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Nutrition by Training Type

How to fuel differently for strength, cardio, HIIT, and endurance training.

📖 The Story​

Three Athletes, Three Different Needs​

Marcus is a powerlifter. His workouts are heavy singles, triples, and sets of five with long rest periods. He read that athletes need lots of carbs, so he carb-loads before every session. But his training isn't glycogen-depleting—he's not doing the volume. He's gained unwanted fat while trying to fuel performance that doesn't need that much fuel.

Elena runs ultra-marathons. She tried intermittent fasting because it "burns fat." On her long training runs, she bonked repeatedly—hitting the wall at mile 15. Her body is efficient at burning fat, but ultra running still requires carbs. She was under-fueling the exact training that needed the most fuel.

Jake does CrossFit—high-intensity workouts mixing lifting and cardio. He eats like a bodybuilder (high protein, moderate carbs) and wonders why he gasses out during metcons. His training is glycolytic—it burns through carbs fast. He needs more fuel than he's providing.

The lesson: Nutritional needs vary dramatically by training type. Strength training, steady-state cardio, HIIT, and endurance events have different fuel requirements. Matching nutrition to training optimizes performance and recovery.

The universal truth: Protein needs are similar across training types (supporting muscle). Carbohydrate needs vary most dramatically based on training intensity and duration.

🚶 The Journey​

Understanding Energy Systems

Your body uses different fuel systems depending on exercise intensity and duration:

Fuel Usage by Training Type:

Training TypePrimary Energy SystemPrimary FuelCarb Dependency
PowerliftingATP-CP (phosphocreatine)Stored ATP, creatineLow
BodybuildingATP-CP + GlycolyticCreatine + glycogenModerate
HIIT/CrossFitGlycolytic + AerobicGlycogen (primary)High
Moderate CardioAerobicFat + glycogenModerate
Long EnduranceAerobicFat + glycogenHigh (for performance)

Key Insight: The harder you work, the more you rely on carbohydrates. Fat burning requires oxygen; at high intensities, you can't supply oxygen fast enough, so carbs become essential.

🧠 The Science​

Energy Systems Deep Dive​

1. ATP-CP System (Phosphocreatine)

  • Duration: 0-10 seconds of maximal effort
  • Fuel: Stored ATP and creatine phosphate in muscles
  • Used for: Heavy lifts, sprints, explosive movements
  • Carb requirement: Minimal (not carb-dependent)
  • Recovery: 2-5 minutes to regenerate

2. Glycolytic System (Anaerobic Glycolysis)

  • Duration: 10 seconds - 2 minutes of intense effort
  • Fuel: Muscle glycogen (stored carbohydrate)
  • Used for: HIIT intervals, CrossFit WODs, repeated high-intensity efforts
  • Carb requirement: High (sole fuel source)
  • Recovery: Minutes to replenish local glycogen

3. Aerobic System (Oxidative)

  • Duration: 2+ minutes, sustained for hours
  • Fuel: Fat + glycogen (ratio depends on intensity)
  • Used for: Running, cycling, swimming, sustained cardio
  • Carb requirement: Moderate to high (higher intensity = more carbs)
  • Capacity: Nearly unlimited (fat stores are huge)

Carbohydrate Requirements by Activity​

Activity TypeDaily Carb NeedPre-Workout Priority
Strength (low volume)3-5 g/kgLow (creatine system)
Strength (high volume)4-6 g/kgModerate
HIIT / CrossFit5-7 g/kgHigh (glycolytic)
Moderate Endurance5-7 g/kgModerate
High-Volume Endurance7-10+ g/kgVery High

For reference: 70 kg person ranges from 210g (low end) to 700g+ (ultra-endurance) daily carbs.

Protein Requirements (Consistent Across Types)​

Protein needs are more consistent across training types:

GoalProtein NeedNotes
General fitness1.4-1.6 g/kgBaseline for active individuals
Muscle building1.6-2.2 g/kgHigher end during building phases
Strength/power1.6-2.0 g/kgSupports recovery and adaptation
Endurance1.2-1.6 g/kgStill important, slightly lower
Fat loss (any type)1.8-2.4 g/kgHigher to preserve muscle

👀 Signs & Signals​

Matching Nutrition to Training Type

SignalPossible MismatchAdjustment
Gassing out during HIIT/CrossFitUnder-carbed for glycolytic trainingIncrease carbs, especially pre-workout
Great energy for lifting but not cardioCarbs sufficient for strength, not enduranceAdd carbs on high-volume or cardio days
Bonking on long runsGlycogen depletedMore carbs before and during
Low energy for strength trainingOverall under-fueledCheck total calories and sleep
Recovery poor after enduranceInsufficient refuelingMore carbs + protein post-workout
Gaining fat despite training hardOver-fueling for training typeMatch carb intake to actual demands
Muscle loss during cardio focusProtein too lowMaintain protein even in endurance phases
Sluggish during morning workoutsGlycogen depleted overnightPre-workout fuel or larger dinner

Weekly Self-Assessment:

After each training session, note:

  1. Training type (strength, cardio, HIIT, etc.)
  2. Energy level (1-10)
  3. Performance vs. expectation
  4. What you ate before

Patterns reveal mismatches between nutrition and training demands.

