TAKEN-RACK SWAP · 100% MUSCLE OVERLAP

Back extension vs Glute Hyper Extension

FR : Back extension ↔ Hyper extension fessier

Swapping Back extension (Machine) for Glute Hyper Extension (Machine) retains 100% overlap; expect externally braced cam track. Compare exact 17-muscle fractional recruitment before swapping equipment mid-session.

Weighted Muscle Overlap
100%
Sum of min(coef A, coef B)
Primary Equipment
Machine → Machine
Same rep/load measurement family
Load Transfer Protocol
Target RPE 7.5–8.5
Never assume 1:1 kg across leverages

Side-by-Side 17-Muscle Recruitment Delta

How primary mover (1.0× set) and synergist (0.5× set) allocation changes when swapping Back extension for Glute Hyper Extension.

Muscle Group Back extension Glute Hyper Extension Leverage Shift
Hamstrings Primary (45%) Primary (45%) Matched
Glutes (Gluteus Maximus / Medius) Primary (35%) Primary (35%) Matched
Lower Back (Spinal Erectors) Secondary (20%) Secondary (20%) Matched

Load & Volume Conversion: Back extension → Glute Hyper Extension

Worked weight heuristic: a 115 kg set on Back extension (Machine) maps roughly to 115 kg on Glute Hyper Extension (Machine; 5 kg jumps, curve: cam-matched resistance across sticking points). Calibrate set 1 at RPE 8 so e1RM history for Back extension remains unskewed. Zero anatomical muscles are dropped between Back extension and Glute Hyper Extension; 1:1 weekly set volume carries straight across.

Supporting Sports-Science Literature

Study Title Lead Author & Year Verified Link
Influence of joint position on electromyographic and torque generation during maximal voluntary isometric contractions of the hamstrings and gluteus maximus muscles. Worrell (2001) PubMed 11767248 ↗
Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. Plotkin (2022) PubMed 36199287 ↗
Effects of Adding Inter-Set Static Stretching to Flywheel Resistance Training on Flexibility, Muscular Strength, and Regional Hypertrophy in Young Men. Nakamura (2021) PubMed 33916599 ↗
Hip thrust and back squat training elicit similar gluteus muscle hypertrophy and transfer similarly to the deadlift. Plotkin (2023) PubMed 37461495 ↗

Related Biomechanical Swaps