and I think Push Pull Legs, for example, I see a use case for, but it's only for those who are consistently training six days a week or more essentially, because otherwise you're missing out typically on training each muscle twice a week.

Folks, Dr. Mike here, from RP Strength, and I'm here with Dr. Milo Wolf, researcher extraordinaire, actually doing research on how to get jacked.

Anything on how to get tan from your lab?

Looking at me, you would think I'd have the keys. Apparently not. On getting jacked, you told me, "Listen, this new meta- analysis came out and it's kind of about how to get jacked in general or training for getting jacked, but it has a few unique features that it also has training frequency recommendations as well as volume." Tell us about the new meta-analysis, what we can learn from it.

Sure, as of this video, when this comes out, there should be a preprint of a meta-analysis on train frequency and muscle hypertrophy. So we're getting the shit early.

Early. Getting exclusive. Exclusive. Essentially, they looked at all the studies that manipulated frequency, having people train a muscle fewer times a week or more times a week, and they looked at how that influenced hypertrophy.

I'm sure you've heard the claim online that certain people say full body training is best, you want to have a full body split, train each muscle as often as possible.

Or back in the day, especially, body part splits were best. Legs Monday, exactly, back Tuesday, shoulders, you get the deal.

This meta-analysis tried to look at that idea and we found a few things. This was a meta-analysis by Pelin and colleagues.

Frequency seems to have a neutral to slightly positive effect on hypertrophy. So, as you volume equated or not volume equated? Okay, correct. So let's just describe to folks quickly what that means.

Volume-equated means if you have to do, let's say, 12 sets per week, you can do them Monday, Wednesday, Friday, four sets, or you can do them Monday, Thursday, six sets each.

Still 12 sets per week. So the frequency doesn't raise the volume, but it just hits you with a little less, a little bit more often.

And what you're saying is the effect is either like, man, nothing to write home about, or like a little bit of a boost, even if the volume doesn't go up.

What do you ascribe that to hypothetically?

I have my own guesses, but I want to hear from you. There's a variety of things mechanistically. Whenever you muscle that growth curve response only lasts so long.

Mhm. So even if you blast a muscle with more and more volume in a single bout, that myofibrillar protein synthesis response, muscle growth essentially, will only take so long, several days.

Correct. Not eight days, not seven days, probably not six or five.

Correct. More like two to three. Correct. So if you're only training a muscle once a week, you're missing out on three or four days out of that week where you're not growing that muscle.

At least neutral. And then you grow it, but again, at least neutral, missed opportunity to get more growth.

Correct. Because essentially what we want to do is maximize that area under the curve of hypertrophy. And so if we're only aggregating one bump, that is only so much area on the curve we could potentially get.

Yeah. So that is my most likely explanation.

To be clear, the effect is somewhere between there is next to none and there's a slight positive effect, slight. So if we want to maximize muscle growth, we probably want to err on the side of training muscle a bit more often rather than a bit less often because there's nothing to be lost, but there is potentially a small thing to be gained.

Train a muscle a little bit more frequently, but with the same volume, 12 for three sessions versus 12 for two sessions.

Six versus four sets in those extra sets on the fewer sessions. At the end, you're kind of a little bit fatigued as the French would say.

And then maybe your stimulus isn't as great as if you were more fresh. So in essence, three days a week of training gives you kind of more rest breaks between the sets on average and the workouts on average, so you can come back fresh and hit it.

Do you think there's maybe some reason to think that a little bit?

It's funny you mention that because I'm aware of an upcoming analysis on the topic of per-session volume and hypertrophy.

Now that is probably not going to be published at the time of this video. If it is, I'll comment it below so you can check it out.

But the relationship between per-session volume in hypertrophy displays more strongly diminishing returns compared to weekly.

Now, as we mentioned in our video on volume, we don't have any studies looking at high-frequency training in conjunction with high-volume training.

Yeah, we don't really have studies where people are training five or six days a week with really high volumes. Most of our studies are on high volumes, but training muscle two or three times a week.

Yeah, we have very few studies on frequencies of like four, five, six times a week per muscle.

However, with a previous analysis by Kreiger, James Kreiger, for example, on per-session volume, and this one that I'm aware of behind the scenes, I can tell you that there is more of a diminishing returns situation with per-session volume and hypertrophy, which with a bit of speculation and a bit of theory crafting, leads me to think practically speaking, if you're training with really high volumes, if we want to maximize that area under the curve, we're better off spreading that high volume across more sessions because we get such strong diminishing returns on a per-session basis.

Yes, and so if you're doing say 20, 30-plus sets for a muscle, fractionally speaking, counting both direct volume and indirect, that is where I think there's a case to be made, as we'll probably see in the meta-analysis by Remon and colleagues, for your volume to be spread out across three or more sessions.