🎯 Practical Application​

Nutrition by Training Type​

Profile: Heavy compound lifts, low reps, long rest periods (powerlifting, strength-focused programs)

Energy System: Primarily ATP-CP (phosphocreatine)

Nutritional Priorities:

  1. Protein: 1.6-2.0 g/kg daily for recovery and growth
  2. Carbs: Moderate (3-5 g/kg) — not glycogen-depleting
  3. Total Calories: Sufficient to support strength gains
  4. Creatine: 3-5g daily (most effective strength supplement)

Pre-Workout:

  • Not critical if well-fed overall
  • Light snack 1-2 hours before helps
  • Avoid training completely depleted

Post-Workout:

  • 25-40g protein within 2 hours
  • Moderate carbs (not massive amounts needed)
  • Focus on daily totals

Sample Daily Nutrition (80 kg lifter):

  • Protein: 130-160g
  • Carbs: 240-400g
  • Fat: As needed for calories
  • Creatine: 5g daily

Common Mistake: Over-carbing. Strength training doesn't burn as many carbs as you think. Adjust based on actual training volume.

Mixed Training Approach​

What if you do multiple types?

Many people combine strength and cardio, or do programs with varied demands.

Principles:

  1. Identify the dominant demand of each session
  2. Fuel the work — more carbs on high-intensity/volume days
  3. Maintain protein baseline — consistent regardless of session type
  4. Periodize carbs — higher on hard days, lower on easy/rest days

Example: Hybrid Athlete (Lifting + Running)

DayTrainingCarb Level
MondayHeavy squatsModerate
TuesdayEasy runLow-Moderate
WednesdayUpper body + HIITHigh
ThursdayRestLower
FridayDeadliftsModerate
SaturdayLong runHigh
SundayRestLower

Daily carbs might range from 200g (rest) to 450g (long run day) for the same person.

📸 What It Looks Like​

Example Day: Powerlifter (Training at 6 PM)​

7:00 AM - Breakfast:

  • 4 whole eggs + 2 whites
  • 2 slices toast
  • Avocado
  • Coffee
  • Focus: Protein + moderate carbs

12:00 PM - Lunch:

  • 8 oz steak
  • Large baked potato
  • Side salad
  • Focus: Protein + carbs to prepare for training

5:30 PM - Pre-workout:

  • Banana
  • Light, not heavy

6:00-7:30 PM - Heavy squat session

8:00 PM - Dinner:

  • 8 oz chicken breast
  • Rice
  • Vegetables
  • Focus: Protein + carbs for recovery

Daily totals: ~180g protein, ~350g carbs Note: Not crazy high carbs—strength training doesn't require marathon fueling

Example Day: CrossFit Athlete (Training at 5:30 PM)​

7:00 AM - Breakfast:

  • Large bowl oatmeal with banana, honey, berries
  • 2 eggs
  • Orange juice
  • Carb-focused start to fill glycogen

10:00 AM - Snack:

  • Greek yogurt + granola

12:30 PM - Lunch:

  • Large chicken burrito (rice, beans, chicken, vegetables)
  • Substantial carbs + protein

4:30 PM - Pre-workout snack:

  • Rice cakes with honey
  • Quick carbs before glycolytic work

5:30-6:30 PM - CrossFit WOD

7:00 PM - Post-workout:

  • Protein shake + banana (immediate)

8:00 PM - Dinner:

  • Salmon with sweet potato and asparagus
  • Complete recovery meal

Daily totals: ~150g protein, ~450g carbs Note: High carbs support high-intensity glycolytic training

Example Day: Marathon Trainee (Long Run Day - 18 miles)​

Night Before:

  • Pasta with lean meat sauce + bread
  • Pre-loading glycogen

5:30 AM - Pre-run breakfast:

  • Large bowl oatmeal with banana and honey
  • Toast with jam
  • Coffee
  • Carb-heavy, low fat/fiber

7:00-10:00 AM - 18-mile long run

During run (every 45 min):

