Hypertrophy Training

Evidence-Based Hypertrophy Training Guide

This skill provides a comprehensive overview of scientifically-backed principles for maximum muscle hypertrophy. All information is based on meta-analyses and systematic reviews from 2010 onwards, with emphasis on established findings from key researchers in the field.

> Terminology: For definitions of terms like RIR, RPE, MEV/MAV/MRV, and other abbreviations, see references/glossary.md.

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1. Basic Principles of Hypertrophy

1.1 Mechanical Tension - Primary Driver

Key Finding (Schoenfeld et al., 2017; Wackerhage et al., 2019):

• Mechanical tension is the primary stimulus for molecular mechanisms of hypertrophy
• Acute hormonal responses, metabolic stress, cell swelling ("pump") do not significantly contribute to hypertrophy
• Sarcoplasmic hypertrophy as a standalone phenomenon lacks strong scientific support

1.2 Volume Landmarks (Renaissance Periodization)

For detailed volume recommendations by muscle group, see [volume-landmarks.md](references/volume-landmarks.md).

Quick Reference:

• MEV: 6-10 sets/muscle/week (minimum for growth)
• MAV: 12-20 sets/muscle/week (optimal for most)
• MRV: 20-26+ sets/muscle/week (maximum recoverable)

> Note: Individual variation is ±50%. Start conservatively and adjust based on progress.

1.3 Optimal Per-Session Volume

Maximum per muscle per workout: 6-8 hard sets (Krieger, 2010 [PMID: 20300012]; Schoenfeld et al., 2017 dose-response [PMID: 27433992])

Why 6-8 sets specifically?

• Meta-analyses show diminishing returns above ~10 sets/session
• 6-8 sets = optimal stimulus vs. recovery ratio
• Higher volumes are better split across multiple sessions (increased frequency)

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2. Training Variables

2.1 Training Frequency

Schoenfeld et al. (2016) meta-analysis:

• For hypertrophy: frequency has minimal impact when volume is matched
• For strength: higher frequency has clear benefit
• Practical recommendation: 2x per week per muscle (optimal for most)

2.2 Rep Range

Key Finding (Schoenfeld et al., 2017):

• 5-30+ reps produces comparable hypertrophy when training close to failure
• Higher loads (>75% 1RM) more effective for strength
• Lower loads require more sets to reach complete failure

Practical rep range distribution:

| Rep Range | Use Case | Why | |-----------|----------|-----| | 5-8 | Strength + hypertrophy, compound movements | High mechanical tension, efficient for nervous system | | 8-12 | "Sweet spot" for hypertrophy | Balance between tension and metabolic stress, practical volume | | 12-20 | Isolation, metabolic stress | Lower joint stress, good for pump and technique | | 20-30 | BFR training, high fatigue | Effective only with BFR or for very experienced |

2.3 Proximity to Failure (RIR - Reps in Reserve)

Recommendations:

• 0-3 RIR for most sets
• Training to complete failure not necessary, but effective
• 1-2 RIR = optimal balance of stimulus vs. recovery
• Advanced lifters may need closer proximity to failure

2.4 Tempo / Time Under Tension

Research findings:

• Slow eccentric phase (4s) → greater 1RM improvement and hypertrophy
• Recommendation: 2-8 seconds total rep duration
• Controlled movement > fast or extremely slow

2.5 Rest Periods

• 2-3+ minutes for compound movements (maximize strength)
• 60-90 seconds for isolation (maintain volume)
• Rule: Rest enough to complete prescribed volume

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3. Periodization

3.1 Periodization Models

| Model | Description | Best For | |-------|-------------|----------| | Linear | Progressive load increase, volume decrease | Beginners | | DUP (Daily Undulating) | Different intensities each workout | Intermediate+ | | Block | 3-6 week blocks with different focus | Advanced | | Autoregulation | RPE/RIR-based management | All levels |

Meta-analysis DUP vs LP:

• DUP slightly better for strength (ES = 0.24)
• For hypertrophy: comparable

3.2 Mesocycle Structure

Week 1: Accumulation (lower intensity, higher volume)
Week 2: Accumulation (moderate intensity)
Week 3: Accumulation (higher intensity)
Week 4: Intensification (lower volume, higher loads)
Week 5: Deload (50% volume, 60-70% intensity)

3.3 Deload Protocols

For detailed deload protocols see [periodization.md](references/periodization.md#deload-protocols).