It's just that we don't have the research on that yet to make any super clear inferences, right? All right, so a small increase in growth, potentially neutral to small from added frequency in a volume-constrained manner.

Did they look at unconstrained volume as well? They did not. However, they looked at a variety of potential moderators.

So they performed sub-analyses based on training status, whether they were more untrained or at least slightly trained, whether they were trained to failure, et cetera.

And just like with volume, the relationship between frequency and hypertrophy seems to be robust to different moderators.

So for most populations, in most contexts where you're trained to failure, et cetera, training a muscle a bit more often is going to have a sort of neutral to positive effect.

So I would say as a rough ballpark, train each muscle at least twice a week. Mm-hmm.

That relationship between frequency per week, like how often you train muscle and hypertrophy, you see slightly larger returns when you go from say once, twice a week, then you do after that.

I would say this is kind of an inflection point where after twice a week, there's maybe a positive effect, but it's very minimal.

So, significantly different returns from one to two versus practically, I would say so, practically, I would say that you're better off training each muscle twice a week than once a week.

Past that, it's probably a neutral positive effect, but it's a very slight one. And there is one very So, practically, that means that if you are training two days a week, for example, you're someone who doesn't have much time, you should almost certainly be training with a full body split.

There's no real downside, but there is an upside to training each muscle twice a week or more. Likewise, if you're training, say, four days a week, you're likely better off with something like an upper/lower split compared to like a body part split.

Importantly, here's an interesting part, just like with volume, they looked at frequency fractionally. So, they looked at direct instances of training a muscle, like for example, the biceps, doing bicep curls would be a direct instance.

They looked at indirect instances where, for example, doing back training would still target the biceps, but just not as well.

And they looked at fractional frequency, where essentially they counted direct bicep training as one unit of training frequency for the biceps, and back training as half a unit of training frequency for the biceps.

And once again, just like for volume, fractional frequency was the most accurate way of looking at the data.

Excellent. So, back training still counts for something because it's more realistic.

Correct. It's, it would be a lie to say that 16 sets of back work on a Friday does nothing after a Monday and Wednesday bicep workout doesn't have any more effect on biceps.

It would also be a lie to say that it counts for 16 sets of biceps, that's fucking crazy, but it might for something like 4 to 12.

Yeah, some half there, sure. So that was interesting as well because it means that a body part split can be modified to be pretty effective.

Like, don't get me wrong, training a muscle once a week probably not ideal.

And if I were coaching you, I would say try training at least twice a week, sure. But if you modify it a little bit, say instead of just doing Monday chest, Tuesday back, Wednesday shoulders, Thursday legs, and Friday arms, you add in some compound training for your arm day, you do some chin-ups and do some bench pressing.

Maybe you add some a couple of leg exercises on your shoulder day. All of a sudden, for most muscle groups, fractionally speaking, you're actually training them one and a half or two times a week.

Yes, it doesn't take a lot of modification to make even something a body part split pretty effective with frequency not playing so big of a role in the first place, with it being more so about volume and potentially other factors.

Even the body part split can be effective, but if you want to improve that a little bit, just some small tweaks can take it from effective to quite a bit more effective.

Many people may see this study and as usual, without reading it, will conclude that frequency is not a big deal, neutral effect, maybe a little positive.

But what do you think they're missing, Milo, if they don't include the fact that this was a volume-equated study?

Tell us a story about non-volume-equated frequency that makes some sense. Yeah, so a few things. One, with really high volumes, like we just mentioned, there is a potential use case for higher frequencies.

That is one thing. Equally, I think most people will be able to tolerate more volume and have higher quality volume, quote unquote, if they're doing the same amount of sets with a higher frequency.

So just spread out across the week, better technique, better effort, better follow-through, less likely to slow off on later sets, correct?

It's set number seven of legs, you're like, man, I'll do it, but I'm not going to do it to it, whereas if you take those eight sets, for example, you're doing in one session and spread it into two days, yep, mentally present for each 100%.

So I think with specialization phases where you're performing higher volumes, or if you want to get the most out of each set, a slightly higher frequency can be beneficial.

Look, it's not going to be a 9-day effect, but I think if you want to optimize your growth, slightly higher frequencies are probably a good idea.

It's an optimization thing, but it's also a question of what exactly do you lose by just taking single-bout training and spreading it out more?

I think it's a personal preference thing for a lot of people.

They like to just smash the muscle just a few times a week, or even once. But even for the one time a week, your recommendation is like, okay, fuck it, you like once a week, sweet.

Monday hit chest like crazy, hit a few sets of triceps after, though, and then Thursday hit your tricep workout, your bicep... still say arms Thursday.

