Marathon Training Nutrition: The Complete Fueling Guide

You're signed up for your spring marathon. Maybe it's Boston, London, or a local race that's been on your bucket list. You've downloaded a training plan, you've got your shoes dialed in, and you're ready to put in the miles.

But here's what most training plans don't tell you: your nutrition strategy needs to be periodized like your running. If you're also planning outdoor cardio activities as cross-training, you'll need to account for that additional energy expenditure in your fueling strategy.

The same fueling approach that works during base building will leave you bonking during 20-milers. Race week carb loading isn't just eating a bunch of pasta. And if you're not tracking your actual energy expenditure during high-mileage weeks, you're probably under-fueling by 500+ calories per day.

Marathon training is a months-long experiment in energy systems. Get the nutrition right, and you'll feel strong, recover faster, and nail your race. Get it wrong, and you'll drag through workouts, lose muscle, and flame out on race day.

Let's break down exactly how to fuel for every phase of marathon training.

Why Marathon Nutrition Is Different

Running a marathon isn't just "cardio." It's a sustained aerobic effort that depletes glycogen stores, breaks down muscle tissue, generates oxidative stress, and requires precise fueling strategies both during training and on race day.

Here's what makes marathon training nutritionally unique:

High Energy Expenditure

The average runner burns about 100-120 calories per mile depending on body weight and pace. During peak training, you might be running 40-60 miles per week. That's an extra 4,000-7,200 calories burned from running alone, not counting your regular daily activity.

A study in Medicine & Science in Sports & Exercise found that endurance athletes often underestimate their energy needs by 20-30%, which leads to chronic under-fueling and worse performance.

Glycogen Depletion and Repletion

Your body can store about 400-500g of glycogen (roughly 1,600-2,000 calories) in muscles and liver. A 20-mile long run can deplete most of this. If you don't refuel properly between sessions, you're starting workouts with half-empty tanks.

Research in the Journal of Applied Physiology shows that glycogen resynthesis takes 24-48 hours with adequate carbohydrate intake. Miss your carb targets, and you're chronically under-fueled.

Protein Needs Increase

You're not just building cardiovascular fitness — you're also causing muscle damage. Long runs create micro-tears in muscle fibers, trigger inflammation, and increase protein turnover.

Studies on endurance athletes suggest protein needs of 1.2-1.6g per kg of body weight, similar to strength athletes. If you're not hitting these targets, you'll lose muscle mass despite all that training.

GI System Training

Your gut needs to learn how to process carbs while blood is being diverted to working muscles. This is why so many runners experience GI distress during races. They never trained their digestive system to handle intra-run fueling.

Research from the International Journal of Sport Nutrition found that gut training (practicing race nutrition during long runs) reduces GI issues and improves carbohydrate absorption during competition.

Immune System Stress

High training volume temporarily suppresses immune function, especially in the hours after long runs. This "open window" makes you vulnerable to illness if you're not supporting recovery with adequate nutrition.

Marathon training nutrition isn't just about eating enough calories. It's about timing, composition, and periodization to match your training.

TDEE for Endurance Athletes: Calculating Your True Burn

Most TDEE calculators fail endurance athletes. They use generic activity multipliers that don't account for the massive caloric expenditure of marathon training.

Here's how to get it right:

Start With Your Baseline

Calculate your basal metabolic rate (BMR) using the Mifflin-St Jeor equation:

Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5 Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161

This is what you burn just existing. Now add your activity.

Add Non-Running Activity

For daily life (work, walking, general movement), multiply BMR by a sedentary factor of 1.2-1.3. Even if you're active outside of running, it's better to underestimate here and count running separately.

Add Running Expenditure

Use this formula for running calorie burn:

Calories = 0.63 × body weight (lbs) × distance (miles)

This accounts for the mechanical cost of running. It's slightly more accurate than the generic "100 cal/mile" rule because it adjusts for body weight.

Example:

• 150-lb runner
• 10-mile long run
• Burn = 0.63 × 150 × 10 = 945 calories

During a 50-mile week, that's 4,725 extra calories from running alone.

Add Cross-Training and Strength Work

If you're doing supplemental work (cycling, swimming, strength training), add those calories separately. Strength training typically burns 200-400 calories per hour depending on intensity.

Weekly Average TDEE

Your TDEE will fluctuate significantly throughout the week based on training. Calculate a weekly average rather than using a single daily number.

