Talk:One-repetition maximum

The mentioned formula is not in error "mathematically" as stated, it may be in error empirically. the formula was not derived mathematically, it was derived by making observations, and some user suggests that it does not match their own measurements. —Preceding unsigned comment added by 130.207.37.176 (talk) 15:51, 3 September 2009 (UTC)
 * No, his point is that if you set r to 1, then the formula will tell you that 1RM = (1/30 + 1) * 1RM, which is nonsense. – Smyth\talk 13:03, 18 September 2009 (UTC)
 * That is not nonsense; it means try for a PR. This is nonsense, 135 lbs *(1+ 10^10 reps /30) = 45,000,000,135 lbs 1RM.

How did you figure this ecuation out?
I have been watching at these ecuations and I have been trying to figure out, how you figured them out, which factors you used etc. So I have a question, how did u find the numbers? You know weight / ( 1.0278 - ( 0.0278 * reps )). Where does the 1.0278 and the 0.0278 come from. What do they stand for? If someone could write in a long explanation for this, I would be truly joyed :)

(Trying to use the ecuations to make some experiments of my own, so need to know every factor there is in place)

Thank you in advance Jonas —Preceding unsigned comment added by 87.54.33.250 (talk) 09:32, 17 November 2009 (UTC)

The Epley formula should be renamed to the Epley-Arthur formula
I think Mike Arthur, who was Boyd Epley's assistant, should also be credited for coming up with the formula. I was curious about its origin, so I asked Boyd Epley directly, and he gave the following nice and interesting answer on 23. March, 2021:

"I was a pole vaulter for Nebraska but I had a background in Olympic lifting, powerlifting and bodybuilding. The University of Nebraska did not have a weightlifting team nor did they host any lifting meets so I started a team in the late 60’s. Mike Arthur was a freshman on the team and set the world record In the deadlift in the 132 lbs.weight class. In 1969 I was asked by the football coach to have the football team start lifting. I asked Mike to volunteer and eventually hired him as my assistant.

Both of us wrote down our poundages for each lift in our workouts for many years before we came up with the formula in an effort to show the players where they stood in terms of a 1rm for the workouts they were doing. We also tested their strength levels. After working with them for a few years we were able to guess their strength level by watching how many reps they could do with a weight. Mike actually tweaked the formula so we could prescribe training poundages based on their predicted strength levels. We tried several methods and I give Mike credit for finding the simplest and most effective way to predict your strength level.

We created charts in the weight room for the athletes and started putting that information in our training manuals. The book [Boyd Epley Workout] came many years later. At that point I was getting a lot of recognition for being the Nebraska Head Strength Coach so we decided if we called that manual the Boyd Epley Workout in might sell more copies. It brought in around $100,000. I don’t remember the formula being called the Epley formula. I have never wanted to take full credit for it because Mike Arthur is the one that actually made the final calculation that we use for the formula.

The National Strength and Conditioning Association which we started in Lincoln in 1978 did a study in the last year or so that determined our formula was the most accurate way to determine 1RM."

Martin — Preceding unsigned comment added by 46.162.108.90 (talk) 12:33, 6 April 2021 (UTC)

McGlothin formula and others
https://www.fxsolver.com/browse/formulas/One-repetition+maximum+%28McGlothin+formula%29 See Also Other Formulas From:
 * https://www.unm.edu/~rrobergs/478RMStrengthPrediction.pdf
 * https://doi.org/10.1002/acr.20368