Quick Overview:

• Volume deload: 50% volume, full intensity
• Frequency: Every 4-6 weeks

When to deload:

• Systematically per plan
• With accumulating fatigue
• With stagnation 2+ weeks

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4. Exercises and Exercise Selection

4.1 Lengthened Partials (Milo Wolf Research)

Key Finding (Wolf et al., 2023 [DOI: 10.47206/ijsc.v3i1.182]; Kassiano et al., 2023 [PMID: 37015016]):

• Training at stretched position may provide additional hypertrophic stimulus
• Lengthened partials = bottom 50-70% ROM
• Practical suggestion: Consider including lengthened partial training for some exercises. The optimal proportion is not yet established—current research compares full ROM vs partial ROM, not optimal ratios for mixed programming.

Application examples:

| Muscle | Exercises Emphasizing Stretch | |--------|-------------------------------| | Biceps | Preacher curl (bottom half), incline curl | | Triceps | Overhead extension, skull crushers | | Chest | DB fly (stop before peak), cable crossover low | | Back | Pullovers, seated row with stretch emphasis | | Quads | Leg extension (bottom half), sissy squat | | Hamstrings | Seated leg curl (better than lying), RDL | | Calves | Standing calf raise - deep stretch |

4.2 Stimulus-to-Fatigue Ratio (SFR)

High SFR exercises (prefer):

• Machine exercises with good resistance curve
• Cable exercises
• Exercises at stretched position

Low SFR exercises (limit):

• Heavy deadlifts (high systemic fatigue)
• Barbell rows (spinal erector fatigue)
• Leg press with extreme ROM

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5. Nutrition for Hypertrophy

For complete nutritional protocols see [nutrition.md](references/nutrition.md).

Quick Overview

Protein: 1.6-2.2 g/kg body weight daily Caloric surplus: +200-500 kcal (depending on training status) Distribution: 4-6 protein doses daily, 0.4-0.55 g/kg per dose Pre-sleep: Casein or blended protein (30-40g)

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6. Supplementation

For complete tier-based overview see [supplements.md](references/supplements.md).

Quick Overview

Tier 1 (Recommended): Creatine 3-5g/day, Caffeine 3-6mg/kg, Protein as needed Tier 2 (Consider): Beta-alanine, Citrulline, Vitamin D (if deficient) Not Recommended: Turkesterone, Ecdysterone, most "testosterone boosters"

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7. Recovery

7.1 Sleep

Recommendation: 7-9 hours of quality sleep

| Factor | Impact on Hypertrophy | |--------|----------------------| | Important: Individual response to training varies significantly (up to ±50% in hypertrophy outcomes). The volume landmarks, rep ranges, and other recommendations in this guide represent averages. Track your own progress and adjust accordingly.

Distinguishing Factors

| Factor | High Responders | |--------|-----------------| | Ribosomal biogenesis | Higher | | Satellite cells | Greater proliferation | | Androgen receptors | Higher content | | IGF-1 expression | Elevated |

Strategies for Low Responders

• Increase frequency (3-4x/week per muscle)
• Higher volume (20-30 sets/muscle/week)
• Vary stimuli (different rep ranges, exercises)
• Optimize recovery (protein 2.0+ g/kg, sleep 8+h)
• Patience - progress is slower but still possible

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Reference Files

For detailed information see files in references/:

