Listen on Apple Podcasts | Listen on Spotify | Listen on YouTube

Rep ranges and muscle building is a controversial topic.

Some people believe that you can maximize muscle building by training with high reps and light weights (<60% of your one-rep max), others believe you should train with low reps and heavier weights (80+% of your one-rep max), and others still believe you should to do both.

Who’s right?

That’s what James Krieger and several other researchers wanted to find out in a meta-analysis that was just published just this year in The Journal of Strength and Conditioning Research.

They combed through 21 different studies that compared how training with heavier or lighter weights affected muscle and strength gains, and in this episode, James is going to break down exactly what they found and how to use it to optimize your programming and ultimately your muscle and strength gain.


5:57 – What is the study on high vs load training and how it impacts strength and hypertrophy?

11:10 – If you’re no longer gaining strength on your key lifts, are you going to get stuck on your size?

24:32 – What are the takeaways?

28:22 – Are there benefits to varying rep ranges?

33:31 – Where can people find you and your work?

What did you think of this episode? Have anything else to share? Let me know in the comments below!


Mike: [00:00:26] Hey, this is Mike from Muscle For Life and Legion Athletics. And as you probably know, I work pretty hard to understand and promote high-quality diet, nutrition, and exercise science. And that’s why I have spent, and continue to spend, quite a bit of my time researching and then writing articles, writing books, recording podcasts, recording videos, and so forth and that’s why I reference quite a bit of scientific literature in all of my work.

Now, something I don’t do, though, is produce a research review where individual studies are broken down and analyzed because: one, my plate is already overflowing with projects as it is, and two, I honestly don’t think that I could do it better than the researchers who are out there creating research reviews and whose work in research reviews I myself read regularly like James Krieger, Eric Helms, Greg Nuckols, Mike Zourdos, Alan Aragón, and Bret Contreras.

And so I had an idea why not get those guys to come on my podcast to discuss various studies that they have analyzed in their reviews and share with us what they’ve learned and how we can use these key takeaways, how we can use the information in those studies to better optimize our diets, exercise routines, supplement regimens, and our overall lifestyle. Well, I reached out to them and they thought it was a great idea and so a monthly series was born.


Mike: [00:02:01] Basically, once a month I’m going to have one of these guys on the show and they’re going to break down a study that they have analyzed in their respective research reviews. And they’re going to explain to us why these studies were conducted, how they were conducted, what the results were, what their interpretations of the results were, and how we can use the information to improve our diets, our training, our supplementation, or in some cases, just the overall quality of our lives.


Mike: [00:02:30] And this one I was particularly pleased with because the rep range and muscle building topic is a controversial one. Theories and speculations have been flying around for some time now. Going back to when I first entered the fitness space five or six years ago. And fortunately, a fair amount of really good research has been done in that time and has provided quite a bit of insight as to how rep ranges really do affect muscle building.

That said, many people still believe that this is a very black and white matter, you know, some people believe that the absolute best way to maximize muscle building is to simply train with higher reps and lighter weights, others believe that the absolute best way for everyone, in all circumstances, is to train with lower reps and heavier weights, and other people believe that everyone should always be doing both, should be periodizing their training with both lighter work and heavier work.


Mike: [00:03:37] So what’s the story, who’s right? Well, that’s what James Krieger and several other researchers wanted to find out when they conducted a meta-analysis that was just published this year in the Journal of Strength and Conditioning Research. As you’ll hear about in this interview, James and his colleagues combed through 21 different studies that compared how training with heavier or lighter weights affected muscle and strength gains. And in this episode, James is going to break down exactly what they found and how you can use it to optimize your programing and ultimately your muscle and strength gain.


Mike : [00:05:43] Hey, James. Welcome back. Welcome back for another research review. I’m excited to listen and learn.


James: [00:05:47] Yeah, thanks for having me.


