Race Nutrition Strategy: What to Eat the Day Before, Race Morning, and During the Race

“Fuel right, and you’ll run right and ride right.” Training and equipment determine your ceiling, while your race nutrition strategy determines whether you can reach that ceiling on race day. This article provides a complete race nutrition strategy applicable to marathons, triathlons, and road cycling races.

Energy System Fundamentals

Why Is Fueling So Important?

The main energy sources for endurance sports:

Energy Source	Storage Capacity	Characteristics
Muscle Glycogen	Approx. 1,200–1,800 kcal	Quickly available, limited supply
Liver Glycogen	Approx. 300–400 kcal	Maintains blood sugar, limited supply
Body Fat	Tens of thousands of kcal	Stored in abundance, but slow to utilize
External Carbohydrates	Depends on fueling	The most important factor to manage during a race

Core Issue: Glycogen stores are limited and will be depleted after approximately 2–3 hours of high-intensity exercise. Without replenishment, your pace will drop significantly (hitting “the wall”).

The Day Before the Race

Carbohydrate Loading

The purpose of carbohydrate loading is to maximize glycogen stores in the muscles and liver before race day.

When to use it: Endurance events lasting over 90 minutes (full marathon, 70.3 triathlon, cycling races over 120 km)

Not applicable for: Sprints, 5K–10K road races (existing stores are sufficient)

Carbohydrate Loading Calculation

Consume 10–12 grams of carbohydrates per kilogram of body weight (50–80% more than usual)

Example (70 kg runner):

• Target: 700–840 grams of carbohydrates (approx. 2,800–3,360 kcal from carbohydrates)
• Breakdown: White rice (600 g) provides about 210 g of carbohydrates, pasta (300 g) provides about 220 g of carbohydrates…

Food Choices for the Day Before

Recommended (high-carb, low-fiber):

• White rice, white noodles, pasta
• White bread, bagels
• Bananas, grapes, white rice balls
• Sports drinks, fruit juice

Avoid (high-fiber, may cause gastrointestinal discomfort):

• Whole grains, oatmeal
• Large amounts of vegetables (especially legumes)
• High-fat foods (difficult to digest)
• New foods (don’t try anything new before a race!)

Day-Before Schedule

Time	Meal	Portion
Breakfast	White rice + fried egg + banana	Normal portion
Lunch	Pasta + tomato sauce + chicken breast	Larger portion
Afternoon snack	White bread + jam + sports drink	Light supplement
Dinner	White rice + steamed chicken leg + small amount of vegetables	Largest portion (main loading meal)
Before bed	Banana or a small glass of juice	Light

Race Morning Breakfast

Golden Rules

• Timing: Finish eating 2.5–3 hours before the start
• Portion: Moderate (don’t overeat, avoid indigestion)
• Choice: Familiar foods (don’t try anything new!)

Recommended Breakfast Combinations

Full marathon runners (3 hours before the start):

• 2–3 slices of white toast + jam
• 1–2 bananas
• Plain rice porridge (can add a small amount of egg)
• 500 ml sports drink
• Total: Approx. 60–80 g of carbohydrates

Triathletes (3 hours before the start):

• 1 bowl of white rice
• 2 boiled eggs
• 1 banana
• 1–2 spoons of honey
• Total: Approx. 80–100 g of carbohydrates

Cycling races (2 hours before the start, if the course is shorter):

• 2 slices of white toast + peanut butter
• 1 banana
• 300 ml water

Hydration Management on Race Day

• Drink 500 ml of water immediately after waking up
• Drink water moderately with breakfast (don’t chug too much at once)
• 30 minutes before the start: 250–500 ml of water or electrolytes

Fueling Strategy During the Race

Full Marathon Fueling Plan

Mileage	Fueling Recommendation	Notes
0–15 km	Water only	Conserve digestive system energy, no food
15–20 km	First gel	Glycogen depletion becomes significant
25 km	Second gel + electrolytes	Sodium replenishment becomes important
30 km	Third gel	Critical fueling to prevent hitting the wall
35 km	Supplement based on condition	If feeling good, can take one more gel
Final 7 km	Cola (if available)	Dual boost of caffeine and sugar

Hourly carbohydrate intake target: 60–80 g (roughly one gel every 30 minutes)

Cycling Race Fueling Plan (Example: 4-Hour Race)

Time	Fueling	Amount
Every 20–25 minutes	Water	150–200 ml
Every 45 minutes	Solid food	Banana, energy bar
Every 30 minutes	Carbohydrate calculation	Target 60–80 g/hour

Practical Carbohydrate Content Reference

Food	Portion	Carbohydrate Content
Energy gel	1 packet (30–40 g)	20–25 g
Banana (medium)	1 piece	23–27 g
Energy bar	1 bar	25–45 g
Electrolyte tablet	1 tablet	3–5 g
White rice ball	1 piece	30–40 g

Electrolyte Replenishment

Prolonged sweating causes electrolyte loss, primarily sodium:

• Hourly sodium loss through sweat: 400–1,000 mg (varies by individual)
• Risk of hyponatremia: Consuming too much water without replenishing sodium can lead to hyponatremia (dizziness, nausea)
• Recommendation: Replenish 500–700 mg of sodium per hour (via electrolyte drinks or sodium tablets)

Common Race Nutrition Mistakes

1. Eating too much at breakfast: Leads to gastrointestinal discomfort during the race
2. Trying new foods: Using untested fueling products before and during the race
3. Forgetting to hydrate: Focusing on pace during the race and forgetting to drink at regular intervals
4. Drinking only plain water: Drinking only water without electrolytes during long-distance races
5. Fueling too late: Supplementing only after feeling hungry or fatigued (should be preventive)

Race nutrition strategy is a skill that needs to be repeatedly tested and optimized during training. Starting with your next long training session, follow your race fueling plan to find the combination that works best for you!

Related Reading

• Race Day Nutrition Plan: A Complete Eating Strategy from the Day Before to the Finish Line
• Pre-Race Week Nutrition Supercompensation Strategy: Maximizing Glycogen Stores
• Cycling Race Fueling Strategy: What to Put in Your Pockets and When to Eat
• Running Nutrition Science: Carbohydrate Loading, Race Day Fueling, and Recovery Nutrition