Learn 5/3/1

One-Rep Max (1RM)

Your one-rep max (1RM) is the most weight you can lift for one clean rep on a good day.

5/3/1 uses it once — at setup — to derive your Training Max.

You don't need to test a true 1RM to start. A recent heavy set works: the app can estimate your 1RM from, say, "225 × 5" using the Epley formula.

Err on the low side. It's easier to bump a TM up than to dig yourself out of too-heavy weights.