Mike : [00:05:49] Okay, so today’s topic is going to be high versus low load training and how do these things impact strength and hypertrophy? Yeah, I’m excited to talk about this because, I said this on our last research review – I forgot that they’re being separated in two interviews – last time we talked about frequency, which is kind of a controversial- a lot of people argue about what is best or what is good and bad with frequency and it’s a very similar ongoing debate with intensity.

So is heavy weightlifting better for fewer reps or is lighter weightlifting for more reps better? What study are we going to be looking at today, if you’ll just take it from there, because I know you’ve done a lot of research, you haven’t just looked at this one paper on this, you’ve done a lot of research on this topic and so I’m very curious as to your thoughts.


James: [00:06:35] Yeah. So just recently, my friend Brad Schoenfeld, he’s the lead author on this paper, but I was one of the authors on this paper as well, we did a big meta-analysis basically comparing strengths and hypertrophy adaptations between low and high load resistance training. So what a meta-analysis is, and I know explain this in the last interview, but I’ll explain it again:

A meta-analysis refers to where you take a group of studies and you statistically analyze them as a group to kind of get an idea, “okay, what’s the overall trend among this body of literature that we have?” And meta-analysis can be pretty useful because one study can’t necessarily tell you anything and even two studies can’t necessarily tell you a lot, especially in the field of exercise science because the sample sizes of studies are so small, we’re talking, you know, 10, 20 people in each study, that’s not a whole lot.

But when you start having, you know, let’s say, 8, or 10, or 15 studies, then you can kind of get an idea, “okay, well, what’s the overall trend here? What are most of these studies showing?” And that’s what a meta-analysis can do and so that’s what we did. And what we did is we took this group of studies – we actually found 21 studies that we put in the analysis.

Basically in these studies they had to compare low load training and high load training. So the low load training in this example, we defined as less than or equal to 60 percent one rep max, so for most people, that’s going to be, if you were to do a set to failure, that’s going to be probably at least 20 reps to failure or more.

So you can probably think of it as maybe anywhere from 20 to 40 reps to failure, that’s a fairly high rep set, fairly light load. The other group was, you know, more than 60 percent one rep max and, you know, that’s going to be usually anything less than 20 repetitions, so, you know, 8 to 12, you know, things like that, 12 to 15, you know. It’s going to vary from one exercise to the next but that just kind of gives you a rough idea of: what are we talking about when we’re comparing, let’s say, heavy to light loads?


Mike : [00:08:25] And how high did the load go in terms of percentage of one-rep max?


James: [00:08:28] I’d have to go back and actually look. I don’t remember off the top of my head, I’d actually to go back and look.


Mike : [00:08:33] Like was most of the data in certain rep ranges or … 


James: [00:08:36] Most of the studies didn’t go above, you know, six to eight reps per set. I don’t think anything went heavier than that.


Mike : [00:08:42] Okay. So a little bit higher than the more traditional – like, most strength training programs are more in the, you know, four to six, five to seven, sometimes three to five if it’s a bit more advanced.


James: [00:08:53] Yeah. Yeah. So when we grouped these studies together we analyzed and basically what we found is for hypertrophy, there was no difference in hypertrophy between the two different loading schemes as long as you did your sets to near failure or failure, it didn’t really matter. It didn’t matter whether you were doing 8 to twelve 12 reps to failure or 15 to 18 reps to failure or 20 to 25 reps to failure.

It didn’t matter, your muscle gains were the same. Now for strength, definitely training with higher loads was better and that makes sense, if you think in terms of specificity. So specificity is something that basically refers to: if you want to get good at something, you have to do that thing. You know, in this study, you know, we’re looking at changes in one rep max.

Well, if you want to get stronger at a one-rep max, you’re going to have an easier time doing that if you’re training at or near a one-rep max, which would mean fairly heavy loads. The further away you get from a one-rep max, the less strength effect you’re going to get. You’ll still get a hypertrophy benefit.

You’ll get the same hypertrophy benefit but the strength benefit is there because I think a lot of people don’t understand that strength and size, while they’re related, they’re not exactly the same. You can get stronger without getting bigger and you can also get bigger without necessarily getting stronger. At least I would say in terms of a brute force one rep max type thing.


