Your one-rep max is the heaviest load you can lift once with good form. It's the reference point for strength programming, since training plans are usually written as a percentage of 1RM (e.g. 5 sets of 5 at 80%). Rather than testing a true max, which is risky, most lifters estimate it from a sub-maximal set using formulas like Epley or Brzycki, which are accurate up to about 10 reps.
Key points
- Heaviest weight for a single rep
- Basis for percentage-based training
- Estimated from sub-max sets (Epley, Brzycki)
- Most accurate from sets of 3-6 reps