Max effort back squat
5-4-3-2-1-1-1-1
Proceed by following steps:
5r @ 40%, 4r @ 50%, 3 @ 60%, 2r @ 70%, 1r @ 80%
At this point rest 2-3min
1st. 1r @ 90%
2nd 1r @ 95-97%
3rd 1r @ +100% (new pr attempt)
3-5min recovery between last 3 sets.
Do not overestimate the weights on last set.
Be smart!