Skewed 1RM max calculations...

[danimal1991]

Hey Rip, I'm sure your familiar with the equation weight x reps x .0333 + weight= estimated 1RM. I have been using this equation and I have noticed a strange phenomena when comparing estimated 1RM with my squat. For instance, I have squatted 285 for a set of 9 which estimates my max at around 370. But then, when I start to do reps with a weight above 90% of my 1RM, like tonight i did 320 only for a set of 3, this estimates my max at only about 350, and this is usually the case when using heavier weights, where I would think I could hit 4 or 5 reps with 320, I fall short.

So, after pondering this a bit, I thought maybe since with the heavier weight, as i tire throughout the set, any discrepancies in my form is compounded, and since the heavier weight is much less forgiving, it results in failed rep, thus ending the set. But with the lighter weight any slight errors may not have such a huge detrimental effect, so I am able to perform more reps.

Have you noticed this at all in your experience ? Or do I just suck at doing reps with heavier weight ?

[Mark Rippetoe]

1RM calculations do not work reliably. There is too much individual variability. Not your fault.

[stickman]

1RM calculations do not work reliably. There is too much individual variability. Not your fault.

Question for you then - in an earlier post you said that 1RM deadlifts are only for the meet. I get that 1RM deadlifts are not smart training tools - but since you can't accurately predict 1RM from your (say) 5RM - how to you recommend planning for the meet? Presumably you have to have a go at some 1RMs at some point - but I guess you also don't want to mess with your training too much. What have you usually done with the competitors in your care?

[Mark Rippetoe]

I know from the progress of training and his level of advancement about what a guy can do for a 1RM. I can tell from a heavy set of 5 about where the opening attempt should be. After watching the 1st attempt, we decide from there whether to do a 2nd and 3rd, or just a 2nd.

[stickman]

Any advice for guys who might want to compete but don't have a Rip to guide them? Am toying with the idea of entering a masters' event ...

[Mark Rippetoe]

Go to the meet, open with something you can triple, and go from there.

[Keg]

The "open with something you can comfortably triple" is a rule of thumb you will hear/see all over powerlifting.

[Dalp]

That formula really only works well if you're dealing with five reps or fewer.

[OCG]

I know from the progress of training and his level of advancement about what a guy can do for a 1RM. I can tell from a heavy set of 5 about where the opening attempt should be. After watching the 1st attempt, we decide from there whether to do a 2nd and 3rd, or just a 2nd.

Yeah, having trained for a while, I can tell about where my 1RM based upon my worksets. Probably not as reliably as an impartial coach though. It's just something you pick up I think.

[stickman]

That formula really only works well if you're dealing with five reps or fewer.

Not even 5 reps, at least, not for my deadlift. I can calculate a reasonable estimate of my 1 RM for bench and squat from the 5RM, but the 5RM deadlift seems to way underestimate what I can do for 1 RM. Of course, my form for the 1 RM ain't pretty, which may have something to do with it.

"opening with something you can triple" sounds like a very sensible starting point.