Use this protocol for testing any 1RM - for lifters who are not competing and are doing this for other reasons, we recommend only testing once every 6 months.
Note: Only test after lifting heavy for a period of time - including small sets of 6 reps @85% 1RM.
Warm up well beforehand, have someone spot you on any lifts going above your midline (deadlifts can be done alone). Ensure your technique is on point.
Guess what your 1RM could be - if you are doing 12 reps at 50kg then this number is approximately 70% of your 1RM.
Include 10 reps @ 50% 1RM in your warm up.
Rest 3-5 mins between sets. Even when you may not feel you need to.
Test
Use this 1RM in other strength and lift programs.