Question: how to do your 1 rep max?
Answer: Work Out Your Weight Calculate your 1RM using these formulas*. For your upper body, find the heaviest weight you can lift 4-6 times and plug it into this equation: (4.6RM X 1.1307) + 0.6998. So if you can do 5 reps of 60kg, then according to the formula – (60 x 1.1307) + 0.6998 – your 1RM will be 68.5kg.