Speaker A
What if half the time and effort you're spending in the gym isn't actually doing anything?
Jeremy Ethier's 10-week experiment with 200 lifters compares 6-day vs 3-day push-pull-legs splits to see which builds more muscle, finding similar growth.
Key Takeaways
- Training 3 days per week with half the volume produced muscle growth statistically similar to training 6 days per week.
- Higher training frequency and volume may not translate into proportionally greater muscle gains, especially when sustainability and recovery are considered.
- Adherence and enjoyment matter: the lower-volume group found training easier to maintain and more motivating.
- Subjective confidence and perceived effort do not reliably indicate which program builds more muscle.
What the video covers
- Jeremy Ethier challenges the assumption that more gym volume and frequency always produce more muscle growth.
- 200 lifters were randomly split into a 6-day-per-week push-pull-legs group (about 20 sets per muscle per week) and a 3-day group with half the volume.
- Both groups followed a small calorie surplus with a minimum protein target, tracked via an app, with non-compliant participants removed.
- Growth was measured weekly using circumference measurements of flexed and unflexed muscles, a method chosen to allow a larger sample size.
- The 3-day group consistently rated workouts as easier and more enjoyable, while the 6-day group found them much harder.
- The 6-day group was more confident its program maximized growth, and the 3-day group reported feeling stronger and lifting heavier in later weeks.
- Statistician Dr. Eric Trexler analyzed the data independently after 10 weeks.
- Both groups achieved statistically significant growth: 0.83 inches combined for the 6-day group versus 0.75 inches for the 3-day group.
- The difference was not statistically significant, meaning the two groups grew essentially the same amount.
- Trexler notes this contradicts prior research predicting about 60% more gains from doubling volume, prompting further investigation.
Full Transcript — Download SRT & Markdown
Speaker A
What?
Speaker A
I know. I know how that sounds, but I just ran an experiment on over 200 people, and what we found went against everything I thought I knew about training.
Speaker A
I'll break down exactly what we did, why most studies never catch this, and how many workouts you actually need to get the best results.
Speaker A
Ever since I got into lifting, I've always been someone who trains a lot, usually with six hard workouts a week.
Speaker A
Because according to the latest research, the more sets you do at the gym, the faster you grow.
Speaker A
But most of these studies have only tested high volumes on one or two muscles at a time, not your entire body.
Speaker A
So, was I actually getting more gains training six days per week, or could I have gotten just as good of results training with half of that?
Speaker A
To find out, I just need to run one of the biggest experiments of my life on 200 real people.
Speaker A
That's Drew.
Speaker A
He's one of 200 lifters we recruited as part of our 10-week experiment, where each lifter was randomly assigned into one of two groups.
Speaker A
The first group, which Drew fell into, is training six days per week using a push-pull-leg split.
Speaker A
Pretty much the exact same routine I followed for years, with around 20 sets per muscle per week.
Speaker A
Now, the second group is also doing a push-pull-leg split, but only three workouts per week.
Speaker A
So, same general program, same muscles worked, but half the workouts and half the number of sets.
Speaker A
Coming off of working out six days a week, this is kind of nothing.
Speaker A
Like me and most of the subjects we pulled, Matt is predicting that the group training twice as much should build the most muscle.
Speaker A
He's even worried if he'll be able to build any muscle at all in this plan.
Speaker A
I don't know. I hope I don't get fat.
Speaker A
Now, to control everyone's nutrition, every subject followed a small calorie surplus with a minimum daily protein target, and everything was tracked in our Built with Science app.
Speaker A
And so, if we noticed anyone wasn't consistent, we kicked them out of the experiment.
Speaker A
We also made sure both groups were balanced for gender and had an equal number of beginners and intermediates in each.
Speaker A
And as for how we're measuring muscle growth, each week, participants are submitting circumference measurements of their flexed and unflexed muscles.
Speaker A
And while you might think this isn't the most accurate way to assess growth, a lot of studies, including some of your videos, Jeremy, take a smaller group of people and do these really high-tech body composition measurements.
Speaker A
But obviously, you can only do that with small groups of people.
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So, with this kind of design, what we do is sacrifice the high-tech body comp measurements so that we can expand out and get a more, you know, a larger, more representative sample.
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That's Dr. Eric Trexler, a statistician and muscle growth researcher who helped us design this experiment in the first place.
Speaker A
After the 10 weeks are up, he'll independently crunch the numbers and tell us exactly what happened.
Speaker A
But so far, after just three weeks of training, the six-day-per-week group is struggling to keep up.
Speaker A
This week, I missed a few morning workouts.
Speaker A
Had to do them at night after leaving the office.
Speaker A
I started to dislike the six-day split a bit.
Speaker A
This is where we quickly started to notice a big difference between our two groups.
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We actually asked all of our subjects to rate the difficulty of their program at the end of each week.