Mike : [00:10:18] I had Greg on the show, it was several months ago to talk specifically about that. I thought it was a great interview. Just to boil it down, was saying that, “yes, that seems to be very true when you’re new, so like in your first year, you’re going to gain muscle even if you don’t really gain that much strength,” but he said, “as you progress into your immediate and advanced phase, strength and size become more closely correlated so much so that …”

I’m going off of memory here and paraphrasing, so, you know, take this for what it’s worth, “but as you progress in your journey as a natural weightlifter, there’s a point where it does get important to focus on improving your whole-body strength.” Now, of course, you can do other things, and especially depending on what you want to do with your physique and adding volume to muscle groups that you need to bring up, but if I remember correctly, he was saying that, “there is a point probably where if you’re no longer gaining strength on your key lifts with your big muscle groups, you’re probably going to get stuck also in your size.” What are your thoughts on that?


James: [00:11:22] So I would agree with Greg mostly on that. There’s some – maybe some caveats to what I would say. So, number one, the research looking at the impacts, the relationship between strength and size, there are some limitations to it. I guess I’m probably getting a little bit technical here, but a lot of that data is based on what you would call a between-subjects analysis.

So what you do is you take a group of people, you look at their strength gains over, say twelve weeks, you also look at their size gains over 12 weeks, and then you just run a correlation between the two and say, “okay, did the people who got stronger over the 12 weeks, did they also get bigger than the people who didn’t get as strong, right? So that’s a between subjects analysis.

The problem is, that doesn’t necessarily tell you what happens within any particular individual. And unfortunately, there’s been almost no research done within people. There was one study done on untrained people that was a within subjects thing. And just to give you an idea how poorly strength and size are related in newbie’s, in that study that I’m talking about, there was practically almost no relationship between people’s strength gains and their size gains.

I mean, it was pretty amazing. But these were complete newbies, untrained subjects. What was interesting, though, is that there was a little bit more of a relationship for the isolation movements compared to the compound movements. So, for example, I know in the study for a leg press, there was almost no relationship between changes in quad size and changes in leg press performance.


Mike : [00:12:47] Point there, just for people listening, that means that they could essentially not progress. So they could just start with whatever weight and they’ll say, “just do 10 reps,” and then they really never add weight to the leg press, there’s just no real progression, but they still were adding size to their quads.


James: [00:13:02] Or vice versa, they could have gotten significantly stronger, and yet they experience no size gains at all. I mean, so it can work both ways.


Mike : [00:13:11] I mean, that would seem to be a response then, right? Because like, if one person can gain size without progressing and another person really doesn’t gain any sized progressing, they definitely would not have gained size not progressing [laughter]


Mike : [00:13:23] Yeah. Yeah.


Mike : [00:13:25] And again, that’s out there, right, in the literature, some people just respond very well to weightlifting and some people don’t, even if they do everything right.


James: [00:13:32] Oh yeah, exactly. I mean, there’s – Bret Contreras and I wrote an article about this a while back, about individual responses to training because a lot of research just looks at averages, right? But averages don’t tell you what happens in any individual. What’s interesting is when you look at some of these resistance training studies, you see a wide spectrum among people on how they respond to the exact same program.

There was one study where most people experienced, I’d say probably a five percent increase in muscle thickness. But there were a few people that had up to like 15 to 20 percent increases for the exact same training program. And then there were a few people who had no increase at all or even actually had a slight decrease, although that may have just been, you know, random error, in the ultrasound that they were using, but it just shows some people just have – I mean, it really comes down to genetics. Some people just have much better genetic responses to resistance training than others and some people got really unlucky with the genetic lottery.


Mike : [00:14:25] So I would just add, for anybody out there, that has experienced that, and I guess I’m speaking now from working with a lot of people, even people that are genetic, low responders, you can still build muscle, you can still get a great physique, you’re just gonna have to work harder for it than some people. That’s just what it comes down to.


