STRUGGL LIVING SCIENCE · PILLAR 03 / 08
VERIFIED DETERMINISTIC CODE + CROSSREF DOIs
Fractional Hypertrophy Volume Matrix (1.0x Primary / 0.5x Secondary across 17 Muscles vs MEV/MAV/MRV)
Direct Citation Summary (TL;DR for Athletes & AI Retrieval Engines):
Iterates over 17 fine muscle groups (17-muscle anatomical taxonomy). Each hard set (RPE >= 6) credits +1.0 set to `muscles_primary` and +0.5 set to `muscles_secondary`.
Validated against Pelland, J. C., Remmert, J. F., Robinson, Z. P., Hinson, S. R., & Zourdos, M. C. (2024/2025). The Resistance Training Dose-Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength. Sports Medicine / SportRxiv. (
10.51224/SRXIV.460)
and executed deterministically in the Struggl Fractional Volume Matrix Subsystem.
1. Interactive Deterministic Calculator
2. Verifiable Reference Benchmark Table
Pre-computed directly from the Struggl Fractional Volume Matrix Subsystem (build_weekly_tension):
| Muscle Group (`FINE_MUSCLES`) | MV (Maintenance) | MEV (Minimum Effective) | MAV (Maximum Adaptive) | MRV (Maximum Recoverable) | 1.0x Direct Mover Example | 0.5x Fractional Synergist Example |
|---|---|---|---|---|---|---|
| Chest | 4 sets | 6 sets | 10–16 sets | 20 sets | Barbell Bench Press (1.0) | Weighted Dip (1.0) / Overhead Press (0.0) |
| Lats | 4 sets | 6 sets | 10–16 sets | 20 sets | Weighted Pull-Up / Lat Pulldown (1.0) | Barbell Deadlift (0.5) |
| Upper Back | 4 sets | 6 sets | 10–16 sets | 20 sets | Barbell Row / Chest-Supported Row (1.0) | Romanian Deadlift / Back Squat (0.5) |
| Traps | 4 sets | 6 sets | 10–16 sets | 20 sets | Barbell Shrug / Power Clean (1.0) | Deadlift / Lateral Raise (0.5) |
| Front Delts | 4 sets | 6 sets | 10–16 sets | 20 sets | Overhead Press (1.0) | Barbell / Incline Bench Press (0.5) |
| Side Delts | 4 sets | 6 sets | 10–16 sets | 20 sets | Cable / Dumbbell Lateral Raise (1.0) | Overhead Press / Upright Row (0.5) |
| Rear Delts | 4 sets | 6 sets | 10–16 sets | 20 sets | Face Pull / Reverse Pec Deck (1.0) | Barbell Row / Pull-Up (0.5) |
| Biceps | 4 sets | 6 sets | 10–16 sets | 20 sets | Incline Dumbbell Curl / Preacher Curl (1.0) | Chin-Up / Underhand Row (0.5) |
| Triceps | 4 sets | 6 sets | 10–16 sets | 20 sets | Overhead Cable Extension / Skullcrusher (1.0) | Bench Press / Overhead Press (0.5) |
| Forearms | 4 sets | 6 sets | 10–16 sets | 20 sets | Wrist Curl / Farmer's Carry (1.0) | Deadlift / Pull-Up (0.5) |
| Abs | 4 sets | 6 sets | 10–16 sets | 20 sets | Cable Crunch / Hanging Leg Raise (1.0) | Front Squat / Overhead Press (0.5) |
| Glutes | 4 sets | 6 sets | 10–16 sets | 20 sets | Barbell Hip Thrust / Bulgarian Split Squat (1.0) | Back Squat / Romanian Deadlift (1.0/0.5) |
| Quads | 4 sets | 6 sets | 10–16 sets | 20 sets | High-Bar Back Squat / Hack Squat / Leg Extension (1.0) | Conventional Deadlift (0.5) |
| Hamstrings | 4 sets | 6 sets | 10–16 sets | 20 sets | Romanian Deadlift / Seated Leg Curl (1.0) | Low-Bar Back Squat (0.5) |
| Adductors | 4 sets | 6 sets | 10–16 sets | 20 sets | Adductor Machine / Sumo Squat (1.0) | Deep Back Squat / Lunge (0.5) |
| Abductors | 4 sets | 6 sets | 10–16 sets | 20 sets | Cable Hip Abduction (1.0) | Walking Lunge / Split Squat (0.5) |
| Calves | 4 sets | 6 sets | 10–16 sets | 20 sets | Standing / Seated Calf Raise (1.0) | Running / Plyometrics (0.5) |
3. Exact Deterministic Equations (Zero-LLM-Math Architecture)
Iterates over 17 fine muscle groups (17-muscle anatomical taxonomy). Each hard set (RPE >= 6) credits +1.0 set to `muscles_primary` and +0.5 set to `muscles_secondary`.