Sample Week for a 150-lb runner:

• Monday: Rest day — BMR × 1.3 = 2,080 cal
• Tuesday: 6 easy miles — 2,080 + (0.63 × 150 × 6) = 2,647 cal
• Wednesday: Strength + 4 miles — 2,080 + 300 + (0.63 × 150 × 4) = 2,758 cal
• Thursday: 8-mile tempo — 2,080 + (0.63 × 150 × 8) = 2,836 cal
• Friday: Rest or cross-train — 2,080 cal
• Saturday: 18-mile long run — 2,080 + (0.63 × 150 × 18) = 3,781 cal
• Sunday: 5 recovery miles — 2,080 + (0.63 × 150 × 5) = 2,552 cal

Weekly total: 18,734 calories Daily average TDEE: 2,676 calories

This is way higher than what a generic "moderately active" multiplier would give you (usually around 2,200-2,400 for this person).

The Tracking Mistake Most Runners Make

They eat the same amount every day. This leads to:

• Over-eating on rest days (creating unnecessary surplus)
• Under-eating on high-volume days (compromising recovery)

Smarter approach: match intake to training load. Eat more on long run days and hard workout days. Eat less on rest days. This keeps your weekly average on target while optimizing fuel availability.

Training Phase Nutrition: Base, Build, Peak, Taper

Marathon training isn't linear, and neither should your nutrition be. Each phase has different energy demands and goals.

Base Building Phase (Weeks 1-8)

Training Focus: Aerobic development, building weekly volume, easy mileage

Nutrition Goals:

• Establish fueling habits
• Support gradual volume increase
• Maintain muscle mass
• Don't gain unnecessary weight

Macro Targets:

• Protein: 1.4-1.6g/kg body weight (muscle preservation)
• Carbs: 4-6g/kg (moderate — you're not running super long yet)
• Fat: Fill remaining calories (0.8-1g/kg minimum for hormone health)

Daily Strategy:

• You don't need aggressive carb loading yet
• Focus on consistency — build the habit of fueling adequately
• Practice post-run nutrition timing
• Experiment with pre-run meals to find what works

Sample Day (150-lb / 68kg runner, 7-mile easy run):

• TDEE: ~2,700 calories
• Protein: 95-110g
• Carbs: 270-410g
• Fat: 60-90g

The lower end of carbs is fine here. Save the high-carb days for later phases.

Build Phase (Weeks 9-14)

Training Focus: Increasing long run distance, adding tempo/threshold work, higher weekly volume

Nutrition Goals:

• Support increased glycogen demands
• Fuel quality workouts
• Practice race-week fueling strategies
• Begin gut training for intra-run nutrition

Macro Targets:

• Protein: 1.4-1.6g/kg (maintain)
• Carbs: 6-8g/kg on long run days, 4-6g/kg on easy days
• Fat: Moderate (0.8-1g/kg)

Daily Strategy:

• Carb cycling begins here: higher carbs on long run days and workout days, moderate on easy/rest days
• Start practicing race nutrition during long runs (more on this later)
• Prioritize carbs in post-long-run meals for glycogen repletion

Sample Long Run Day (16 miles):

• TDEE: ~3,600 calories
• Protein: 95-110g
• Carbs: 410-545g (aggressive refueling)
• Fat: 55-75g

Sample Easy Day (5 miles):

• TDEE: ~2,500 calories
• Protein: 95-110g
• Carbs: 270-410g
• Fat: 70-90g

Notice how carbs and total calories shift with training load, but protein stays consistent.

Peak Phase (Weeks 15-18)

Training Focus: Longest runs (18-22 miles), highest weekly volume, final tune-up race

Nutrition Goals:

• Maximize glycogen storage capacity
• Perfect race nutrition protocol
• Maintain energy despite high training stress
• Avoid illness and overtraining

Macro Targets:

• Protein: 1.4-1.6g/kg (critical for recovery now)
• Carbs: 7-10g/kg on long run days, 5-6g/kg on other days
• Fat: Lower (0.7-0.9g/kg on high-carb days)

Daily Strategy:

• This is when nutrition becomes critical
• Under-fuel here and you'll bonk, get injured, or get sick
• Prioritize sleep and stress management (they affect recovery as much as food)
• Front-load carbs around workouts and long runs

Sample 20-Mile Long Run Day:

• TDEE: ~3,900 calories
• Protein: 95-110g
• Carbs: 475-680g (this is a LOT of carbs — intentional)
• Fat: 50-70g

You need aggressive carb intake to refill glycogen after depleting 2,000+ calories worth during the run.