James: [00:14:40] Yeah. Oh, yeah, totally. And there are some people that will just put on muscle no matter … [laughter]


Mike : [00:14:46] Yeah, they can just do push ups every day and then they look great and you’re like, “okay.” [Laughing]


James: [00:14:51] And then some people, no matter how hard you try – I mean, you’ll definitely get a better physique and a great physique, but you won’t necessarily be, let’s say, a top natural level competitor. You know what I’m saying? I mean, some people are just, you know – I think of somebody like Jeff Nippard, for example, the guy, he’s super knowledgeable, very smart about training and everything, he’s really knowledgeable.

But I will say the thing about Jeff, though, and he’ll tell you this as well, he’s also very genetically gifted and anyone who’s seen pictures of Jeff’s mom will know where the genetic gift comes from because his mom is totally jacked [laughing] So he inherited pretty good muscle-building genes from his mother.


Mike : [00:15:29] I think he’s also very short as well, right? I mean, that just plays …


James: [00:15:33] Yeah, he’s very short. Looks like, he’s kind of like a tank, you know, like …


Mike : [00:15:37] I don’t his height I just see the pictures, I’m like, “this dude’s very short,” which also means that you put a pound of muscle on him, visually looks different than somebody who – I mean, I’m not super tall, but I’m 6’2, there’s a big difference there, and that also probably helps him with certain lifts as well, just because of how his body is built. Some people’s bodies also, just because of their muscle insertions and anatomically, they were built to be strong weightlifters [laughing].


James: [00:16:03] Oh, yeah, some people, like – my friend Dean Somerset, is great on this because, like, he’s done a great presentation on – I’ll talk about squats, for example. You know, everyone will say, “oh, you got to squat to at least parallel or lower.” And what people that say that don’t understand is some people, no matter what you do, will never be able to squat to parallel because of their structure, and actually, Dean gives a great presentation on this where he’ll actually show bone structures.

Some people’s bone structures will prevent them from ever being able to squat, even down to parallel. It’s actually impossible for them to do it. So, yeah, people need to understand that there’s just big genetic differences between people when it comes to lifting and things like that. Some people are just built much better to do certain things than other people are.


Mike : [00:16:48] Totally. All right, so, yeah, anyway, I don’t want to completely derail, but I thought it’d be a worthwhile tangent. So getting back to – you were discussing the study, we had untrained …


James: [00:16:58] Yeah. So, yeah, the leg press didn’t really relate to – the size and strength gains, didn’t really relate to each other, but there was a little bit of a relationship for leg extension. It was a weak relationship, it was something like – it’s called an R squared value, which just kind of tells you the percentage variance that can be attributed between the two variables.

The R squared was something like 30 percent, which means 30 percent of the gains in strength in leg extension performance could be explained by changes in muscle size, that’s a fairly weak correlation, but it’s certainly better than, you know, zero. And what that would tell you, at least in untrained people, changes in performance in probably isolation movements are going to correlate a little bit better with changes in muscle size than changes in compound movements.

And that’s because, you think about it, there’s a lot of skill involved in compound movements. And you can get better at a compound movement just by improving your technique and things like that, and that’s especially true with newbies.


Mike : [00:17:54] Yeah, it’s not so much like your body actually isn’t having – from the standpoint of its musculature, there’s not that much adaptation that needs to occur because, I mean, look at when new people start squatting, understandingly so, they start out carefully, so that’s usually very lightweight for anywhere near close to failure.

And then, okay, so they worked their way into heavier weights and then they have that skill component, which is probably, at least for the first few months, you are getting significantly better at the movement and so you’re able to progress, but not so much for any other reason other than you’re just starting – it’s like learning to throw football, you’re grooving in this motor pattern and you’re getting better at it. Yeah, that makes sense.


James: [00:18:36] Yeah, but to add onto the caveat, I guess I would say to what Greg said, it definitely is true, the more trained someone becomes, the tighter the relationship between strength gains and muscle gains become. The one caveat I will add to that is that you want to see performance increases in the rep range that you typically train in.