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Going into the gym only three days a week, I am giving 110% rather than cutting corners here and there.
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I'm totally digging the program so far.
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I've done a six-day routine in the past, but this program gives me energy.
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I wake up wanting to work out instead of dreading it.
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And in the first four weeks, the three-workout group consistently rated their workouts as feeling easier and easier.
Speaker A
Whereas in our six-workout group, it's a lot.
Speaker A
It's definitely tough to hit six days of the week.
Speaker A
My muscles are still sore when I work out.
Speaker A
Probably tougher than I expected.
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They ranked their workouts as much harder and never really got any easier.
Speaker A
But we also asked both groups to rank how much they thought their workouts were working.
Speaker A
I had a massage this week, and she said that she could tell my muscles were a lot stronger, a lot of definition, and like the V-shape.
Speaker A
I will say that my progress has been explosive.
Speaker A
If I look at week zero and now, there is a huge difference.
Speaker A
And while both the three- and six-day groups were confident their plans were working, the six-day group repeatedly seemed to believe their program was doing more to maximize growth.
Speaker A
And it seemed like that confidence was helping them push through even the most challenging of their workouts.
Speaker A
I feel nauseated, which causes vomiting after the leg exercise a couple of days ago.
Speaker A
Now I can relate to people who like to skip leg day.
Speaker A
Meanwhile, some members of our three-day group weren't sure if they were seeing results at all.
Speaker A
My belly's growing.
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The rest of me is kind of staying the same.
Speaker A
I do not feel any stronger nor fitter.
Speaker A
So, at this point, I would say our six-workout group not only had over a decade's worth of research predicting they would win, but they also seem to have a clear advantage in confidence as well.
Speaker A
Been telling myself to stop whining and wake up when the alarm is on.
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I'm enjoying the result of my discipline, which means enjoying the program as well.
Speaker A
Hearing him say this made me feel pretty optimistic that he was using the best plan.
Speaker A
That is, until the last few weeks of the experiment, where there was one trend I kept noticing from our three-workout group.
Speaker A
I feel way stronger than I did last week.
Speaker A
I'm starting to feel like I'm in my 30s again.
Speaker A
Our three-workout group kept making videos about feeling stronger and lifting heavier than they did the week before.
Speaker A
I think maybe I did push myself harder because I only had three days.
Speaker A
I'm like, we've got to make these count.
Speaker A
We've got to go hard.
Speaker A
We only have three days.
Speaker A
Meanwhile, members of our six-workout group were talking about the training plan as if they were just trying to survive.
Speaker A
Am I enjoying the program so far?
Speaker A
No, I'm not.
Speaker A
I don't know that I would recommend anybody follow this kind of program.
Speaker A
Maybe if I were half my age, it wouldn't be such a big deal.
Speaker A
But feelings don't necessarily tell you which program actually builds more muscle.
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So, after 10 weeks, we collected all of the data, sent it to Dr. Eric Trexler, and let the numbers decide.
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Whenever I analyze data, the first thing I do is just visualize the data.
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I try to get an understanding of the data characteristics and the distributions.
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You're basically trying to make sure that your data collection process yielded data that are high-quality and realistic.
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And looking at the data from this experiment, that was definitely the case.
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The analysis revealed that all of the groups in this experiment did, on average, achieve statistically significant growth.
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Now, the million-dollar question is: which group grew the most?
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Combined growth in the six-day program was 0.83 inches on average, whereas the three-day-a-week push-pull-legs led to a combined growth of 0.75 inches.
Speaker A
Now, you might say, you know, that looks like a meaningful difference, but it's important to understand that that was not nearly a significant difference between the two, and any statistician would look at these data and say those two groups essentially grew the same amount.
Speaker A
So, despite our three-day group doing half the training, statistically they grew pretty much the same as the six-day group.
Speaker A
Now, my first assumption is that we accidentally screwed something up.
Speaker A
The strongest available research out there suggests that if you go from 10 sets per muscle per week to double that, you should get about 60% more gains.
Speaker A
And when I run that calculation, that means the six-day-per-week group should have seen a combined growth of 1.2 inches instead of just 0.83.
Speaker A
In my experience, most people who push to higher frequencies and higher volumes, they end up sacrificing othe
Speaker A
Hello. Oh, hi. What's up, man? Good to see you. How did you like training six times a week? It seemed like you had quite a hard time.
Speaker A
Am I enjoying the program so far? No, I'm not. I feel nauseated. Quite frankly, I I would say that I hate it at that time.
Speaker A
Well, I do have some good news for you. I have another experiment. Oh, wow.
Speaker A
Yeah, sure. I'm in.
Topics:muscle growthtraining frequencypush pull legshypertrophygym workouttraining volumescience-based trainingresistance trainingmuscle building experiment