When to Use Which File

| Situation | Read File | |-----------|-----------| | Creating training plan | programs.md → periodization.md → exercises.md | | Stagnation / plateau | periodization.md (deload) → techniques.md | | Exercise selection for muscle group | exercises.md | | Nutrition / macro questions | nutrition.md | | Supplement evaluation | supplements.md | | Recovery / fatigue / overtraining | recovery.md | | Understanding why something works | mechanisms.md | | Female-specific questions | female-training.md | | Age-specific training (youth, masters, seniors) | age-specific-training.md | | Injury / pain | injury-prevention.md → exercises.md (substitutions) | | Progress tracking | progress-tracking.md | | Motivation / adherence / mental strategies | psychology.md | | Logging / tracking workouts | sample-logs.md → progress-tracking.md |

Troubleshooting Decision Tree

Problem?
├── Not stagnating, but want to optimize
│   └── Read: periodization.md → techniques.md
├── Strength stagnation
│   └── Read: periodization.md (deload) → programs.md
├── Hypertrophy stagnation
│   └── Read: mechanisms.md → exercises.md (lengthened partials)
├── Fatigue / poor recovery
│   └── Read: recovery.md → nutrition.md
├── Injury / pain
│   └── Read: injury-prevention.md → exercises.md (substitutions)
├── Nutrition questions
│   └── Read: nutrition.md → supplements.md
├── Female-specific questions
│   └── Read: female-training.md
├── Age-specific questions (youth, masters, seniors)
│   └── Read: age-specific-training.md
├── Progress tracking
│   └── Read: progress-tracking.md
├── Cardio / conditioning questions
│   └── Read: cardio-interference.md → recovery.md
└── Motivation / adherence / mental blocks
    └── Read: psychology.md

Reference Files

• mechanisms.md - Hypertrophy mechanisms (mTOR, MPS, satellite cells)
• muscle-imbalances.md - Bilateral asymmetries, postural issues, correction protocols
• nutrition.md - Detailed nutritional protocols, DIAAS, timing
• periodization.md - Periodization models (LP, DUP, Block)
• supplements.md - Complete tier-based supplement overview
• recovery.md - Recovery strategies, sleep, CWI warning, hormonal optimization
• cardio-interference.md - Cardio integration, AMPK-mTOR, interference minimization
• techniques.md - Advanced techniques (drop sets, myo-reps, BFR)
• programs.md - Sample programs by level
• exercises.md - Exercise database, SFR, substitutions
• female-training.md - Female-specific training considerations
• injury-prevention.md - Injury prevention and management
• progress-tracking.md - Progress tracking, metrics, apps
• age-specific-training.md - Training adjustments by age group (youth, masters, seniors)
• psychology.md - Training psychology, motivation, adherence, habit formation
• glossary.md - Quick reference for training, physiology, and nutrition terms
• sample-logs.md - Example training logs for different phases and levels
• volume-landmarks.md - Detailed volume landmarks (MEV/MAV/MRV) by muscle group
• meal-plans.md - Konkrétní příklady jídelníčků pro bulk/cut/recomp

Quick Navigation by Topic

| If you need... | Start with | Then see | |----------------|------------|----------| | Build a plan from scratch | programs.md | periodization.md → exercises.md | | Optimize nutrition | nutrition.md | supplements.md | | Break through plateau | periodization.md | techniques.md → recovery.md | | Understand the science | mechanisms.md | glossary.md | | Train with injury | injury-prevention.md | exercises.md (substitutions) | | Prepare for competition | programs.md (competition prep) | nutrition.md (cutting) | | Optimize hormones naturally | recovery.md (hormonal section) | nutrition.md | | Body recomposition | nutrition.md (recomp section) | programs.md | | Konkrétní jídelníčky | meal-plans.md | nutrition.md |

Plan Creation Workflow

When creating a complete training program:

1. Gather info → Age, goals, experience, schedule, equipment
2. Read `programs.md` → Select appropriate split
3. Read `exercises.md` → Choose exercises per muscle
4. Read `periodization.md` → Structure mesocycles
5. Read `nutrition.md` → Set macros and timing
6. Optional: `calculators.py` → TDEE, protein, volume

