What is One-rep max (1RM)?

Your one-rep max, or 1RM, is the most weight you can move for exactly one rep before form breaks down. It is a way to measure strength on lifts like the squat, bench press or deadlift, and many programmes use it to decide how heavy your working sets should be.

Most beginners should not test a true 1RM, because it is tiring and risky without a spotter. Instead, lift a weight for several reps and use a calculator to estimate it. For example, if you bench 40 kg for 8 clean reps, your estimated 1RM is roughly 50 kg. Anyone with a health condition should check with a doctor before heavy lifting.