Thursday arms, back, shoulders, arms somewhere there. And uh, legs never shows up, but uh, after you finish your bicep stuff and your tricep stuff, do a couple of sets of close-grip presses or push-ups after your triceps.

stuff, it'll cook your triceps even better, but it'll get you enough of a stimulus for chest that it's you're definitely benefiting from multiple per week frequencies, and you'll probably be able to put in a little bit more volume that way and a little bit more of an elevation of the fractional synthetic rate of muscle growth and you'll get more jacked over long term versus Monday chest, Thursday shoulders and arms, but nothing remotely to do with chest at all because it needs recovery, bro, because it probably doesn't training once a week.

I agree. And I think people can think of frequency of training kind of like protein, where total protein intake is fairly important for hypertrophy, and you want to make sure you're getting enough protein each day to maximize hypertrophy, but exactly what your meal frequency is in a given day, like whether you're having three or four meals or four or six or what have you, doesn't seem to play nearly as large of a role.

It's the same with volume and frequency, where volume seems to be quite important for hypertrophy, as we've discussed, but exactly how you spread that out plays potentially a small role, but certainly not as large as volume.

Yes, unless we go to the extremes. Correct. One meal a day, difficult to get your protein at all. Just like one workout a week is how you're going to get all your volume in.

It's practical consideration, but also a lot of the protein that's available to you in the digestive tract from any one meal, some fraction of it gets used for muscle synthesis, not high, and the rest of it the body doesn't need at the time just gets burned directly for energy.

And so you eat 250 grams of protein and one meal, you may find that like you only really utilized 125 of that, which is good, but if you ate 100 grams of protein per meal twice a day, or 125, you may anabolize.

Because I think here's here's where I'm going with this.

Some people are looking, what can I get away with doing the minimum to still get great results? And there's nothing wrong with that, that's great.

But a lot of people are looking for, I want to make sure that my workout routine is checking all the big boxes and not missing out on some shit where it's like, man, I wish I knew that.

You know, like for example, talk to people who try to get bigger shoulders, side delts, and they're training shoulders, their shoulder day is crazy, but it's once a week.

I usually talk to those people and I go, dude, try two or three shoulders per week exercises and or sessions rather.

You're going to see a huge difference because your shoulders just take that long to recover and you can multiply your volume by XYZ.

Those people typically experience that they go, God damn it, why didn't anyone tell me this shit? So as far as frequency per week, we're ready to say you and I, real serious effort at getting jacked, two times a week frequency is the meat and potatoes for most people.

Sometimes higher is better, unlikely that lower is better. Solid take. I think practically for people what that means is if you're training two to three days a week, I would typically stick with a full body approach that allows you to train most muscles two to three times a week.

And real quick, just for folks that don't connect the dots yet, because it took me a while to understand this.

The alternative is people will say, okay, I train Monday, Thursday.

You're okay, great. And you and I are on making think in full body because it takes the growth happens for a few days, it comes down down happens a few days, comes down.

But some people will be like, "Okay, so I do upper body on Thursday, lower body on Monday." And you're like, "Oh, man, the volume is the same total, if the total amount of workouts is the same, but now the frequency is insufficient.

And now you grow a little bit, but then you sort of and you grow a little bit more.

So just the frequency alone, even if it's a smaller effect, and between one and two, it's a notable effect.

It's a good idea to do a 2x or more, even if you just train twice a week. Correct, which means the best routine for you will depend on how often you train, because we want to hit each muscle at least twice a week, sometimes more.

So I think if you're training two to three days a week, all else being equal, a full body routine will be pretty adequate for most people.

If you're training four days a week or five days a week, an upper/lower split could work great.

Full body can work great too, still, for sure, if you're recovering, joints feel okay. But then four to five days a week is where upper/lower starts to become more viable because it allows you to train each muscle twice a week at least.

If you're doing a five-day split, for example, you could do upper, lower, upper, lower, upper.

Yep. Two days for upper body, which anecdotally I enjoy, two days for lower body.

And I think Push, Pull, Legs, for example, I see a use case for, but it's only for those who are consistently training six days a week or more, essentially, because otherwise you're missing out typically on training each muscle twice a week.

For you to train each muscle twice a week, you need two full rotations of the Push, Pull, Legs sequence.

Push, Pull, Legs, Split Is Dead

Renaissance Periodization

🔬 The Latest Science on Training Frequency

Dr. Mike Israetel from Juggernaut Strength and Dr. Milo Wolf, a researcher specializing in hypertrophy, dive into a **new meta-analysis on training frequency and muscle growth**. This pre-print study, by Pelin and colleagues, examines how manipulating training frequency—from fewer to more times a week—impacts hypertrophy. The goal is to understand if popular online claims about full-body vs. body part splits hold up.

The meta-analysis found that frequency has a **neutral to slightly positive effect on hypertrophy**, even when volume is equated. This means that if you're doing, say, 12 sets per week, spreading them across three sessions (4 sets each) instead of two sessions (6 sets each) can offer a small boost, or at least no downside.