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Calculators

The scripts/calculators.py script provides common training calculations:

| Command | Description | Example | |---------|-------------|---------| | tdee | TDEE calculation (Mifflin-St Jeor) | python3 scripts/calculators.py tdee 80 180 30 m moderate | | macros | Macronutrient targets by goal | python3 scripts/calculators.py macros 80 2500 bulk | | 1rm | Estimate 1RM from submaximal lift | python3 scripts/calculators.py 1rm 100 8 | | protein | Protein needs by status | python3 scripts/calculators.py protein 80 bulk intermediate | | weekly-volume | Volume assessment vs landmarks | python3 scripts/calculators.py weekly-volume 6 2 | | volume | Training volume metrics | python3 scripts/calculators.py volume 4 10 80 | | rir | RIR to %1RM conversion | python3 scripts/calculators.py rir 2 |

Usage:

python3 scripts/calculators.py  [args]

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Key Researchers

• Brad Schoenfeld (Lehman College) - Hypertrophy, volume, mechanisms
• Stuart Phillips (McMaster) - Protein, mechanical tension
• Eric Helms (AUT) - RIR/RPE, natural bodybuilding
• Mike Israetel (RP Strength) - Volume landmarks
• Milo Wolf (Updated 2025) - Lengthened partials research, multi-site trials
• James Krieger (Weightology) - Meta-analyses
• Michael Zourdos (FAU) - DUP, autoregulation

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Sources

1. Schoenfeld BJ et al. (2017). Strength and hypertrophy adaptations. J Strength Cond Res. PMID: 28834797
2. Schoenfeld BJ et al. (2016). Effects of resistance training frequency. Sports Med. PMID: 27102172
3. Morton RW et al. (2018). Protein supplementation meta-analysis. Br J Sports Med. PMID: 28698222
4. Wolf M et al. (2023). Partial vs full ROM resistance training: A systematic review and meta-analysis. Int J Strength Cond. DOI: 10.47206/ijsc.v3i1.182
5. Roberts LA et al. (2015). Cold water immersion and muscle hypertrophy. J Physiol. PMID: 26174323
6. Schoenfeld BJ et al. (2010-2022). Multiple meta-analyses on hypertrophy mechanisms.
7. Roig M et al. (2009). The effects of eccentric versus concentric resistance training on muscle strength and mass in healthy adults: a systematic review with meta-analysis. Br J Sports Med. PMID: 18981046
8. Wackerhage H et al. (2019). Molecular mechanisms of muscle hypertrophy. Eur J Sport Sci. PMID: 30741116
9. Kassiano W et al. (2023). Greater gastrocnemius muscle hypertrophy after partial ROM training at long muscle lengths. J Strength Cond Res. PMID: 37015016
10. Kassiano W et al. (2023). Which ROMs lead to Rome? Systematic review of ROM effects on hypertrophy. J Strength Cond Res. PMID: 36662126
11. Krieger JW (2010). Single vs. multiple sets of resistance exercise for muscle hypertrophy: A meta-analysis. J Strength Cond Res. PMID: 20300012
12. Da Silva JJ et al. (2023). Effects of eccentric vs concentric resistance training on strength and hypertrophy. J Strength Cond Res. PMID: 36989393
13. Zourdos MC et al. (2016). DUP vs traditional periodization for strength gains. J Strength Cond Res. PMID: 26398700
14. Grgic J et al. (2018). Effects of training frequency for muscular strength: A systematic review and meta-analysis. Sports Med. PMID: 29470825
15. Wolf M et al. (2025). Lengthened partial ROM resistance training is equally effective as full ROM training. PeerJ. PMID: 39959841
16. Wolf M et al. (2024). The effects of lengthened-partial range of motion resistance training of the limbs on arm and thigh muscle cross-sectional area: a multi-site cluster trial (preprint). SportRxiv. DOI: 10.51224/SRXIV.485
17. Pelland JC et al. (2025). The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains. Sports Med. PMID: 41343037
18. Piñero A et al. (2024). Throwing cold water on muscle growth: A systematic review with meta-analysis of the effects of postexercise cold water immersion on resistance training-induced

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Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: disco-trooper
• Source: disco-trooper/skills
• License: MIT

Install and usage instructions live in the source repository linked above.