Taper Phase (Weeks 19-20, Race Week)

Training Focus: Volume reduction, sharpening, race prep

Nutrition Goals:

• Maximize glycogen supercompensation
• Maintain weight (don't gain fat from reduced activity)
• Prime digestive system for race day
• Hydrate and load electrolytes

Macro Targets:

• Protein: 1.2-1.4g/kg (slightly lower, less damage occurring)
• Carbs: Increase to 8-10g/kg in final 3 days (carb loading)
• Fat: Reduce to 0.5-0.7g/kg during carb load (gut comfort)

Daily Strategy:

• First week of taper: Reduce calories slightly to match reduced volume (don't drop carbs too much though)
• Final 3 days: Aggressive carb loading (more detail below)
• Reduce fiber intake slightly in final 2 days (gut comfort)
• Cut out any new or experimental foods

Race Week Protocol (detailed later): This deserves its own section.

Macro Targets by Training Phase: Quick Reference

Here's a cheat sheet for a 150-lb (68kg) runner across phases:

| Phase | Weekly Mileage | Avg TDEE | Protein | Carbs (long run day) | Carbs (easy day) | Fat | |-------|---------------|----------|---------|---------------------|------------------|-----| | Base | 25-35 | 2,500 | 95-110g | 270-410g | 270-340g | 70-90g | | Build | 35-45 | 2,800 | 95-110g | 410-545g | 270-410g | 60-80g | | Peak | 45-55 | 3,000 | 95-110g | 475-680g | 340-410g | 55-75g | | Taper | 25-30 | 2,300-2,800 | 80-95g | 545-680g (final 3 days) | 340-410g | 40-60g |

Adjust proportionally for your body weight.

Daily Fueling Strategy: Timing Meals Around Runs

When you eat matters as much as what you eat. Here's how to structure your day based on when you run.

Morning Runners (5-7 AM)

Pre-Run (30-60 min before):

• Small, easily digestible carb source
• Minimal fat and fiber (they slow digestion)
• Examples: banana + honey, white bread with jam, sports drink

Why: You've been fasting overnight. Liver glycogen is depleted. A small carb hit wakes up your metabolism and provides quick fuel without causing GI distress.

Post-Run (within 30 min):

• Carbs + protein combo
• 3:1 or 4:1 carb-to-protein ratio ideal
• Examples: smoothie with fruit + protein powder, bagel with eggs, oatmeal with protein

Why: Glycogen resynthesis is fastest in the first 30-60 minutes post-exercise when glucose transporters are most active.

Rest of Day:

• Spread remaining carbs and protein across 2-3 meals
• Include vegetables and whole foods for micronutrients
• Don't neglect fat (hormone production, vitamin absorption)

Midday Runners (11 AM - 2 PM)

Pre-Run (2-3 hours before):

• Balanced meal with carbs, moderate protein, low fat
• Examples: rice bowl with chicken, pasta with lean protein, turkey sandwich

Why: You need fuel, but enough time to digest. This meal should carry you through the run.

Post-Run (within 60 min):

• Same as morning runners: carbs + protein
• This becomes your lunch or afternoon snack

Evening:

• Normal dinner, emphasizing protein and vegetables
• Add extra carbs if it was a long run or hard workout

Evening Runners (5-7 PM)

Pre-Run (2-3 hours before):

• Substantial lunch with carbs and protein
• Light afternoon snack 1 hour before (fruit, pretzels, energy bar)

Why: You've had all day to fuel. Top off tanks right before without overdoing it.

Post-Run (within 60 min):

• This is dinner
• Prioritize the same carb + protein ratio
• This is your main refueling meal

Before Bed:

• Optional: casein protein or Greek yogurt (slow-digesting protein supports overnight recovery)

The Universal Rule: Fuel the Work

Regardless of timing, the principle is the same:

1. Before: Provide readily available energy
2. After: Rapidly replenish glycogen and protein
3. Throughout: Meet total daily targets

Long Run Nutrition Protocol

Your long run is the cornerstone of marathon training. It's also the most nutritionally demanding workout of the week.

The Night Before

Goals:

• Top off glycogen stores
• Stay hydrated
• Ensure quality sleep

What to Eat:

• High-carb dinner (not a carb overload, just emphasis)
• Moderate protein
• Low-ish fat (easier to digest)
• Familiar foods only (no experiments)

Examples:

• Pasta with marinara and grilled chicken
• Rice bowl with lean protein and veggies
• Baked potato with turkey and steamed broccoli

Hydration:

• 16-20 oz water with dinner
• Sip water before bed (don't chug)
• Electrolyte drink if it's hot or you're a heavy sweater

Morning Of

Timing: Eat 2-3 hours before the run for larger meals, 30-60 min for smaller ones.

