RACE DAY NUTRITION: CALORIES, ELECTROLYTES & WATER
Why Race Day Nutrition Matters - Your race performance is limited far more by fueling than by fitness. Most DNFs, bonks, cramps, and late race blow ups come from:
• Under fueling
• Under hydrating
• Under salting
• Trying something new on race day
Dialing in your nutrition is one of the biggest performance upgrades you can make.
Calories: How Much to Take In - Your body burns far more calories than you can replace — but you must keep the tank topped off.
General Guidelines
• 200–300 calories per hour for most athletes
• 30–90g of carbs per hour, depending on race duration and gut training
• Long course athletes should aim toward the higher end
Carb Targets by Race Type
• Sprint: 30–45g/hr
• Olympic: 45–60g/hr
• 70.3: 60–80g/hr
• Ironman: 70–90g/hr
Best Sources
• Gels
• Chews
• Drink mix
• Bars (early in long races only)
Your gut can be trained just like your muscles — practice your race fueling in training.
Electrolytes: How Much Sodium You Need - Sodium is the key electrolyte for endurance racing.
General Sodium Needs (if you want to know your specific sodium loss - Paul has some testing that will dial this in specifically for you. No Guessing)
• 500–1000 mg sodium per hour for most athletes
• Heavy/salty sweaters: 1000–1500 mg/hr
• Hot/humid races: increase by 20–30%
Signs You Need More Sodium
• Cramping
• Sloshy stomach
• Headache
• Sudden drop in energy
• Feeling “flat” despite calories
Sources
• Electrolyte tablets
• Salt caps
• Sports drink
• High sodium gels
Sodium helps you absorb water — without it, hydration fails.
Water: How Much to Drink - Hydration needs vary by athlete, sweat rate, and temperature.
General Hydration Targets (Paul can help you know your specific sweat loss as well)
• 16–28 oz (475–830 ml) per hour
• Hot races: 28–34 oz/hr
• Cold races: 12–20 oz/hr
The Sweat Rate Test (Do This in Training)
1. Weigh yourself before a 60 minute workout
2. Weigh yourself after
3. Every pound lost = 16 oz of fluid needed per hour
This gives you your personal hydration number.
Putting It All Together (Per Hour Targets)
Component Recommended Range (These vary by individual)
Calories 200–300 kcal
Carbs 30–90g
Sodium 500–1500 mg
Fluids 16–28 oz (more in heat)
These numbers scale with race duration, heat, and your personal sweat rate.
Best Practices in Training - You should never try anything new on race day.
Practice These Weekly
• Fuel every long run/ride exactly like race day
• Use the same gels, drink mix, and timing
• Train your gut to handle 60–90g carbs/hr
• Practice drinking on the bike and during the run
• Test sodium levels in heat and humidity
• Do sweat rate tests in different conditions
Race Simulation Days - At least 2–3 times before your race:
• Eat your race morning breakfast
• Use your race day fueling plan
• Practice transitions + fueling timing
• Test bottle setup, gel placement, and salt strategy
Race Day Execution
Before the Race
• 300–600 calories 2–3 hours before
• 16–20 oz fluids
• 400–600 mg sodium
• 1 gel 10 minutes before the start
During the Race
• Start fueling early
• Sip every 10–15 minutes
• Take sodium consistently
• Adjust fluids based on heat
After the Race
• 20–24 oz fluids per pound lost
• 20–30g protein
• 60–90g carbs
• 500–1000 mg sodium
Coach’s Note
Dialing in race day nutrition is one of the most powerful performance upgrades you can make. If you want help building a personalized plan based on your sweat rate, race distance, and training load, I’m here to help.
Your goals. Your success.
Coach Paul,
PXP Endurance