And the reason I say that is there was one study that was published where they had one group train, the typical eight to twelve rep range, another group trained, you know, 20 to 30 rep range to failure and they compared muscle size gains. Muscle size gains were the same. The group, the trained eight to twelve reps, they saw significant improvement in their one-rep max performance.

The group that trained 20 to 30 reps to failure saw no improvement at all in their one-rep max performance, even though they got just as big. So there’s a certain specificity, though. Now, I guarantee you, if you did, let’s say there are 20 rep max performance, you would have seen a bigger increase in 20 rep max performance for the 20 to 30 rep group versus the eight to twelve group.

So there’s definitely a specificity. So I guess the thing I would add on to what Greg has said is: there definitely is a much tighter relationship between performance gains and size gains the more well-trained you become, but that’s also specific to the rep range you train in. So if you typically train in the 20 to 30 rep range, well, I wouldn’t worry about whether your one-rep max is improving because that’s not going to be indicative of your size gains. But you do want to worry about: is your 20 to 30 rep max improving? That should be improving.


Mike : [00:20:05] That makes sense. Yeah, and then again, I don’t want to oversimplify what Greg was saying, but I just want to get your thoughts on that basic – because I’ve experienced that. And I guess my experience of it is exactly what you’re talking about, actually, because I haven’t done a one-rep max or two rep max test in a while, and I actually don’t really do rep max tests very often, I more just work off of my working sets and so I’ve found what you just said to be true, that:

If there are periods where I was not progressing, even going back to the double progression that you spoke about in the previous research review, where if I don’t really see – I’m not really gaining reps and I’m not able to turn that – leverage that into putting weight on the bar over an extended period time, not much is changing in my measurements or in my in my body.

And where things have changed the most were during the periods, and this was – I joke about it, I had a good run, now that I look back, you know, in my mid-20s before I had kids and more and more work responsibilities and blah, blah, blah, where I was able to put a little bit more time into my training, and also my recovery was better because I was younger and so I had a nice.

I want to say four years or so where I was just able to make just – using that simple double progression model, just consistent, steady progress on all of my big lifts and really also my isolation movements and it was during that period that I saw the most dramatic improvements in my physique and since then progress has slowed for reasons really I just gave.

And I’ve seen now for stretches where if I’m not able to – and sometimes I have to accept it, I’m sure you’ve run into this where simply because of life, like if I’m not sleeping all that well, you know, kids or work or whatever, that I have to accept that, like, I’m kind of stuck right now, but I understand why.

And then I’ve been able to, when things are going smoothly, breakthrough and make some progression again, and see improvements. But again, that’s just my experience, where I’ve tried to get around what you just said by adding volume simply in terms of, okay, I could do extra sets of extra exercises and I could try to, you know, make my workouts harder, but that, for me has not produced the results that progressing in my given rep ranges has.


James: [00:22:24] Yeah. And I’ll actually also add to that, too, you know, you mentioned progressing in the big compound lifts and stuff like that, and you mentioned isolation movements, it’d be interesting, I actually I want to see more data on this, like I said, there’s only one study and that one study at least would suggest that, to me, intuitively, it makes sense.

Perhaps progression on isolation movements may actually correlate a little bit better with the size gains, at least in the muscle that you’re isolating versus a compound movement. And that makes sense, I mean, it’s like, you know, if you’re trying to get bigger quads, your leg extensions should be improving. If you’re squat’s improving, but your leg extensions aren’t chances are you’re probably getting bigger in other places that are responsible for the squat improvement, you know, and not necessarily due to bigger quads, so that would be an example as well.


Mike : [00:23:10] I think a perfect example of that – I mean, some people, I think it depends, right? Because the quads are obviously heavily involved in the squat, and I’ve worked with people that, that’s all they ever needed, guys and also girls, it was squatting and that gave them the quads they wanted and that was it. They didn’t even have to worry about – just straight back swatting, that’s all they needed.