  • Energy gel or sports drink
  • 30-45g carbs per hour

10:30 AM - Post-run:

  • Protein shake + bagel with peanut butter
  • Large chocolate milk
  • Immediate refueling priority

12:00 PM - Brunch:

  • Eggs, pancakes, fruit, bacon
  • Continue refueling

Daily totals (long run day): ~130g protein, ~550g carbs Note: Long run days require significantly more carbs than rest days

Example Day: Same Marathon Trainee (Easy/Rest Day)​

7:00 AM - Breakfast:

  • 3 eggs
  • 1 slice toast
  • Avocado
  • Lower carbs on rest day

12:00 PM - Lunch:

  • Large salad with grilled chicken
  • Light dressing
  • Protein + vegetables

6:00 PM - Dinner:

  • Fish with roasted vegetables
  • Small portion of rice
  • Lower carbs, focus on protein and nutrients

Daily totals (rest day): ~120g protein, ~200g carbs Note: Carbs reduced on rest days—match fuel to demand

🚀 Getting Started​

4-Week Training-Specific Nutrition Plan​

Week 1: Identify Your Training Type

  • List your weekly training sessions
  • Categorize each: Strength, Hypertrophy, HIIT, Cardio, Endurance
  • Identify the dominant training type
  • Note session durations and intensities

Questions to answer:

  • What type of training do you do most?
  • How many hours per week?
  • What's the intensity distribution?

Week 2: Assess Current Fueling

  • Track food intake for one week
  • Calculate average daily carbs
  • Compare to recommendations for your training type
  • Note energy levels during different session types

Gap analysis:

  • Are you under-carbing for high-intensity work?
  • Over-carbing for strength-only training?
  • Is protein consistent across all days?

Week 3: Adjust to Training Type

  • Set carb targets based on training type guidelines
  • Adjust pre-workout nutrition for session type
  • Match carb intake to training demand (higher on hard days)
  • Track energy and performance changes

Implementation:

  • High-intensity days: Increase carbs
  • Strength-only days: Moderate carbs
  • Rest days: Lower carbs
  • Protein: Consistent daily

Week 4: Refine and Establish Routine

  • Review energy and performance data
  • Fine-tune carb amounts for each training type
  • Establish meal templates for different day types
  • Create pre/post-workout protocols for each session type

Goal: Automatic fueling that matches training without daily calculations.

🔧 Troubleshooting​

Problem 1: "I Gas Out During HIIT/CrossFit"​

Likely cause: Insufficient carbohydrates for glycolytic training

Solutions:

  1. Increase daily carb intake (target 5-7 g/kg)
  2. Carb-focused meal 2-3 hours before training
  3. Add quick carbs 30-60 minutes before
  4. During longer WODs (20+ min), consider sports drink

Problem 2: "Great Energy for Lifting, Terrible for Cardio"​

Likely cause: Carbs sufficient for strength, depleted for cardio

Solutions:

  1. On cardio days, eat more carbs earlier in the day
  2. Ensure pre-cardio snack
  3. For cardio after lifting, have carbs between
  4. Consider training order: cardio when glycogen is fuller

Problem 3: "Gaining Fat Despite Training Hard"​

Likely cause: Over-fueling for actual training demands

Solutions:

  1. Audit actual carb needs for your training type
  2. Strength-only training doesn't require marathon-level carbs
  3. Match calories to expenditure, not perceived effort
  4. Consider body composition goal: if cutting, reduce carbs further

Problem 4: "Bonking on Long Runs Despite Eating Well"​

Likely cause: Not fueling during the activity

Solutions:

  1. For runs over 60-90 minutes, eat during (30-60g carbs/hour)
  2. Practice race nutrition in training (gels, drinks, chews)
  3. Larger carb-focused meal 3-4 hours before
  4. Ensure adequate carbs in days leading up to long run

Problem 5: "Confused—I Do Multiple Training Types"​

Solution approach:

  1. Identify the dominant demand of each session
  2. Fuel each day for that day's training
  3. Keep protein consistent (1.6-2.0 g/kg daily)
  4. Vary carbs: higher on intense/long days, lower on easy/rest days

Example weekly carb variation:

  • Hard HIIT day: 5-6 g/kg carbs
  • Strength day: 4-5 g/kg carbs
  • Easy cardio day: 3-4 g/kg carbs
  • Rest day: 2-3 g/kg carbs

🤖 For Mo​

AI Coach Guidance​

Assessment Questions:

  1. What type of training do you primarily do?
  2. How many hours per week and at what intensities?
  3. Current carbohydrate intake (approximate)?
  4. Any energy issues during specific training types?
  5. Goals (performance, body composition, general fitness)?

