🍌 Triathlon Nutrition Planner

Estimate fueling and hydration needs to support your triathlon from sprint through Ironman distances.

Recommended range for halfIron: 6090 g/h

Mild/temperate (500–750 mL/h)

Total Fuel

450 g carbs

1800 kcal

Fluids & Electrolytes

3900 mL

2340 mg sodium

  • Carb gels/drinks: 18.0 × 25 g servings (adjust for product size)
  • Bottles (500 mL): 7.8 total (mix appropriate sodium per bottle)
  • Pre-race meal: ~140 g carbs 3-4 hours before start
  • Post-race recovery: 18 g protein within 30 minutes

How to Use This Calculator

1

Select race distance & duration

Use expected finish time and triathlon discipline to tailor fueling.

2

Choose carbohydrate target

Pick grams per hour based on intensity and gut tolerance.

3

Define hydration conditions

Estimate sweat rate using climate and personal experience.

4

Review totals & plan intake

Translate grams and milliliters into gels, bottles, and recovery nutrition.

Formula

Total Carbs = (Carbs per hour) × (Duration hours)

Total Fluid = (Fluid mL per hour) × (Duration hours)

Total Sodium = (Sodium mg/L) × (Total Fluid ÷ 1000)

Adjust macros based on race length, gastrointestinal tolerance, and environmental demands. Start fueling early—don’t wait until energy dips.

Triathlon Nutrition Strategy

Balanced fueling prevents bonks and GI distress. Combine carbs (glucose/fructose mix), fluids, and electrolytes tailored to your sweat rate and intensity.

Key Principles

  • Practice race-day nutrition during long bricks to test tolerance.
  • Use multiple transportable carbs (glucose + fructose) to exceed 60 g/h uptake.
  • Match sodium intake to sweat sodium via sweat testing or salty taste.

Race Execution

  • Front-load fluids early on the bike before the run.
  • Carry backup nutrition (gels/chews) in case aid stations fall short.
  • Monitor GI cues; adjust intake if bloating or cramps occur.

Frequently Asked Questions

What carbs should I use?

Mix gels, chews, drink mix, or solid foods. Pair glucose-based products with fructose for higher carb absorption (up to 90 g/h).

How do I know my sweat rate?

Weigh before and after a one-hour workout. Weight loss (kg) ≈ liters lost. Adjust fluid intake to replace 60–80% of losses.

Do I need caffeine?

Caffeine (3–6 mg/kg) can enhance endurance. Test during training to avoid jittery effects on race day.

Should I reduce intake late in the run?

Keep fueling if GI allows. Smaller, more frequent sips or chews help maintain energy in the late stages.

What about special needs bags?

Use them for extra bottles, salt tabs, or personal products during half/full Ironman events.