What to Eat:

• Target: 1-4g carbs per kg body weight depending on meal timing
• For a 150-lb runner: 70-270g carbs
• Closer to run = smaller amount, further = larger

Examples:

• 3 hours before: Bagel with peanut butter and banana (90g carbs)
• 2 hours before: Oatmeal with berries and honey (60g carbs)
• 1 hour before: White bread with jam (40g carbs)
• 30 min before: Banana or energy gel (25-30g carbs)

What to Avoid:

• High fiber (bran cereals, beans, cruciferous veggies)
• High fat (heavy breakfast meats, cream sauces)
• Dairy if you're sensitive
• New foods (stick to tested options)

During the Run

When to Start Fueling:

• Runs under 90 minutes: Generally fine with just water
• Runs 90+ minutes: Start fueling at 45-60 minutes

How Much:

• Target: 30-60g carbs per hour for runs over 90 min
• Higher intensity or longer duration: Aim for upper end (60-90g/hour)

What to Use:

• Energy gels (20-25g carbs each)
• Sports drinks (14-20g carbs per 8 oz)
• Chews/blocks (8-10g carbs per piece)
• Real food if tolerated (dates, honey stinger waffles)

Timing Protocol for an 18-Mile Run (~2.5-3 hours):

• Mile 5 (45 min): Gel + water (25g)
• Mile 8 (75 min): Gel + sports drink (40g)
• Mile 11 (105 min): Gel + water (25g)
• Mile 14 (135 min): Gel + sports drink (40g)
• Mile 17 (160 min): Gel if needed (25g)

Total: ~155g carbs during the run

Hydration During:

• General rule: 16-24 oz fluid per hour
• Hot/humid or heavy sweater: Upper end or more
• Use sports drinks for some of this (electrolytes + carbs)
• For more details on optimizing hydration and electrolyte balance for endurance activities, see our complete hydration guide

Pro tip: Practice this exact protocol during training. Race day is not the time to test new gels or fueling strategies.

Immediately After (The Golden Window)

Within 30 minutes of finishing:

• Consume easily digestible carbs + protein
• Target: 50-100g carbs, 15-25g protein
• Liquid is often easier when appetite is suppressed

Examples:

• Recovery shake: banana, protein powder, oats, milk (75g carbs, 25g protein)
• Chocolate milk + bagel (80g carbs, 20g protein)
• Sports drink + protein bar (60g carbs, 20g protein)

This kickstarts glycogen resynthesis and muscle repair.

2-4 Hours After (Full Meal)

Target: Large, carb-focused meal

• 100-150g carbs
• 30-40g protein
• Moderate fat
• Include vegetables for micronutrients

Examples:

• Large burrito bowl with rice, beans, chicken, guac
• Pasta with meat sauce and side salad
• Stir-fry with rice, tofu/chicken, vegetables

Rest of Day

Continue eating normally to hit total daily targets. You burned a massive amount of calories — don't be afraid to eat.

Common mistake: Runners under-eat after long runs because they're tired or nauseous. Force yourself to get in at least the immediate post-run fuel and the 2-hour meal. You can make up the rest throughout the day.

Intra-Run Fueling Guide: What, When, How Much

Let's get specific about race nutrition products and protocols.

Types of Fuel

Energy Gels:

• Pros: Portable, consistent carb dose (20-25g), fast absorption
• Cons: Can cause GI distress, need water to dilute, taste fatigue
• Best for: Most runners, standard choice

Popular options: GU, Maurten, SIS, Huma

Sports Drinks:

• Pros: Hydration + carbs + electrolytes in one
• Cons: Bulky to carry, less carb-dense than gels
• Best for: Aid station fueling, hot races

Popular options: Gatorade Endurance, Maurten, Skratch

Chews/Blocks:

• Pros: More "food-like," easier on some stomachs
• Cons: Requires chewing (harder at race pace), can stick to teeth
• Best for: Runners who hate gels

Popular options: Clif Bloks, GU Chews, Skratch Energy Chews

Real Food:

• Pros: Tastes good, feels more satisfying
• Cons: Slower digestion, less precise carb dosing
• Best for: Ultra-runners, slower marathon paces where digestion is easier

Examples: Dates, bananas, honey stinger waffles, PB&J pieces

Gut Training Protocol

Your gut can be trained to absorb more carbs during exercise. This is crucial because untrained guts can only handle ~30g/hour before causing GI issues.

Weeks 1-4 (Base Phase):

• Practice taking 1 gel during long runs
• Get used to fueling with blood flowing to muscles
• Note any GI response

Weeks 5-10 (Build Phase):

• Increase to 30-45g carbs/hour
• Experiment with different brands/types
• Find what works for your stomach

Weeks 11-16 (Peak Phase):

• Push toward 60g carbs/hour on long runs
• Lock in your exact race day products and timing
• Practice drinking + geling simultaneously

Weeks 17-20 (Taper):

• Final tune-up: execute exact race plan during dress rehearsal run
• No more experiments

Research shows that consistent gut training increases intestinal carbohydrate transporters, allowing better absorption and reducing GI distress.