But I’ll say it’s very rare for me – I can’t even – no one even comes to mind, but I don’t know, I think my inbox is over 100,000 emails now from back and forth conversations, so I’ll be surprised if I could go find someone, a guy who, for example, didn’t need to – not just do work for his biceps, but actually progress and get pretty strong on the bicep curl to get the biceps that he wants.

Same thing with shoulders, right? With like side and rear raises. I’ve worked with a lot of guys who have done just pressing and were disappointed with the overall development of their shoulders. And I’ve experienced this as well, where like to get anywhere with my shoulders, I had to get pretty strong on side raises. To get anywhere with my arms, I had to get pretty strong on barbell curl, and like a close grip bench press, or a pushdown, for example.


James: [00:24:17] Yeah, definitely.


Mike : [00:25:49] I guess what we should do, actually, is talk a little practical, like okay so what are the practical takeaways here, huh?


James : [00:25:55] Yeah, that was good that you mentioned that because I was just going to mention like: there is a certain practical thing that you have to be aware of when it comes to this. So number one, this is great because it means that rep range doesn’t really matter all that much.

You know, whether you’re training 8 to 12 reps, 12 to 15, 20 to 25, as long as you’re training to failure – and the caveat to that is: as long as you’re training to failure or near failure, if you’re training well short of failure, then especially with the higher reps, then it’s not going to work. It’s especially important with the lighter weights because of the way muscle fiber recruitment works and everything, the only way lighter weights are going to work for muscle size is: you got to get, you know, close to failure or to failure.


Mike : [00:26:38] I’m sure you’re familiar with this research and we’ve all – I’ve experienced it, you’ve probably experienced it, people listening have probably experienced it, that when you train in higher rep ranges, it gets harder and particularly true in new people, right? It’s harder to predict how many reps you really have left because there’s so much burning, you’re just in pain.

You’re like, “do I want to stop because I’m just on fire,” or is it, “am I actually getting to the point where it’s failure?” Yeah, so anyways, I just want to throw that out there just for people to keep that in mind.


James : [00:27:05] Yeah, and it’s good that you bring that up because it does mean that, while higher reps are great, and it’s especially great for, let’s say, older guys like me who are having joint issues or things like that, the lighter weights are much easier on your joints. You know, it’s funny, in my own training now, I typically don’t do anything less than 12 reps per set, it’s just way easier on my joints.

I have some stuff where I’ll do, you know, maybe in the 20 to 25 rep range, so. But the problem with the 20 to 25 rep range to failure, it’s not really necessary conducive to all exercises, so …


Mike : [00:27:34] Good luck, 25 rep squat [laughing].


James : [00:27:36] Yeah 25 reps squat to failure or 25 rep deadlift to failure, that’s not even necessary safe. So there’s some exercise that you just – either you can’t do it because it’s not safe or as you mentioned, it’s so painful that it’s too hard for someone even to push themselves hard enough. Like, you know, 20 rep bicep … 


Mike : [00:27:51] And to keep showing up every week to want to keep doing it. I mean, if you hate your workouts, that’s not a good place to be.


James : [00:27:58] Well, yeah, and that’s the thing. Like, you know, 20 rep bicep curls to failure, that’s not a big deal, I mean, I can do those – you know, I mean, yea, it burns and stuff but it’s not something that I dread doing, you know. But definitely, if I had to come to the gym and do a 25 rep squat to failure, every time I was training legs, I’d probably start dreading my leg workouts after a period of time, so …


Mike : [00:28:18] I think that’s one the reasons why leg training has gotten like – so many people skip leg days is because – I mean, again, I guess I can’t say I don’t know exactly these days, but back before I tried to even educated myself and I would just do bodybuilding magazine workouts, I mean, 10 by 10 squats was like a thing, like that’s what you did.


