultra events?

How do you prevent GI issues in ultramarathons?