Complete Long Run Nutrition Guide

Nutrition can make or break a long run. Eat too close to your run and you'll have stomach issues. Wait too long to fuel during and you'll bonk. Miss the recovery window and you'll feel it for days. This guide covers everything-timing, amounts, and what actually works.

Part 1: Before Your Long Run

The goal of pre-run nutrition is simple: top off glycogen stores without causing GI distress. How you achieve this depends on the length of your run and your personal tolerance.

Pre-Run Timing Guidelines

What to Eat Before Running

Stick with familiar foods that you know work for you. Common pre-long run choices:

• Oatmeal with banana
• Toast with peanut butter and honey
• Bagel with cream cheese
• Rice with a little salt
• Energy bar or waffles

Avoid high-fat, high-fiber, and high-protein meals close to run time-they take longer to digest and can cause problems mid-run.

The Fasted Long Run Debate

Some runners do long runs fasted to train fat adaptation. This can work for easier, shorter long runs (60-90 minutes), but for harder or longer efforts, the performance cost usually outweighs any metabolic benefits. If you experiment with fasted running, do it on lower-priority training runs, not key sessions.

Part 2: During Your Long Run

The 90-Minute Rule

Your body stores enough glycogen to fuel roughly 90 minutes of moderate-intensity running. This gives us our first guideline:

That doesn't mean you can't fuel on shorter runs-practicing your race-day strategy is valuable even when not strictly necessary. But if you're running easy for an hour, you don't need to carry gels.

Fueling by Duration

As runs extend beyond 90 minutes, carbohydrate intake becomes increasingly important:

These are ranges. Start at the lower end and increase if needed. Some runners absorb carbs better than others-this is partly trainable.

When to Start Fueling

Don't wait until you're depleted. The goal is to supplement your glycogen stores before they run out.

Start fueling 45–60 minutes into your run. Yes, this feels early. But your gut absorbs carbohydrates better when you're not already in an energy crisis.

Carb Absorption Limits

Your body can only process so much:

• Single source (glucose only): ~60g per hour maximum
• Mixed sources (glucose + fructose): Up to 90g per hour
• Practical target: 30-60g per hour for most runners

More isn't better if your gut can't handle it. Start conservative and build up over training.

What to Eat During Runs

The "best" fuel is whatever you can tolerate and will actually eat:

• Gels: Convenient, ~20–25g carbs each. Easy to carry and consume. Popular options: GU Energy Gels, Maurten Gel 100, Spring Energy.
• Chews/gummies: Easier on some stomachs. Require more chewing. Popular options: Clif Bloks, Skratch Chews.
• Sports drink: Provides carbs + fluids together. Maurten 320 and Skratch Labs are runner favorites.
• Real food: Bananas, dates, pretzels work for some runners on slower long runs.

The most important rule: Never try new fueling on race day. Practice everything in training.

Sample Fueling Schedule

A practical schedule for a 2.5-hour long run:

• 0:00 - Start running
• 0:45 - First gel
• 1:15 - Second gel
• 1:45 - Third gel
• 2:15 - Fourth gel (if needed)

Part 3: Hydration and Electrolytes

Fluid Needs

Fluid needs vary dramatically based on temperature, humidity, sweat rate, and individual physiology:

Drink to thirst as a baseline, but learn your sweat rate for hot conditions. You can estimate this by weighing yourself before and after runs (1 lb lost ≈ 16 oz of fluid).

Sodium and Electrolytes

For runs under 2 hours, most runners don't need to worry about sodium. Your body has reserves, and you'll replenish with normal meals afterward.

For longer efforts, especially in heat:

• 2–3 hours: Sports drink usually provides sufficient sodium
• 3+ hours: Consider electrolyte tablets (LMNT, Nuun) or salt capsules (SaltStick)
• Hot conditions: Increase sodium intake regardless of duration

Signs you may need more sodium: muscle cramping, excessive fatigue, craving salty foods during or after runs.

Part 4: After Your Long Run

Post-run nutrition serves two purposes: replenish glycogen stores and provide protein for muscle repair.

The Recovery Window

The "30-minute window" isn't as rigid as once thought, but there are good reasons to eat relatively soon after finishing:

• Glycogen synthesis is elevated immediately post-exercise
• Muscle protein synthesis is primed for repair
• You'll feel better faster if you refuel promptly
• Waiting too long can lead to overeating later

Aim for something within 30-60 minutes. It doesn't need to be a full meal-a recovery shake or snack is fine, followed by a real meal within 2 hours.

Recovery Nutrition Targets

Good recovery options:

• Chocolate milk (classic for a reason)
• Recovery shake with protein and carbs
• Greek yogurt with fruit and granola
• Sandwich with lean protein
• Smoothie with fruit, protein, and milk

Don't Forget Hydration

You've lost fluid and electrolytes. Drink to thirst, and consider adding electrolytes if you were sweating heavily or the run was particularly long or hot.

Part 5: Training Your Gut

Your ability to absorb carbohydrates during exercise is trainable. If you currently struggle with fueling:

• Start with small amounts (15g per hour) and gradually increase
• Practice fueling on every long run, not just hard ones
• Experiment with different products to find what works
• Give your gut time to adapt-improvements happen over weeks, not days

Many runners who think they "can't tolerate" gels simply haven't trained their gut properly. Start small, stay consistent, and your tolerance will improve.

Common Nutrition Mistakes

• Eating too close to the start: Give yourself at least 1-2 hours for digestion.
• Waiting too long to fuel mid-run: Start at 45-60 minutes, not when you're already depleted.
• Taking too much at once: Your gut can only process so much. Spread intake out.
• Neglecting fluids with gels: Most gels need water to digest properly.
• Trying new foods on race day: Test everything in training first.
• Skipping post-run nutrition: Even if you're not hungry, get something in.
• Overcomplicating it: You don't need five different products. Simple and consistent beats elaborate.

Sample Timeline: 2.5-Hour Long Run

Here's a complete timeline for a 2.5-hour long run starting at 7:00 AM:

Adjust based on your personal needs, but the principle remains: prepare before, fuel consistently during, and recover promptly after.

The Bottom Line

Long run nutrition doesn't have to be complicated:

• Before: Eat 2-3 hours ahead, familiar foods, easy to digest
• During: Start fueling at 45-60 min, 30-60g carbs/hour for runs over 90 min
• After: Carbs + protein within 60 minutes, then a real meal
• Always: Practice your race-day strategy in training

The best fueling plan is one you'll actually follow. Start simple, adjust based on experience, and trust your body's feedback.

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