Caffeine Strategy

Caffeine is a proven ergogenic aid for endurance performance. Studies show 3-6mg/kg body weight improves time to exhaustion and perceived exertion.

For a 150-lb (68kg) runner: 200-400mg caffeine

Sources:

• Caffeinated gels (25-40mg per gel)
• Coffee pre-race (95mg per 8 oz)
• Caffeine pills (100-200mg per pill)

Strategy:

• If you're a regular caffeine user: Maintain normal intake, add a gel with caffeine in final miles
• If you're not: Start with small doses during training to assess tolerance

Timing:

• Pre-race coffee: 1 hour before gun
• Caffeinated gel: Miles 18-20 (when you need a kick)

Warning: Caffeine is a diuretic. Balance with hydration. Don't overdo it (>400mg can cause jitters, GI issues, heart palpitations).

Common Intra-Run Fueling Mistakes

1. Waiting too long to start

• Don't wait until mile 18 when you're already bonking
• Start at mile 5-6, or 45-60 minutes in

2. Irregular timing

• Set a watch alarm every 30-45 minutes
• Consistent fueling prevents blood sugar swings

3. Taking gels without water

• Gels are concentrated — they pull water into your gut
• Always chase with 4-6 oz water

4. Trying new products on race day

• Know exactly what's at aid stations
• Carry your own if needed

5. Under-fueling because "I'm not hungry"

• Hunger is not a reliable signal during hard exercise
• Stick to the plan regardless of appetite

Recovery Nutrition Post-Long Runs

The work isn't done when you stop your watch. Recovery nutrition determines whether you adapt and get stronger or dig yourself into a hole.

The First Hour: Critical Window

What happens physiologically:

• Glycogen stores depleted by 50-80%
• Muscle protein breakdown elevated
• Cortisol (stress hormone) high
• Inflammation response triggered
• Glucose transporters maximally active

Your mission: Provide raw materials for recovery.

Target intake:

• Carbs: 1-1.2g per kg body weight (70-80g for a 150-lb runner)
• Protein: 20-25g high-quality protein
• Fluids: 16-24 oz (water or sports drink)

Why this ratio: Research in the Journal of Applied Physiology shows that glycogen resynthesis is 2-3x faster when carbs and protein are consumed together immediately post-exercise compared to waiting 2 hours.

Easy options:

• Smoothie: banana, protein powder, oats, almond milk, berries
• Chocolate milk (16 oz) + banana
• Recovery drink + bagel with peanut butter

Hours 2-6: Full Refueling

Goal: Continue aggressive carb intake to fully restore glycogen.

Target: Another 100-150g carbs, 30-40g protein, plus normal fat intake.

Meal ideas:

• Breakfast burrito: eggs, potatoes, beans, cheese, salsa
• Pasta with meat sauce, side of garlic bread
• Rice bowl: chicken, avocado, beans, veggies
• Pizza (yes, really — carbs, protein, easy to eat when tired)

Rest of Day: Maintenance and Micronutrients

Focus shifts to:

• Meeting total daily calorie and macro targets
• Anti-inflammatory foods (berries, fatty fish, leafy greens)
• Micronutrients for recovery (vitamin C, zinc, magnesium)
• Hydration (keep sipping water)

Include:

• Colorful vegetables (antioxidants)
• Omega-3 rich foods (salmon, walnuts, chia seeds)
• Tart cherry juice (reduces inflammation and muscle soreness)
• Turmeric, ginger (natural anti-inflammatories)

Supplements Worth Considering

Supported by research:

• Protein powder: Convenient way to hit protein targets
• Creatine: 5g/day improves recovery and may help maintain muscle
• Omega-3s: If not eating fatty fish 2-3x/week
• Vitamin D: If deficient (common in runners, affects bone health and immunity)
• Magnesium: Supports muscle function and sleep

Probably not worth it:

• BCAAs (redundant if eating enough protein)
• Glutamine (limited evidence for runners)
• Excessive antioxidants (may blunt training adaptations)

Sleep: The Most Important Recovery Tool

All the nutrition in the world won't matter if you're sleeping 5 hours a night. Research shows that insufficient sleep:

• Impairs glycogen resynthesis
• Increases injury risk
• Blunts muscle protein synthesis
• Weakens immune function

Target: 7-9 hours per night, 8-10 during peak training weeks.

Race Week Protocol: Carb Loading Done Right

You've heard of carb loading. You might picture endless plates of pasta. But there's actually a science to maximizing glycogen storage without feeling bloated or gaining fat.

