Definition
1RM stands for one-rep max — the heaviest load you can move for a single rep on a given lift. It is the standard reference for prescribing training intensity (e.g. '80% of 1RM for 5 reps'). You can test it directly or estimate it from a 3–8 rep set using the Epley formula: 1RM = weight × (1 + reps/30).
Real questions
How do I calculate my 1RM without testing?
Use the Epley formula: take a set of 3–8 reps, then 1RM ≈ weight × (1 + reps/30). For example, 225 × 5 = ~262 lbs.
How often should I test my 1RM?
Every 8–12 weeks at most. Testing is taxing; most lifters get better results training submaximally and re estimating from heavy triples.
Stack with
Put it to work
Coach Foster builds your program around 1rm (one rep max) and the rest of the fundamentals, shaped to your body and your week.