James : [00:28:36] Oh yeah. [Laughing]


Mike : [00:28:37] 10 by 10, I’ve done it many times and I hated it. I still go do it just on principle, but eventually, I was like, “okay, there’s gotta be another way. This is the worst shit ever.” Is there anything that, again, this is maybe just my bias toward strength training because I like it [laughing], but do you think that there’s a potential benefit over the long term to at least including some heavier – because of the potential, more importance or correlation between strength and size.

That if you’re going to gain strength faster, obviously with heavier weights, at least in my experience, for whatever reason, it’s been easier for me to progress, just in the sense of gaining reps over time and being able to turn that over into weight on the bar, it’s been easier for me to do that with heavier weightlifting, and I’m thinking more with my compound movements.

I mean, I think where your curls, and your raises, and stuff, and triceps pushdowns less important, but with the compound lifts in particular, it’s been easier for me to progress in the 4 to 6, or 5 to 7 rep range than higher rep ranges, which is what I was doing previously. Do you have any thoughts on that?


James : [00:29:50] Yeah, so if you look at the research on varying rep ranges, I’m actually in my research review, I have an entire evidence-based guide on varying rep ranges. You know, so if you just think of it in terms of – theoretically, you would think, “okay, there might be a possible benefit to varying rep ranges because you train a lower rep range, it enhances strength gains, which should then, when you switch to a higher rep range …” 


Mike : [00:30:12] Kind of “upgrade”, right? “You can then perform even better in your higher up range,” is the idea, at least.


James : [00:30:18] Theoretically that should be true. And then also vice versa, if you train in the higher rep ranges, that should improve your recovery ability so you can handle more volume, let’s say when you train in your rep ranges. So theoretically there’s a hypothetical benefit to it. I will say it hasn’t necessarily panned out in the research.

But you know, one limitation of research studies is they typically only last eight to twelve weeks. So actually, I’ll go back to that study I mentioned earlier where they had – they actually three groups of people in that study. They had one group that trained, I think, 8 to 12 reps, another group that trained 20 to 30 reps, and then they had a third group that alternated every two weeks.

They did 8 to 12 reps for two weeks, 20 to 30 reps for two weeks and alternated. And what they found is there wasn’t any difference between the groups. I think it was only an eight-week study. There was a study that I ran the stats for, for Brad, that Brad published, addresses the similar question. So we had two groups, we had one group that just did straight eight to twelve reps the entire study.

And I think it was an 8 or 10-week study, I don’t remember. Another group varied the repetition ranges over the week, so it was a whole body program but Monday they did, you know, 3 to 5 reps, Wednesday they did 8 to 12 reps, Friday they did like 20 to 30 reps, so they varied the repetition range. Statistically, there was no difference in the gains between the groups.

Some of the effect sizes favored the varied group, I talked about this in my research review, but if you looked at the individual data plots, it’s really just because there were a few outliers in that group, so not really all that convincing, so I’d say the data doesn’t necessarily support it, but on limit of that data is, you’re talking, you know, three-month studies here, it’s very possible that over a much longer period of time, perhaps it’ll make a difference, so…


Mike : [00:32:01] Yeah, there was something in one of the issues of Mass, actually, on a review of DUP, and the long story short, if I remember correctly, is: in high-level strength training athletes there was a slight benefit to varying rep ranges, but it wouldn’t mean much to the average weightlifter, basically. [Laughing]


James : [00:32:20] Now let’s say there is no benefit to it. Even if there is no benefit to it from, let’s say, a hypertrophy standpoint, I would say there’s probably benefits to it from other standpoints. I think there’s a benefit just from a psychological interest, I mean, I think a lot of people might get bored with doing the same rep range all the time.


Mike : [00:32:38] And also, I mean, I don’t know about you, but I genuinely like workouts. I like lifting heavier weight, more than lighter weight. Like, I enjoy those workouts more. I still do both, but I enjoy the heavier training more.