The Old Method (Don't Do This)

Depletion method:

• Days 1-3: Very low carb + hard training (deplete glycogen)
• Days 4-7: Very high carb + taper (supercompensate)

Why it sucks:

• Miserable depletion phase
• Risk of injury or illness when glycogen-depleted
• Only marginally better than simpler methods

The Modern Method (Do This)

Simple taper + carb load:

• Reduce training volume (you're tapering anyway)
• Increase carb intake last 3 days
• No depletion phase needed

Research in the International Journal of Sports Medicine shows that tapering alone increases glycogen storage by ~20%, and adding extra carbs pushes it to 30-40% above normal.

Day-by-Day Race Week Protocol

7 Days Out:

• Normal training (short shakeout runs)
• Normal eating
• Get organized: confirm race details, pack gear, plan logistics

6 Days Out:

• Last medium-effort run (3-4 miles with a few strides)
• Normal macros
• Start hydrating aggressively

5 Days Out:

• Easy 3-4 miles or rest
• Normal macros
• Continue hydration

4 Days Out:

• Easy 2-3 miles
• Normal macros
• Pre-race jitters start — manage stress

3 Days Out (Carb Load Begins):

• Easy 2-3 miles or rest
• Increase carbs to 8-10g/kg body weight
• Reduce fat to make room for carbs (not zero, just lower)
• Reduce fiber slightly (easier digestion)
• Focus on simple carbs: white rice, white bread, pasta, potatoes, sports drinks

Sample day (150-lb / 68kg runner):

• Target: 545-680g carbs
• Breakfast: Large stack of pancakes with syrup, banana, orange juice (150g carbs)
• Snack: Pretzels and sports drink (60g carbs)
• Lunch: Large white rice bowl with chicken, low-fiber veggies (120g carbs)
• Snack: Bagel with jam (70g carbs)
• Dinner: Pasta with marinara, bread, light protein (140g carbs)
• Evening: Rice cakes with honey (40g carbs)
• Total: ~580g carbs

2 Days Out:

• Very easy 2 miles or rest
• Continue high carb intake: 8-10g/kg
• Reduce fiber more (gut comfort)
• Stay hydrated with electrolytes
• Avoid alcohol (dehydrating, disrupts sleep)

1 Day Out (Day Before Race):

• Rest or very easy 20-min shakeout with a few strides
• Continue high carbs: 8-10g/kg
• Minimal fiber (no beans, broccoli, high-fiber cereal)
• Familiar foods only (no exotic cuisines)
• Moderate sodium (helps retain water and glycogen)
• Hydrate throughout day, ease up evening (don't wake up to pee all night)

Sample pre-race dinner:

• Pasta with simple sauce (marinara or olive oil)
• White bread
• Small portion lean protein (chicken, fish)
• Light vegetables (nothing gas-producing)
• Skip the salad (fiber, bulk)

Evening:

• Lay out all race gear
• Set 2-3 alarms
• Get to bed early (you probably won't sleep great — that's normal)

Race Morning

3-4 hours before:

• Wake up, use bathroom
• Eat pre-race meal: 2-4g carbs/kg (135-270g for 150-lb runner)
• Examples: bagels with jam and banana, oatmeal with honey and toast, pancakes
• Coffee if that's your routine
• Sip water or sports drink

2 hours before:

• Finish eating
• Continue sipping fluids
• Use bathroom (repeatedly)

1 hour before:

• Head to start line
• Sip sports drink or water
• Use bathroom again

30 min before:

• Light warm-up jog (10 min easy)
• Dynamic stretching
• Last bathroom trip

15 min before:

• Final gel or carb source (25g) if desired
• Small sip of water
• Get in corral

Game time.

Race Day Hour-by-Hour Nutrition Plan

Let's map out exactly what to consume from the moment you wake up until you cross the finish line.

4:30 AM - Wake up

• 16 oz water

4:45 AM - Breakfast

• 2 bagels with jam
• 1 banana
• 16 oz sports drink
• Coffee (if habitual)
• Total: ~150g carbs, 400mg caffeine

5:30 AM - Finish eating

• Sip water until 30 min before start

6:30 AM - Arrive at start

• Use bathroom
• Continue sipping

6:45 AM - Warm-up

• 10-min easy jog
• Dynamic stretches
• Final bathroom

7:00 AM - Final fuel

• 1 energy gel
• Few sips water
• Total: 25g carbs

7:30 AM - Race starts

• Nothing until first fuel stop

8:15 AM - Mile 5-6 (45 min in)

• 1 gel + water at aid station
• Total: 25g carbs

8:45 AM - Mile 9-10 (75 min in)

• 1 gel + sports drink
• Total: 40g carbs

9:15 AM - Mile 13-14 (105 min in)

• 1 gel + water
• Total: 25g carbs

9:45 AM - Mile 17-18 (135 min in)

• 1 caffeinated gel + sports drink
• Total: 40g carbs, 100mg caffeine

10:15 AM - Mile 21-22 (165 min in)

• 1 gel + water (if needed)
• Total: 25g carbs

10:30-11:00 AM - Finish!

