Does the number of reps matter? Yes. Why? I’ll tell you

Jason Momoa on climbing; anger management; we should do a fast of "dopamine fasting." This is Link Letter 85!

Does the number of reps matter? Yes. Why? I’ll tell you
Brad Schoenfeld, hallowed be thy name

A few days ago, esteemed author and philosopher Olùfèmi O. Táíwò cc’d me into a question on Bluesky (follow me) about whether rep ranges—how many times you lift a weight in a set—matter. Fortunately for him and very unfortunately for me, the term “rep range” is a madeleine for me. So here we go with a sort of free Ask A Swole Woman on not only a Friday, but the very Friday that the long-anticipated Legend of Zelda: Tears of the Kingdom is being released, so you know the “rep range” fugue state is very powerful indeed.

For many years, “how many reps when lifting weights” is a question that has confused and intimidated the masses. Most people still think they need to do lots dozens and dozens of reps to “tone and lengthen.” Debates have especially raged over which “rep range” will produce the largest and juiciest-looking muscles. Some said it was 8-15 reps; others said 6-12 reps; still others, attempting to broker peace between the two warring sides, would say it was 6-15. Understandably, this tended to hurt more than it helped, and drove the 8-15 bros and 6-12 dudes even further apart. Still more factions emerged under the banners of 8-12 and 12-15, and they splintered and perished. Times were dark; tensions were high. It seemed the weight rooms of gyms might never know peace.

And then along came Brad Schoenfeld and Co., who laid hands upon the bros and dudes of the land, and yea Brad said unto them: “My fellas; my champs; my guys. Lay down your swords, for it is not the number of reps that matter. Thou must use sufficiently heavy weights, at least 30 percent of thy one-rep max, and thou mayest not cast the weights down until thou hast completed enough reps that thy muscles ache with exertion and cry out for relief. It is then and only then that thy muscle tissues shall be sufficiently shredded as to produce hypertrophy.” And Brad withdrew his hands, and it was so.[^1]

What was the specific, scientific finding? In 2021, Schoenfeld published a study that broke down how muscles can be trained in basically three dimensions, three different ways:

Strength: <6 reps for probably >RPE 7 (which will probably be <80% of your 1RM). Building muscle strength has the most specific rep needs (sets of fewer than 5, for weights that are at least a 7/10 or so on the effort scale).

Endurance: pretty much whatever till you are tired. Building muscle endurance will happen from doing pretty much anything until your muscle gets tired, and then doing it for a little longer than that.

Size: At least 30% of 1RM weight, for as many reps as needed to get near failure with that weight (probably RPE 8 or more). Building muscle size happens when you use decently heavy weights (at least 30% of your one-rep max) but less weight than would put you in the “strength” range, to the point of failure or near-failure (an 8-10/10 on the effort scale).


The first two things we’ve known for a pretty long time. The last one was a fairly big deal, because it suggested that it’s possible to make muscles bigger with much lighter weights than we previously thought (you can probably lift 30% of your 1RM for 25 reps or more). That would make the hypertrophy rep range something like 6-25+ reps.

A lot of outlets took this and ran with it, using headlines that suggested that the number of reps you do or weights don’t matter. This is wrong.

However, does it mean the opposite, which is that if you don’t want your muscles to change at all in size, you have to do either 50 million reps, or less than 5, and never the ‘twain shall meet? Also no. Here is why: Muscles cannot grow infinitely large regardless of what weight you are using. If you can only lift a two-pound dumbbell for 25 reps, doing that every other day for the next 10 years will not make you look like Arnold Schwarzenegger. It will not even make you look like Brie Larson or Viola Davis.

‘How Do I Get a Big Juicy Ass in Time for Summer?’ — Ask A Swole Woman
Every influencer is promising the cheeks of your dreams, but only a few will deliver.

Because the converse of the rules above is also true: Any random number of reps will not allow you to lift more and more weight. You need to train in the strength range to be able to lift a decent amount of weight, and then lift that decent amount of weight for anywhere from 6-25+ reps to actually build up your muscle size.

Many are also confused about whether this means, say, lifting ten pounds for 6 reps does the same thing as 10 pounds for 25 reps. Also no. If you are lifting ten pounds, as long as that is more than 30% of your one-rep max, you have to do as many reps as gets you to almost failing the next rep with that weight, in order for it to affect your muscle size.

(How do you know if it’s more than 30% of your one-rep max? If you can do 25 reps or way, way more than that, it probably is not.)

(How do you know if you are at “almost failing”? Keep going, just as a test once in a a while. You will find out. Oh, will you find out.)

