1RM: One Rep Max Estimation and Testing

A 1RM is the maximum load an athlete can lift once; it can be tested directly or estimated from sub-maximal sets.

Key takeaways

Test 1RM directly only when peaking
Use e1RM (estimated) for ongoing programme loading
Brzycki most accurate at ≤5 reps
Update e1RM continuously from logged sets

Definition

A One Rep Max (1RM) is the heaviest load an athlete can lift for a single repetition with sound technique. It is the reference point for percentage-based programming and a key strength benchmark.

Estimation formulas (e1RM)

Epley: 1RM ≈ weight × (1 + reps/30). Most popular general-purpose formula.

Brzycki: 1RM ≈ weight × (36 / (37 − reps)). More accurate at low rep ranges (≤5).

Lombardi: 1RM ≈ weight × reps^0.10. Smooth across rep ranges.

Modern coaching uses e1RM updated from every working set so the system always knows the athlete's current strength without forced testing days.