One-rep max estimator
Estimates the maximum load for one repetition from a set taken to (or very near) technical failure, and builds a percentage table for programming.
Inputs
Results
Estimated 1RM (average of both)
–
| %1RM | Load (kg) |
|---|
The formula
Epley: 1RM = load × (1 + reps ÷ 30)
Brzycki: 1RM = load × 36 ÷ (37 − reps)
Brzycki: 1RM = load × 36 ÷ (37 − reps)
Limitations
- Most accurate for sets of about 2–10 repetitions taken close to failure; accuracy falls with higher reps.
- Equations differ between exercises and between trained and untrained people.
- Estimates assume consistent technique and range of motion.
- Use the estimate to plan loads, then adjust with RPE/RIR in the session.
Important
Heavy single-repetition testing should only be done with good technique, an appropriate warm-up and spotting or safety equipment. Estimating from submaximal sets is safer for beginners and older adults.
Sources
- Epley B (1985). Poundage chart. In: Boyd Epley Workout. Lincoln, NE: Body Enterprises.
- Brzycki M (1993). Strength testing — predicting a one-rep max from reps-to-fatigue. JOPERD 64(1):88–90.