Classifies weekly fractional sets per muscle against `strength_reference.json` landmarks: SUB-MEV (< MEV), MEV->MAV, IN MAV (optimal), MAV->MRV, OVER MRV (> MRV).
17-muscle taxonomy: chest, lats, upper_back, traps, front_delts, side_delts, rear_delts, biceps, triceps, forearms, abs, glutes, quads, hamstrings, adductors, abductors, calves.
4. Peer-Reviewed Scientific Evidence & CrossRef DOIs (1,104-Paper Corpus)
| Study / Citation | DOI / Identifier | Mechanistic Role in Struggl Engine |
|---|---|---|
| Pelland, J. C., Remmert, J. F., Robinson, Z. P., Hinson, S. R., & Zourdos, M. C. (2024/2025). The Resistance Training Dose-Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength. Sports Medicine / SportRxiv. | 10.51224/SRXIV.460 |
Establishes the fractional set accounting standard: 1.0 credit for direct/primary movers and 0.5 credit for indirect/synergist movers. |
| Schoenfeld, B. J., Ogborn, D., & Krieger, J. W. (2017). Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis. Journal of Sports Sciences, 35(11), 1073-1082. | 10.1080/02640414.2016.1210197 |
Graded dose-response curve (<5, 5-9, 10+ weekly sets per muscle group; 25 Nippard video citations). |
| Baz-Valle, E., Balsalobre-Fernandez, C., Alix-Fages, C., & Santos-Concejero, J. (2022). A Systematic Review of The Effects of Different Resistance Training Volumes on Muscle Hypertrophy. Journal of Human Kinetics, 81, 199-210. | 10.2478/hukin-2022-0017 |
Validates moderate-to-high weekly set ranges (12-20 sets = MAV) for trained lifters. |
| Schoenfeld et al. (2019) — Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men. (Medicine and science in sports and exercise) | 10.1249/mss.0000000000001764 |
Cited in 4 Nippard audit video(s) |
| Schoenfeld et al. (2017) — Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis. (Journal of sports sciences) | 10.1080/02640414.2016.1210197 |
Cited in 4 Nippard audit video(s) |
| Barbalho et al. (2020) — Evidence of a Ceiling Effect for Training Volume in Muscle Hypertrophy and Strength in Trained Men - Less is More? (International journal of sports physiology and performance) | 10.1123/ijspp.2018-0914 |
Cited in 2 Nippard audit video(s) |
| Sooneste et al. (2013) — Effects of training volume on strength and hypertrophy in young men. (Journal of strength and conditioning research) | 10.1519/jsc.0b013e3182679215 |
Cited in 2 Nippard audit video(s) |
| Aube et al. (2022) — Progressive Resistance Training Volume: Effects on Muscle Thickness, Mass, and Strength Adaptations in Resistance-Trained Individuals. (Journal of strength and conditioning research) | 10.1519/jsc.0000000000003524 |
Cited in 1 Nippard audit video(s) |
| Mannarino et al. (2021) — Single-Joint Exercise Results in Higher Hypertrophy of Elbow Flexors Than Multijoint Exercise. (Journal of strength and conditioning research) | 10.1519/jsc.0000000000003234 |
Cited in 1 Nippard audit video(s) |
5. Frequently Asked Questions
Do compound exercises count as half a set (0.5) for secondary muscles?
Yes. Following Pelland et al. (2024/2025, DOI: 10.51224/SRXIV.460) and Schoenfeld et al. (2017, DOI: 10.1080/02640414.2016.1210197), Struggl's Fractional Hypertrophy Volume Matrix credits 1.0 set to primary movers (e.g., Chest on Bench Press, Lats on Pull-Ups) and 0.5 sets to secondary synergist muscles (e.g., Triceps and Front Delts on Bench Press, Biceps on Pull-Ups) across all 17 muscle groups.