• Grab whatever they're handing out (banana, bagel, sports drink)
• Don't worry about hitting perfect macros yet — just get something in

Total race fuel: ~180g carbs, 100mg caffeine

11:30 AM - Post-race meal

• Recovery shake or real food
• Target: 75g carbs, 25g protein

1:00 PM - Full meal

• Big lunch: burger and fries, or burrito, or pasta
• Target: 120g carbs, 40g protein
• Celebrate appropriately (that beer is fine)

Rest of day:

• Eat when hungry
• Keep protein moderate-high
• Stay hydrated
• Enjoy the accomplishment

Common Marathon Nutrition Mistakes

Even experienced runners screw this up. Here's what to avoid:

1. Under-Fueling During Training

The mistake: Eating like you're sedentary while running 50 miles/week.

Why it happens:

• Fear of weight gain
• Not tracking actual expenditure
• Underestimating calorie burn from running

The consequence:

• Chronic fatigue
• Poor workout quality
• Increased injury risk
• Loss of muscle mass
• Compromised immune function

The fix: Track your actual TDEE for one week. Include all running. Eat accordingly.

2. Over-Compensating on Rest Days

The mistake: Eating the same high amount on rest days as on 20-mile run days.

Why it happens:

• Increased appetite from training
• Habit of eating large amounts
• Not adjusting intake to match activity

The consequence:

• Unnecessary fat gain
• Feeling sluggish
• Making race day weight target harder to hit

The fix: Use carb cycling. Eat more on high-volume days, less on rest days.

3. Neglecting Protein

The mistake: Focusing only on carbs and ignoring protein needs.

Why it happens:

• "Runners need carbs" messaging
• Thinking protein is only for strength athletes
• Not prioritizing protein at meals

The consequence:

• Muscle loss despite training
• Slower recovery
• Increased injury risk
• Poor immune function

The fix: Hit 1.4-1.6g/kg body weight every day. Track it.

4. Not Practicing Race Nutrition

The mistake: Planning to "just use what's at the aid stations" without testing it.

Why it happens:

• Laziness
• Not realizing gut needs training
• Thinking "it's just a gel, how bad could it be?"

The consequence:

• GI distress during race
• Bonking because you couldn't tolerate fuel
• DNF or miserable finish

The fix: Practice exact race nutrition during every long run in final 8 weeks. No exceptions.

5. Aggressive Carb Loading Without Reducing Fat

The mistake: Adding tons of carbs in race week but keeping fat intake the same.

Why it happens:

• Not understanding that you need to create calorie space
• Thinking "more is better"

The consequence:

• Massive calorie surplus
• Feeling bloated and heavy
• GI discomfort on race day

The fix: When you increase carbs to 8-10g/kg, reduce fat to 0.5-0.7g/kg. Total calories should increase slightly, but not double.

6. Experimenting on Race Day

The mistake: Trying new gels, foods, or strategies during the race.

Why it happens:

• Panic when they run out of preferred gel
• Aid station has something that looks good
• "Everyone else is doing it"

The consequence:

• GI distress
• Bonking from inconsistent fueling
• Race ruined

The fix: Carry your own nutrition. Know what's at aid stations ahead of time. Stick to the plan.

7. Ignoring Hydration

The mistake: Only drinking at aid stations, or drinking way too much.

Why it happens:

• Not paying attention to thirst
• Fear of dehydration (leading to overdrinking)

The consequence:

• Dehydration: cramping, fatigue, poor performance
• Overhydration: hyponatremia (dangerously low sodium), bloating

The fix: Practice drinking 16-24 oz per hour in training. Adjust for conditions. Use sports drinks (electrolytes) for some of this.

8. Cutting Calories to Lose Weight During Peak Training

The mistake: Trying to hit race weight by creating a deficit during highest-volume weeks.

Why it happens:

• Pressure to be "lighter = faster"
• Wanting to look good in race photos
• Poor timing and planning

The consequence:

• Destroyed workouts
• Injury
• Illness
• Bonking in race

The fix: Hit race weight during base or build phase. Maintain during peak and taper. Don't cut calories when training is hardest.

