Machine Leg Extension — Muscles Worked & RPE Load Guide
Machine Leg Extension targets Quadriceps as primary movers (1.0× set credit). Cam-matched resistance across sticking points.
17-Muscle Fractional Recruitment & Weekly MEV–MRV Landmarks
Each working set ≥ RPE 6 triggers fractional hard-set credit toward Renaissance Periodization / Schoenfeld weekly hypertrophy landmarks.
| Muscle Group | Mechanical Role | Effort Share | Weekly Optimal Band (MEV–MAV) | Frequency & Research |
|---|---|---|---|---|
| Quadriceps | Primary (1.0× set) | 100% | 8–18 sets/wk (MRV 20) | 2–4x / week · Evidence |
Machine Leg Extension Worked Wathan RPE Prescription Table (kg)
Worked kg values computed for Machine Leg Extension using a worked 165.0 kg reference 1RM (Machine) rounded to 5 kg machine increments. Mechanics: Externally braced cam track; resistance curve: Cam-matched resistance across sticking points.
| Reps | RPE 9.5 | RPE 9 | RPE 8.5 | RPE 8 | RPE 7 |
|---|---|---|---|---|---|
| 3 reps | 0 kg (88%) | 0 kg (88%) | 0 kg (85%) | 0 kg (85%) | 0 kg (82%) |
| 5 reps | 0 kg (82%) | 0 kg (82%) | 0 kg (82%) | 0 kg (79%) | 0 kg (76%) |
| 8 reps | 0 kg (76%) | 0 kg (76%) | 0 kg (73%) | 0 kg (73%) | 0 kg (70%) |
| 10 reps | 0 kg (73%) | 0 kg (70%) | 0 kg (70%) | 0 kg (70%) | 0 kg (67%) |
| 12 reps | 0 kg (70%) | 0 kg (67%) | 0 kg (67%) | 0 kg (67%) | 0 kg (64%) |
Strong, Hevy & French/English CSV Import Labels
STRUGGL automatically maps these exact workout-tracker strings to canonical Machine Leg Extension volume and e1RM records on zero-login Wrapped CSV upload.
Taken-Rack Substitutes & Biomechanical Swaps
Ranked deterministically by weighted primary-muscle overlap inside the same measurement family.
Verified Peer-Reviewed Literature (PubMed & DOI)
| Peer-Reviewed Paper | Author & Journal | External Reference |
|---|---|---|
| Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. | Plotkin (2022) · PeerJ | PubMed 36199287 ↗ |
| Hip flexion angle affects longitudinal muscle activity of the rectus femoris in leg extension exercise. | Mitsuya (2023) · European journal of applied physiology | PubMed 36795130 ↗ |
| Does the Muscle Action Duration Induce Different Regional Muscle Hypertrophy in Matched Resistance Training Protocols? | Diniz (2022) · Journal of strength and conditioning research | PubMed 33306588 ↗ |