Understanding Percentages and Autoregulation


By Luke Duross

If you’ve been at CFM for a while you have probably noticed that we sometimes work off percentages of a one rep maximum when doing strength work in each lift. You may have also noticed that recently, we are using percentages less and less. In this article I will explain why we are moving away from percentages, and what you can expect to see in the future.

Here’s a rundown of percentages as it pertains to the 1 RM and some potential misconceptions some of you may have.

Hypothetical scenario. You and I are maxing out on back squat. If I max out at 300 lb and you max out at 350 lb and it is a true maximum test of absolute strength…we both pushed ourselves to our absolute maximal limit, you and I are both working just as hard relatively speaking because we both are lifting 100% of what we are physically capable of. There is no way you can elevate the effort of someone’s 100% effort over another. The weight may be different but the intensity of effort is the same. This is true.

Still you and me…another hypothetical scenario. We are both doing a set of 8 reps on back squats at 80%. A traditional rep max calculator you find online would tell you that the maximum amount of reps you should be able to perform in a movement at 80% is about 8. So if you and I are both doing 80% of our one rep max for 8 reps, you would think we are both working just as hard, right? Furthermore, this should mean that if you put 80% of your one rep max on the bar and pump out 11 reps, you are stronger than your one rep max indicates.


WRONG(most likely, you usually are)

At least not necessarily.

If we both take 80% of what we just hit for our 1 RM and perform the same number of reps, I can guarantee you one of us is working harder than the other person. I can also guarantee you that if we both hit as many reps as we possibly can at 80%, those numbers are going to be different.

There are a couple reasons for this. When it comes to calculating your one rep max based on maximum repetitions, the farther away you get from 100%, your ability to lift the bar becomes less about your absolute strength and more about your muscular endurance, neuromuscular efficiency, and movement efficiency. And there is A LOT of variance between people when it comes to those physical characteristics.

One of my favorite research studies to refer people to on this topic is this one
This study took a group of weightlifters and a group of track athletes. They found each participant’s one rep max. Then, over the course of 2 weeks, they tested each athlete’s maximum number of repetitions at 70, 80, and 90% of their achieved 1 RM. They then compared the two groups’ results. They also included the test results from two other similar studies.

First off, GROSS, I cannot imagine doing a max out at 70%. But more importantly, the results were pretty crazy.

One of the participants was able to do 70% forty times; another participant, only 12. One dude hit 80% for 20 reps and one dude petered out at 8. I won’t go into more detail; you can check it out for yourself, which I encourage. But you can clearly see just how much difference there is from person to person; and why trying to use absolute percentages, especially when prescribing it in a group setting, will generally miss the mark regarding the intended intensity. People come in all shapes and sizes, strengths and weaknesses, and genetic variances.

Another scenario where percentage-based training can be problematic is the days where you walk into the gym and pick up and empty bar and wonder who turned up the gravity. Some days 80% feels like 90% and visa versa. Strength and other physical components fluctuate from day to day. So on days when your 80% isn’t your 80%, why would I have you do 80%. In order to adjust to how you feel on a given day, you must do just that: feel.

Telling someone to build to a heavy but not maximal set of 5 and then do 4 sets of 5 at that weight, rather than giving them 5 x 5 @ 82% allows that person to adjust to how they feel that day, and not feel like they have to stick to the 82% of their all-time PR that they hit two and a half years ago before they had 9 kids, 2 c-sections, a hip replacement and filed bankruptcy.

Programming options that allow you to work within a moderate, moderately-heavy, heavy range for given set provide lenience, as well as room to push yourself if you are capable beyond what your percentage would indicate. Learning how feel what your capacities are on a given day and being able to autoregulate your training is a skill, and on well worth developing.

If you have any questions about this topic, come see me in the gym.