Maintaining Muscle While Running High Mileage

Marathon training is catabolic. Long runs break down muscle. High cortisol from training stress promotes muscle breakdown. If you're not careful, you'll finish your marathon 10 pounds lighter but weaker and skinny-fat.

Here's how to preserve muscle:

1. Prioritize Protein

Target: 1.4-1.6g/kg body weight, every day.

Distribution: Spread across 3-4 meals (20-40g per meal) rather than one huge serving.

Why: Research shows that distributed protein intake optimizes muscle protein synthesis throughout the day.

Example for 150-lb runner:

• Breakfast: Eggs and toast (25g)
• Lunch: Chicken rice bowl (35g)
• Snack: Greek yogurt (15g)
• Dinner: Salmon with quinoa (35g)
• Total: 110g

2. Strength Train (But Smart)

Frequency: 2x per week during base and build, 1x per week during peak, maintenance during taper.

Focus:

• Compound movements (squats, deadlifts, rows, presses)
• Moderate weight (60-75% 1RM)
• Lower volume (2-3 sets per exercise)
• Don't go to failure (saves recovery capacity for running)

Why: Studies on concurrent training show that moderate strength work improves running economy and preserves muscle without interfering with endurance adaptations.

Sample session (30-40 min):

• Goblet squats: 3×8
• Romanian deadlifts: 3×8
• Push-ups: 3×10
• Rows: 3×8
• Planks: 3×30 sec

Timing: Ideally on easy run days or after runs (not before hard workouts or long runs).

3. Don't Create Too Large a Deficit

Rule: If you're running high mileage, you can't also be in an aggressive cut.

Why: You need calories to:

• Fuel workouts
• Recover adequately
• Preserve muscle
• Maintain hormones

Strategy:

• Base/build phase: Small deficit is okay (250-300 cal/day max)
• Peak phase: Maintenance or small surplus
• Taper: Maintenance

4. Prioritize Recovery

Sleep: 8-10 hours during high-volume weeks.

Stress management: High training stress + high life stress = cortisol overload = muscle breakdown.

Rest days: Take them. They're when adaptation happens.

5. Consider Creatine

Dose: 5g per day (timing doesn't matter).

Why: Creatine supplementation has been shown to:

• Preserve muscle mass during endurance training
• Improve high-intensity workout performance
• Support recovery

Bonus: It's cheap, well-researched, and safe.

6. Post-Run Protein

Get protein within 1-2 hours post-run.

Doesn't need to be immediately (the "anabolic window" is more like 3-4 hours), but don't wait until dinner if you ran in the morning.

Why: Protein intake post-exercise reduces muscle protein breakdown and promotes synthesis.

Using Zolt to Track Marathon Training Nutrition

All of this is useless if you're not actually tracking and adjusting. Marathon training nutrition is complex. Your TDEE swings wildly throughout the week, your needs change across phases, and under-fueling by even 200-300 calories per day can derail your training.

Here's where Zolt helps:

Adaptive TDEE Tracking

Zolt doesn't use generic activity multipliers. It learns your actual TDEE based on:

• Weight trends
• Reported intake
• Activity level

During marathon training, this means:

• Your TDEE updates as your training volume increases
• You get accurate targets even during 50+ mile weeks
• You're not guessing at calorie burn

Daily Macro Adjustments

You can adjust your targets based on training schedule:

• High-carb days for long runs and workouts
• Moderate days for easy runs
• Lower days for rest

This built-in carb cycling optimizes fuel availability without creating unnecessary surplus.

Recovery Tracking

Log how you feel after long runs and hard workouts. Over time, you'll see patterns:

• Am I recovering better when I hit higher carb targets?
• Do I feel stronger with more protein?
• Is my weight trending down too fast (sign of under-fueling)?

Fueling Reminders

Set reminders for:

• Post-run nutrition window
• Pre-long-run meal timing
• Hydration throughout day

Race Week Protocol

Plan your carb load in advance:

• Set higher carb targets for final 3 days
• Track to ensure you're hitting 8-10g/kg
• Monitor weight (expect 2-4 lb increase from glycogen and water — that's good)

Post-Race Transition

After your race, Zolt helps you ease back to normal:

• Reduce calories to match lower activity
• Maintain muscle with protein targets
• Transition to next goal (recovery, maintenance, or next training block)

Download Zolt: App Store

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Marathon training is months of disciplined work. Your nutrition strategy needs to match that discipline. Periodize your macros across training phases. Fuel the work. Practice race nutrition religiously. Track your actual energy expenditure. And on race day, execute the plan you've practiced a dozen times.

Do this right, and you won't just finish your marathon — you'll feel strong doing it.

Now go get after it.