James : [00:32:49] And that’s actually an important thing I think people don’t consider enough, I mean, you could have the most optimal training program in the world, but if you don’t like it and you don’t really want to adhere to it, well, it’s not going to matter, you know, so…


Mike : [00:33:02] I would also question – I would wonder if simply liking your workout and looking forward to it, if that has performance effects that you may not be aware of. That you’re going to give a little bit more in those workouts and you are going to progress a little bit faster simply because you’re more into it, as opposed to just like, you know, going through the motions, doing what you need to do so you can leave.


James : [00:33:24] Yeah, I would agree that there may be a benefit to that, and in fact, I think there was a study that kind of related to that a little bit, but I honestly don’t know for sure, so I vaguely remember a study that was out not too long ago, where I think they had people, I think self select a training program or something like that, I don’t remember exactly, but it sounded like the people that kind of self-selected their training program did better than the people that didn’t.

This is just vague memory I have, but that we would tend to hint to the idea that a training program you like, you may just get better gains just on that alone just because you are more motivated psychologically when you’re there and things like that. So there’s a benefit there, and also, I also want to say, another benefit to varying your rep ranges may be from a joint health perspective.

So I would say, I mean, if you’re training heavy all the time, you might be able to get away with that if you’re in your 20s and even in your 30s, but you’re not going to get away with it once you get in your 40s and beyond. So I think just from a joint health perspective, there’s a benefit towards varying your repetition range, which, you know, if you stay injury-free, it’s going to allow you to train more consistently, which in it of itself, being able to train consistently is going to be one of the most important things when it comes to gains, so…


Mike : [00:34:42] Absolutely, I totally agree. Makes sense. I think that’s everything, huh?


James : [00:34:45] Yeah, I think so, yeah.


Mike : [00:34:47] Awesome. Well, let’s just wrap up with, if you want to let everybody know where they can find you and your work and also, let’s tell them about your research review.


James : [00:34:55] Yeah. Yeah. Yeah. So you go to my website: Got lots of stuff on there, I got a lot of free content articles, a lot of podcasts I’ve been on, speaking events coming up. I’m going to be speaking in the UK here at the end of the month and also.

If you have any Australian listeners, I’ll be speaking in Australia in Melbourne, end of June, and there are actually going be a lot of other great speakers at that event: Alan Aragón, Eric Helms, some other people are gonna be there, Layne Norton, bunch of there people are going to be there as well. So yeah, you can find out that information.

All my social media accounts are on there if you want to follow me. You can find a list of all the research that I’ve published if you’re interested in that. And then, yeah, so I have a research review and some monthly subscriptions. And basically I cover a lot of the latest research in anything that deals with muscle gain or fat loss.

And I cover both new research and older research as well because I think it’s important to cover older research. I think sometimes older studies tend to get forgotten but studies don’t have expiration dates on them.


Mike : [00:35:58] Or shunned. I mean, it’s stupid, obviously, but I’ve had people use that as like a retort like, “oh, that study was published in 1999,” as if we should just dismiss it out of hand because it’s like, “what are you talking about, dude?”


James : [00:36:12] Yeah. The age of the study doesn’t matter unless – the only time it’s gonna matter is if, for some reason, the study used an outdated methodology and things have improved, right? 


Mike : [00:36:22] Things have materially changed since then.


James : [00:36:24] Yeah. But if it hasn’t materially changed, then, you know, just because the study’s old doesn’t invalidate it at all. So yeah, I cover a lot of stuff on there, I also have I an “Ask James” section, where members can ask me questions and I’ll do the research for them.

So the PubMed digging if I don’t know the answers already, answer the questions, and so yeah, a lot of little great features, a lot of the content is video content, so it’s not just written research reviews, but I’ll do actual video, recorded video presentations on some of these studies and things like that. So, you know, for people interested in checking that out, yeah, they could take a look at it.


Mike : [00:36:59] Well, thanks for taking the time, James. Really appreciate it. And again, everybody listening, go over to and check out James’s work. If you like my work, you will like his work, I guarantee you.


James : [00:37:09] Yeah, thanks for having me, really appreciate it.

View Complete Transcript