Quick Reference by Training Type:

Training TypeCarb RangeKey Focus
Strength (low volume)3-5 g/kgProtein, creatine
Hypertrophy4-6 g/kgProtein timing, surplus/deficit
HIIT/CrossFit5-7 g/kgPre-workout carbs, don't under-fuel
Endurance5-10+ g/kgDuring-workout fuel, periodization

Common Coaching Scenarios:

"I do CrossFit and eat Paleo—is that OK?" → Paleo can work but watch carb intake. CrossFit is glycolytic—it needs carbs. Make sure you're getting enough from Paleo-approved sources (sweet potatoes, fruit). If energy is suffering, consider adding more starches.

"I lift weights and run—how should I eat?" → Base nutrition on your primary goal. Keep protein high (1.6-2.0 g/kg). Vary carbs by the day—higher on running days (especially long runs), moderate on lifting days, lower on rest days. Total weekly carbs will be higher than strength-only.

"I'm doing a bodybuilding cut—how low should carbs go?" → Protein stays high (1.8-2.2 g/kg). Carbs can decrease, but don't go so low that training quality crashes. Try 3-4 g/kg initially, adjust based on energy. Keep some carbs around training for performance.

"I'm training for a marathon—do I need to carb load?" → Traditional carb loading (3 days of high carbs + taper) helps for events over 90 minutes. Practice in training first. Daily carbs should already be high (6-8+ g/kg) during heavy training weeks. Race week: increase to 8-10+ g/kg while reducing volume.

❓ Common Questions​

Do I need different nutrition on rest days?​

Yes and no. Protein stays consistent. Carbs can be lower since you're not burning as much. Total calories can be slightly reduced on rest days, though the difference shouldn't be dramatic.

Can I do keto and high-intensity training?​

It's suboptimal. High-intensity training relies on glycogen. Keto can support low-moderate intensity, but HIIT performance typically suffers on very low carb. If you want low-carb, consider carb-cycling around hard sessions.

How do I know if I'm eating enough carbs for my training?​

Signs of under-carbing: energy crashes during workouts, poor performance, excessive fatigue, struggling with high-intensity work. If you're performing well and recovering, you're likely getting enough.

Does training type affect protein needs much?​

Protein needs are fairly consistent across training types (1.4-2.2 g/kg range). Strength/hypertrophy might be at the higher end; endurance at the lower end. But the difference is smaller than carb variation.

I do hybrid training—should I just average the recommendations?​

Better to match each day to its demand. Strength day = moderate carbs. HIIT day = higher carbs. Long run = highest carbs. Rest day = lower carbs. Average works but isn't optimal.

✅ Quick Reference​

Carb Needs by Training Type​

Training TypeDaily Carbs (g/kg)
Strength (low volume)3-5
Hypertrophy4-6
HIIT / CrossFit5-7
Moderate Endurance5-7
High-Volume Endurance7-10+

Protein Needs (All Types)​

GoalProtein (g/kg)
General fitness1.4-1.6
Muscle building1.6-2.2
Fat loss1.8-2.4
Endurance1.2-1.6

Quick Fueling Guide​

Training TypePre-Workout PriorityDuring WorkoutPost-Workout Priority
StrengthModerateNot neededProtein focus
HypertrophyModerateNot neededProtein + carbs
HIIT/CrossFitHigh (carbs)If 20+ minProtein + carbs
EnduranceHigh (carbs)If 60+ minGlycogen priority

💡 Key Takeaways​

Essential Insights
  • Match carbs to training type — The most variable nutrient
  • Protein needs are more consistent — 1.4-2.2 g/kg across types
  • High-intensity = high carb need — HIIT/CrossFit are glycogen-hungry
  • Strength training needs less fuel than you think — Don't over-carb
  • Endurance needs more fuel than you think — Especially long sessions
  • Mixed training = variable fueling — Adjust daily based on session
  • Don't fear carbs for performance — They fuel hard work
  • Periodize nutrition with training — Hard weeks need more fuel

📚 Sources​

Energy Systems and Fuel Utilization:

  • ACSM Position Stand: Nutrition and Athletic Performance (2016) — Tier A
  • Carbohydrate availability and exercise — Sports Med (2018) — Tier A

Training-Specific Nutrition:

  • ISSN Position Stand: Nutrient Timing — JISSN (2017) — Tier A
  • Nutrition for strength sports — JISSN (2018) — Tier A
  • Endurance athlete nutrition guidelines — JISSN (2019) — Tier A

See the Central Sources Library for full source details.

🔗 Connections to Other Topics​