You've trained for months. Don't let nutrition derail your race.

Here's how to fuel before and during any race distance.

The Golden Rule

Nothing new on race day.

Every food, drink, gel, and timing strategy must be tested in training. Race day is not the time to discover that a certain gel makes you nauseous.

Pre-Race Nutrition

Days Before

48-72 hours out:

• Increase carbohydrate intake (especially for marathon)
• Stay well hydrated
• Avoid excessive fiber (reduce GI issues)
• Skip alcohol

What carb loading means:

• 70%+ of calories from carbs
• NOT eating more total calories (just shifting ratios)
• Only necessary for races over 90 minutes

Night Before

Dinner goals:

• Carb-focused (pasta, rice, potatoes)
• Moderate protein
• Low fat and fiber
• Familiar foods only
• Normal portions (don't stuff yourself)

Good options:

• Pasta with marinara sauce
• Rice with grilled chicken
• Baked potato with light toppings
• Bagel with peanut butter

Avoid:

• Spicy foods
• High-fiber vegetables
• Heavy cream sauces
• Excessive portions
• New restaurants or cuisines

Morning Of

Timing: Finish eating 2-4 hours before start.

Target: 200-400 calories, primarily carbohydrates.

Good options:

• Toast or bagel with honey/jam
• Banana
• Oatmeal (made with water, light toppings)
• Energy bar (tested previously)
• White rice with honey

Characteristics:

• Easily digestible
• Low fiber
• Low fat
• Familiar

Pre-Race Hydration

Night before:

• Drink normally (don't over-hydrate)
• Urine should be pale yellow

Morning:

• 16-20 oz in the 2-3 hours before
• Small sips up to 30 minutes before
• Don't gulp large amounts right before start

During-Race Fueling

When Do You Need It?

The reason: Glycogen stores last roughly 90-120 minutes of moderate effort. Beyond that, you need external fuel.

What to Use

Gels:

• Concentrated carbs (20-25g per gel)
• Easy to carry and consume
• May require water
• Practice timing and brand in training

Chews/Blocks:

• Easier on some stomachs
• Require more chewing
• Similar carb content to gels
• Good alternative if gels don't work for you

Sports Drinks:

• Carbs + hydration together
• Easier on stomach
• Lower concentration per serving
• Often available at aid stations

Real Food:

• Works for ultras and some marathoners
• Bananas, oranges, pretzels common
• Requires more digestion
• Psychological appeal for some

How Much

Target: 30-60g carbohydrates per hour for races over 90 minutes.

Practical application:

• 1 gel every 30-45 minutes
• Or 8-12 oz sports drink every 15-20 minutes
• Or combination of both

More isn't better: Excess carbs can cause GI distress. Find your tolerance.

Timing Strategy

For marathon example:

Start early. Don't wait until you feel depleted—absorption takes 15-30 minutes.

Use our Race Fueling Calculator to plan your strategy.

Distance-Specific Strategies

5K

Pre-race focus only.

Fueling during a 5K isn't necessary—it's over before you'd benefit.

Strategy:

• Normal eating day before
• Light pre-race meal 2-3 hours out
• Small carb snack 30-60 min before if desired
• Sip water up to start

10K

Primarily pre-race.

Most runners don't need fuel during a 10K (40-70 minutes).

Strategy:

• Normal eating day before
• Pre-race meal 2-3 hours out
• Water at aid stations if desired
• Maybe sports drink for warm conditions

Half Marathon

Pre-race + some during.

At 90-150 minutes, you're in the zone where fueling helps.

Strategy:

• Moderate carb focus day before
• Pre-race meal 2-4 hours out
• One gel at miles 6-7 (for most runners)
• Second gel at miles 10-11 if needed
• Water at aid stations

Marathon

Full nutrition plan essential.

2:30-5+ hours means glycogen depletion is guaranteed without fueling.

Strategy:

• Carb loading 2-3 days before
• Pre-race meal 3-4 hours out
• Start fueling at mile 4-5
• Continue every 4-5 miles
• 4-5 gels total for most runners
• Consistent hydration throughout

Ultramarathon

Complex nutrition becomes critical.

Multi-hour events require real food, varied nutrition, and careful planning.

Differences from marathon:

• Real food often necessary (stomach rejects gels over hours)
• Fat and protein can be included
• Aid station food becomes important
• More individualized based on duration

Common Mistakes

1. Eating Too Much Morning Of

The problem: Large breakfast = stomach issues mid-race.

The fix: 200-400 calories is enough. Less is often more.

2. New Foods on Race Day

The problem: GI distress from untested foods.

The fix: Every single thing you consume should be tested in training.

3. Starting Fuel Too Late

The problem: Waiting until bonking to take gel.

The fix: Start early (mile 4-5 in marathon). Proactive, not reactive.

4. Gels Without Water

The problem: Concentrated carbs without water = stomach issues.

The fix: Take gels with water, not sports drink.

5. Overthinking Short Races

The problem: Complex fueling for a 5K.

The fix: For races under 60 minutes, just focus on pre-race meal.

6. Under-Hydrating Pre-Race

The problem: Starting dehydrated, then over-drinking during.

The fix: Arrive hydrated. Then sip to thirst during race.

Testing Your Plan

Training Run Protocol

On long runs:

1. Eat same pre-run meal at same timing
2. Practice exact fueling strategy
3. Use same products as race day
4. Note any stomach issues
5. Adjust and retest

What to Track

After training runs:

• What did you eat? When?
• Any GI issues?
• Energy levels throughout?
• What worked? What didn't?

Adapting

If something doesn't work:

• Try different brands
• Adjust timing
• Change amounts
• Try different types (gel vs chews vs drink)

Rule: Minimum 3-4 successful tests before race day.

Race Week Nutrition

Monday-Wednesday

• Normal eating
• Adequate carbs
• Stay hydrated
• Reduce fiber slightly

Thursday-Friday

• Increase carb percentage
• Smaller meals, more frequent
• Very low fiber
• Familiar foods only

Saturday (Eve of Sunday Race)

• Carb-focused dinner
• Moderate portions
• Early (6-7 PM)
• Hydrate well

Sunday (Race Day)

• Pre-race meal as practiced
• No experiments
• Execute your plan

Race nutrition is a trainable skill. Build your plan weeks before the race, test everything in training, and execute with confidence on race day. Your legs have done the training—don't let your stomach let them down.

Create your fueling plan with our Race Fueling Calculator.