📈 Why More Frequent Training Might Be Better

The potential benefit of higher frequency, even with the same volume, likely stems from the **duration of the muscle protein synthesis (MPS) response**. After a muscle is stimulated, the growth response only lasts for about two to three days. If you train a muscle only once a week, you're missing out on several days of potential growth. Spreading out your volume helps maximize the "area under the curve" of hypertrophy over the week.

Another factor is the quality of sets. Spreading volume across more sessions means you're **less fatigued on average during each set**, potentially leading to better technique and effort. This is particularly relevant for higher volumes, where diminishing returns on a per-session basis become more pronounced.

The most significant gains in hypertrophy from increased frequency seem to occur when moving from **training a muscle once a week to twice a week**. After that, the positive effect is minimal. So, a practical recommendation is to **train each muscle at least twice a week**.

Interestingly, the meta-analysis also looked at **fractional frequency**, where indirect muscle stimulation (like biceps working during back training) is also counted. This approach proved most accurate, suggesting that even a body part split can be effective if modified to include compound movements that indirectly stimulate other muscle groups.

💪 Practical Application: Tailoring Your Split

The ideal training split depends on how many days a week you can train. For **two to three days a week**, a full-body split is usually best to ensure each muscle is hit at least twice. For **four to five days a week**, an upper-lower split becomes more viable, still allowing for twice-a-week muscle stimulation.

**Push-pull-legs splits are best reserved for those training six or more days a week** to ensure two full rotations and adequate frequency for each muscle group. Body part splits can still work, but **require smart modifications**—adding compound exercises to ensure muscles are hit at least 1.5 to 2 times fractionally per week.

🎯 Optimizing for High Volume and Specialization

When training with **really high volumes (20-30+ fractional sets per muscle per week) or specializing in a particular muscle group**, higher frequencies can become even more beneficial. Spreading this high volume across three or four sessions helps mitigate diminishing returns on a per-session basis.

A good rule of thumb for per-session volume is **around 5 to 8 direct sets per muscle**. For every 10 fractional sets a week, consider adding an extra training day for that muscle. So, for 20 sets a week, aim for two days; for 20-30 sets, three days is a good ballpark. This allows for optimal muscle stimulation and recovery.

Introduction of New Meta-Analysis on Training Frequency and Muscle Hypertrophy

Dr. Mike Israetel and Dr. Milo Wolf discuss a new meta-analysis concerning training frequency and muscle growth.

The meta-analysis, by Pelin and colleagues, examined studies manipulating training frequency to see its effect on hypertrophy.

Frequency has a neutral to slightly positive effect on hypertrophy, even when volume-equated.

Mechanisms Behind Frequency's Effect on Muscle Growth

Muscle growth response (myofibrillar protein synthesis) only lasts for about two to three days after a training bout.

Training a muscle only once a week means missing out on several days of potential growth.

Higher frequency (e.g., three sessions vs. two for the same volume) allows for fresher performance in each session, potentially leading to better stimulus.

Diminishing Returns of Per-Session Volume

Session volume shows stronger diminishing returns for hypertrophy compared to weekly volume.

For high volumes (20-30+ sets per muscle), spreading the volume across more sessions is beneficial due to diminishing returns per session.

Training each muscle at least twice a week is recommended, as the largest returns are seen when increasing from once to twice a week.

Beyond twice a week, the positive effect is minimal, but there's nothing to lose and a small gain to be made.

Fractional frequency, accounting for both direct and indirect muscle stimulation (e.g., back training targeting biceps), is the most accurate way to assess training frequency.

Optimizing Training with Higher Frequencies and Volume

Higher frequencies can lead to higher quality volume, better technique, effort, and follow-through across sets.

Spreading out volume, even in a body part split, through small modifications (e.g., adding compound exercises on other days) can effectively increase fractional frequency to 1.5 or 2 times a week.

Frequency is like protein intake; total amount is important, but how it's spread out (meal frequency/workout frequency) plays a smaller, but still beneficial role.

Practical Routine Recommendations Based on Training Days

For 2-3 training days a week, a full-body approach is typically best to hit each muscle twice a week.

For 4-5 training days a week, an upper-lower split works well, allowing for at least twice-a-week muscle training.

Push-Pull-Legs (PPL) is suitable for those training 6 or more days a week to ensure each muscle is hit twice.

For specialization or very high volumes (20-30 fractional sets per muscle per week), higher frequencies (3-4 days a week for those muscles) can be beneficial.

A general guideline for optimal hypertrophy suggests limiting direct sets to 5-8 per session per muscle, adding an extra training day for every 10 fractional sets.

Push, Pull, Legs, Split Is Dead

Push, Pull, Legs, Split Is Dead

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