The issue with 1RM
I saw a discussion in the StrongFirst forum a few days ago, about 1RM with ketllebells and how it would relate to 1RM with a barbell. To be honest, I was not really interested in the details of the conversation, as technical differences and anatomic specificities make any kind of general rule from one lift to another quite inacurrate.
Other discussions tried to figure out the relation between xRM (usually 3 or 5), 1RM, and how to program cycle of PTTP, knowing one’s 1RM. This is where I started to really think the whole concept of xRM is an issue. At least for novice and intermediate trainees, who form the vast majority of the training population.
What is a xRM? It is the weight you are able to lift x times. A 1RM would be the maximum weight we can lift once. A 5RM the weight we can lift 5 times.
Here we can see the first issue. Is a 1RM the absolute max? If so, testing it will take so much of the trainee that he will need quite some time to recover. Typically, a true 1RM should be attempted in a strength competition only. So for the average trainee? It is more a sort of max (as Dan John would call it). The maximum weight a trainee has lifted, but not the maximum he could lift. And a 5RM? Do we want 5 nice reps, or just 5 reps that follow a minimum standard? Here again, the concept is so blur that master SFG Fabio Zoni created xTRM, or Technical rep max, i.e. the maximum weight one can lift with technically sound form for x reps.
At this point, we already are unable to really well define, and even less determine, what is the xRM of a trainee.
Additionally, I firmly believe that any xRM determination is useless, unless a trainee is already fairly advanced in strength training. I would add that it is unsafe.
A novice, as defined by Mark Rippetoe, is someone who is so far from his genetic potential, that he can basically progress every training session. It means that his xRM will change every session! An intermediate, where most of regular trainees stays after some time, can progress basically every week or so. His xRM progress several times a month. Why spend time and valuable energy to test a xRM that will not be valid more than a few weeks?
Testing a true xRM requires to maximallu tense muscles. It is a skill that few novices and not so many intermediate possess. This is a very unsafe test.
Experimented strength coaches do not test xRM with their trainees. Mark Rippetoe would have a novice start with an empty bar, do 5 reps, add some weight, do 5 more reps, and when the bar starts to slow, do 2 more sets at the same weight and stop there. This is very far from the 5RM of the individual. This is enough to start his flagship program Starting strength.
A StrongFirst instructor will probably use a 5ETRM to start (Easy technical rep max), and I am convinced that it would be very close to the 5 reps Rip would find with the method above. The goal is to find a weight that is reasonnably challenging, but not a truggle, to start a program. No need for maximum test.
Of course, you could be a powerlifter running a special 6-weeks squat routine, where you need to know your 1RM. But then, you are more than an intermediate, right?