Does that mean even if you get really strong, you will be huge? Also no: Muscle is very hard to build, and it takes a long time. You don’t go from squatting 5 pounds to squatting 135 pounds in days or even weeks. You also probably need to do a lot more sets of those high reps than you think. You still need lots of food and water and rest to grow muscle size, too (a thing that everyone loves to conveniently forget). If you are afraid lifting ten pounds for 6 reps or 25 reps once will be the death of your comely physique, I’m sorry, but I’m laughing. It won’t happen from once, once a week, twice a week, three times a week, even ten times a week. It takes a lot, I’m saying! It takes a whole program done for months to even begin to knock at the door of anything resembling noticeable physical change. (A program that is doable, but nonetheless specific in its intention.)

To sum up: Rep ranges specifically for building muscle size—I’ll say it again, for muscle size, which is not the same as muscle strength, or muscle endurance—are not as specific as most people had thought for a while. That doesn’t mean that any number of reps is the same as any other number of reps. Doing 100 reps with a two-pound weight is not the same as 10 reps with a 20-pound weight. But!: reps don’t matter so much that precisely 11-rep sets of curls will make your biceps massive, while 12 reps will disintegrate them into “toned and lengthened” Gwyneth Paltrow arms.

Just to be clear: This is not a guide to tell you how many reps to do when you walk into the gym. It's to help you understand what you are looking at when, for instance, a publication writes a "How to Get Strong" guide that tells you to lift 80% of your one-rep max for 8-12 reps, you will know that's bullshit. When a fitness influencer tells you to build strength by doing dozens of reps in circuits, you will know that's extra, extra bullshit. (If you want to know how many reps to do to get stronger: That's what LIFTOFF is for.)

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~Discord Pick of the Week: Checking in on acrobatics and tumbling, which is giving "old school circus performer" in the best way:


Celebrities are always recommending “two exercises,” but because it’s Arnold and because one of the exercises is deadlifts, I’ll allow it.

Jason Momoa on climbing:

“Maybe he’ll hit the heavy bag, pound some poi, throw back a Guinness, spin some vinyl, and watch climbing videos sent by his kids. ‘I make them send me clips all the time,’ he says. ‘I’m watching my heart climb up the wall. They’re children, but they’re so strong and confident and express themselves through movement. Sometimes you have to be dynamic, sometimes static and smooth, and you just get to explore. When they succeed, you feel the moment. I absolutely love climbing and encourage any parent to go experience it with their kids. That’s what my mom did with me.’
Momoa’s origin story involves a lot of climbing. His mom introduced him to it as a teen, and it became his passion. He lived the dirtbag life, climbing in remote spots around the world, living off sardines and crackers; those experiences still inform his outlook. ‘Climbing is what keeps me grounded in a chaotic world that just wants more of me. It keeps me centered, keeps me in the dirt, keeps me humble, and keeps me stoked.’ ”

Again the landmine Zercher curtsy lunge rears its head.



Katie Way first covered dopamine fasting at Vice all the way back in 2019, and regrettably, it has not died as a trend. (You cannot end-run around your hormones.)

What’s missing from anger management. This piece casually mentions the anger management teacher casually recommending Jordan Peterson and then it just… ends.

In the interest of hastening the discourse of people’s bodies, celebs need to do less of the Mindy Kaling “I just run 20 miles a week” (i.e. lying) to promote a swimwear line and more of Janelle Monáe’s “it’s the Jamaican food, and sex” (shoutout to Jason Momoa for contributing).

Leaving this here:

“Speaking at a panel on new obesity treatments at the STAT Breakthrough Summit in San Francisco on Thursday, one expert cited a large clinical trial for Wegovy that showed that about 40% of the weight participants lost was lean mass…
‘That’s what starvation does. You lose equal amounts of muscle and fat,’ said Robert Lustig, emeritus professor of pediatrics at the University of California, San Francisco. ‘If you’re a person 60 years old or over and you’re losing muscle, your risk of dying just went up exponentially. So we may be … robbing Peter to pay Paul.’ ”

If only someone had been saying this!

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Reverse basketball had me crying.



I thought the three YouTube videos of Bobby Fingers (where he makes painstakingly detailed dioramas that re-create the worst moments of bad men) would be beyond the Rubicon for me. I was wrong; the Mel Gibson one in particular is excellent.

And who am I kidding, I will not see the end of playing Tears of the Kingdom any time soon. Goodbye!!

That’s all for this week! I love you for reading, thank you, let’s go—

[F1] In serious, nothing is absolute gospel in the science of this stuff. This study has become the prevailing guideline, but in a few years, something else may happen. And further, this framework doesn't even get into time under tension and a few other variables that make rep ranges even more (!) meaningless. Just lift heavy, for probably fewer reps and with greater intensity than you think you should if you were raised by women's magazines and workout DVDs and so forth, and you're going to be 90% on track.