Marathon Nutrition Guide

Personalized nutrition and hydration strategies for optimal marathon performance.

Runner Profile

Pre-Race Nutrition Plan

Carb-Loading (3 Days Before)

560-840g
of carbs per day
  • Focus on easily digestible carbs (rice, pasta, potatoes)
  • Reduce fiber intake gradually
  • Maintain adequate hydration with electrolytes
  • Moderate protein intake (1.2-1.6g/kg body weight)
  • Limit fat to make room for carbohydrates

Day Before Race

  • Breakfast: Carb-rich breakfast (oatmeal, toast, fruit)
  • Lunch: Moderate-sized meal with plenty of carbs, some protein
  • Dinner: Early, carb-heavy dinner (4-5 hours before bed)
  • Hydration: Drink 500-750ml extra water with electrolytes
  • Evening snack: Small carb-rich snack if hungry
  • Avoid alcohol and minimize caffeine

Pre-Race Breakfast

70-280g
of carbs 2-4 hours before
  • Eat 2-4 hours before race start
  • Keep fat, protein, and fiber low to moderate
  • Sample meals:
    • Oatmeal with banana and honey
    • Bagel with jam and small amount of nut butter
    • White rice with small amount of protein
    • Sports drink + energy/granola bar

Race Morning Timeline

  • 4 hours before: Main pre-race meal
  • 2 hours before: Drink 5-7ml/kg of water or sports drink
  • 60-90 min before: Optional small carb snack (banana, energy bar)
  • 30-60 min before: Sip water as needed
  • 15-30 min before: Optional carb mouth rinse or small energy gel
  • Pre-start: Final hydration sips

During Race Fueling Strategy

Carbohydrate Intake

45-60g per hour
optimal intake
  • Start fueling early (30-45 minutes into the race)
  • Consume carbs at regular intervals (every 15-20 min)
  • Mix carbohydrate sources for better absorption:
    • Energy gels (25-30g carbs per gel)
    • Sports drinks (30-60g carbs per 500ml)
    • Chews/blocks (5-10g carbs per piece)
    • Whole foods (banana, dates, etc. for slower paces)

Hydration Strategy

600-800ml per hour
fluid needs
  • Start race well-hydrated but not overhydrated
  • Drink to thirst, aiming for consistent small amounts
  • Alternate between water and electrolyte drinks
  • Practice drinking while running in training
  • Adjust intake based on temperature:
    • Cool weather: Lower end of range
    • Hot weather: Upper end of range

Electrolytes

  • Consuming 300-600mg sodium per hour is recommended
  • Sources of electrolytes:
    • Sports drinks
    • Electrolyte tablets/capsules
    • Salt packets
    • Electrolyte-enhanced gels
  • Heavy sweaters should aim for the higher end of sodium intake
  • Watch for signs of imbalance: nausea, confusion, muscle cramping

Sample Fueling Plan

For a Sub-4:00 marathon:

  • Start to 1 hour: 1 gel at 30-45 min + water/sports drink at aid stations
  • 1-2 hours: Gel every 30-45 min + 120-180ml fluid every 15-20 min
  • 2+ hours: Continue same pattern, possibly increasing frequency of carbs

Important Notes:

  • PRACTICE YOUR RACE DAY NUTRITION DURING TRAINING!
  • Never try new products or strategies on race day
  • Train your gut by practicing your fueling strategy during long runs
  • Have a backup plan if your primary fueling choice isn't available
  • Adjust based on how you feel during the race

Post-Race Recovery Nutrition

Nutrition FAQs