Using sets across to estimate 1RM

[67629]

Obviously, an estimate of 1RM is just that: an estimate, and one's true 1RM can only be found by actually attempting it.

However, I remember reading in your books that a 10RM is about equal to 75% of 1RM and that a 20RM is about equal to 80% of 1RM. What I do not remember seeing in your books is what 3x5 roughly equates to as a percentage of 1RM.

As a fairly random guess, I figure about 80-85%; but, I'm sure you have an infinitely more educated guess based on your vast experience. I would greatly appreciate it if you could educate me.

[Mark Rippetoe]

It varies so much with the individual, as I've observed before, that it's not a useful calculation. Your 80-85% is probably close. But since I don't do or program 1RM-based training, and since I have seen many missed attempts that should have been made, I am reluctant to engage in this type of speculation.

[elVarouza]

I've never found 1RM calculators to be too useful. It depends on the lifter, the day, recovery, etc.

For example, when my deadlift 4RM was 365lbs (went for 5 and missed it) I had a PL meet coming up. Some calculator told me my projected 1RM was 396lbs, so I was really hoping to hit 400lbs at the meet. Well, my second attempt was an easy 395lbs, and my third attempt was a not-very-challenging 415lbs.

My squat and bench were also higher than expected. Moral of the story is the best way to find out a 1RM is to do it unless something prevents you (injury, fear of injury) or if it doesn't fit into your programming.

[Andy Baker (KSC)]

Also useful to know that estimation with these types of formulas are impossible with novices and females. I know Rip will agree, but it is not uncommon for a female athlete to bust out a set of 10 with weight not too far from a 1RM.

It has been my observation that a well trained relatively experienced male's 5RM is just a tad over 85%1RM (on the squat).

[william jackson]

historically, my 1RM has been within +/- 1% of 87% of my 3x5 weight. but ive only tested a 1RM twice so it is not a very large body of data to draw conclusions from

[67629]

Fair enough. Thank you for the reply.