I did a couple of cycles of 531 in the past and one thing that always puzzled me was the PR's ie you do the last set and go all out to set a PR however first off your told not to train to failure and to hold a rep or two back so how are you going to break a record if your not going all out until you can't complete another rep ?

The other part I don't understand is the PR its self ie if I up the weight by 5 and 10 pounds each cycle i'm never actually lifting the same weight so how do I know if I've done better ?

My conclusion is i'm going for more reps than I did before with the 85%,90% and 95%, ie the first cycle perhaps I did 6 reps with my 85% weight and in the next cycle I get 7 reps with my new heavier 85% so I have a PR OF 1 rep would this be correct ?

Although I can't see how its possible to keep doing this with heavier and heavier loads especially when holding a rep or two back..... please could someone explain what i'm missing sorry for being a bit slow.