Everything you’ve been told about doing more sets to build muscle is wrong. 

Amy Hudson and Dr. James Fisher discuss the science behind single-set versus multiple-set training and what actually drives real strength and muscle growth. They break down a review paper comparing one set to three sets and share what the data says about hypertrophy and why effort matters more than volume.

Tune in to hear why more isn’t always better, how supervision changes outcomes, and how you can build muscle in far less time than you think.

• Dr. Fisher breaks down a review paper comparing one set versus three sets for muscle growth and strength. 
• Dr. Fisher covers how effort changes across multiple sets when rest periods are involved. He reveals that sometimes it takes several sets to reach the same fiber recruitment that one high-effort set can achieve. The real driver isn’t volume alone, but intensity and muscle fiber stimulation.
• Dr. Fisher reveals that strength increased to virtually the same degree in both the single-set and three-set groups. Whether participants trained one set twice per week or three sets twice per week, the outcome was the same.
• Why muscle size didn’t differ between one set and three sets. The study showed equal increases in hypertrophy regardless of volume. One properly executed set to a high degree of effort was just as effective as doing three normal sets.
• How beginners can build muscle with just one set is one of the most encouraging findings. Participants with no previous strength training experience saw measurable gains in just 12 weeks. Even one set per exercise, twice per week, was enough to stimulate growth.
• Dr. Fisher explains that this study aligns with a large body of previous research. One weekly set per session was comparable to six total weekly sets in outcomes. That makes single-set training dramatically more time-efficient.
• Amy explains that when you load muscles effectively and train with proper intensity, one set can deliver the stimulus you’re looking for. The key isn’t endless volume; It’s focused, high-quality effort.
• Dr. Fisher highlights the importance of supervision in the gym. Many strength studies showing impressive gains are conducted under close guidance. Supervised training consistently outperforms unsupervised workouts.
• Why personal training dramatically improves results comes down to accountability and execution. Most people lack the consistency, form, and technical precision required to train effectively alone. A coach removes guesswork and ensures every set counts.
• Amy reveals why personal training solves the motivation problem. Around 80% of people struggle with long-term discipline in the gym. Having structured guidance keeps progress steady without relying on willpower alone.
• Dr. Fisher further explains why having a personal trainer benefits even experienced lifters. 
• How to achieve maximum results in minimal time is the core takeaway from this episode. According to Amy, one well-executed set, performed under proper guidance, can stimulate strength and muscle growth effectively.

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You know, they’re effectively saying you can increase strength and muscle size in a matter of minutes.

When you work out effectively and that short amount of time that it takes to do that one set can achieve the benefits that you’re looking for in so much less time.

Even one set per exercise can start to show muscle size increases.

Welcome to the Strength Changes Everything podcast, where we introduce you to the information, latest research and tools that will enable you to live a strong, healthy life. On this podcast, we will also answer your questions about strength, health, and well -being. I’m Amy Hudson. I own and operate three exercise coach studios. My co -hosts are Brian Sagan, co -founder and CEO of The Exercise Coach, and Dr. James Fisher, leading researcher in evidence -based strength training. And now for today’s episode.

Welcome back to the Strength Changes Everything podcast. Today’s episode is a research review. Every so often on the podcast, Dr. Fisher comes prepared with a study or research that he’s come across that we will break down and review here together live with you on the podcast. You may remember the previous episode we did on how to spot reliable fitness advice online. And in that episode, we taught you how to evaluate claims that you come across and read a, perhaps, review and understand the limitations of that review, perhaps, or how it was set up in order to to assess it properly and perhaps come to the right conclusions when you’re looking at things. And so today’s episode is all about a particular research review that we’re going to cover.

And it is on the topic of basically multiple set versus single set exercise. And again, if you may recall, we’ve done another episode on that same topic as well, single set versus multiple set and the size principle. If you missed that episode, go back and listen to that. So today’s episode is kind of meshing together a couple of different previous episodes. And so, Dr. Fisher, you know, I want to start off. My first question for you is, what is the study that we’re looking at today and how is, you know, the discussion that we’re about to have similar to or going to expand upon the other episode we’ve already done on the size principle and single set versus multiple sets.

Thanks, Amy.

Yeah.

So to be honest, this queues up nicely, those previous podcasts that you just mentioned, the idea of trying to understand research and trying to understand kind of scientific principles and so forth. And also, like you said, the single versus multiple set concept that we discussed in the size principle. So we’ve got a research paper here that’s basically looked at exactly this. I’ve got the title on the screen for anybody watching on YouTube, but for anybody listening, it’s a 2025. It’s actually e -published ahead of print, so it’s actually not gone into print yet in the Journal of Strength and Conditioning Research. It’s been published on their website, but it’s not gone into their print version yet, so it’s brand new.

And the title is pectoralis clavicular and sternocostal thicknesses increase similarly in response to one and three sets of pec deck resistance training in untrained young men. And there’s a bit to unpack in the title there itself, which we will do. But fundamentally what this is saying is how does muscle growth differ or is it similar between performing one set or three sets of an exercise in, as it said, untrained young men? So this is exactly what we talked about previously. We talked about some of the mechanisms associated with resistance training and the size principle and effort and muscle fiber recruitment. And one of the things that we said is,

when you do three sets of an exercise you maybe rest between sets and you maybe don’t reach the same intensity of effort or it takes multiple sets to reach the same level of effort and reach the same stimulus for recruitment of muscle fibers to promote the same muscle growth or muscle strength increases. And so this is a study that’s done exactly this. It’s compared one set and three sets for this particular exercise.

All right.

I’m excited to hear what it says.

Yeah.

Okay. So the first thing that I wanted to do is, as it said in the title, is pectoralis clavicular and sternocostal thicknesses. So I wanted to just clarify that because many people, we’re going to use this as an example, kind of in relation to what we talked about previously, about how to maybe understand research. So, you know, many people will go to the title of a study, and there’s a few things, like I said, to unpack. So the clavicular and the sternocostal heads of the pectoralis major. So I’ve shown an image on the screen, and our pectoralis is our chest muscle, so it’s in the upper part of our torso, our anterior torso, so the front.

Most people will know where their chest is, hopefully. And the pectoralis pectoralis major can be split into two heads, the clavicular head, which attaches to our clavicle and runs out to our humerus and the sternocostal head, which attaches to our sternum, which is basically our kind of our breastbone down the middle, and also runs out to attach to our humerus. And the primary role of these heads of the pectorals is what’s called horizontal adduction. of the humerus. So if you lift your arm up to 90 degrees out in front of you, and I’m doing this for everybody watching on YouTube because I can’t help but do it as I talk through it, if you lift your arm up to 90 degrees in front of you and you abduct it to the side, so it’s basically right out by your side, then it’s your chest muscles that will bring it back in line with your torso.

So when it’s out to the side, it’s your pectorals that will pull your arm horizontally back in front of your body. And most people, if you put your hand up by your clavicle, you can feel that muscle kind of doing some work there to perform that action. So those are the two heads of the pectoral muscle they looked at in this study. So we’ll get into a few of the details now. So it was a within -participant design. So a within -participant design means that each participant was in both conditions.

And this is a really nice design because it controls for nutrition, it controls for sleep, and it controls for genetics. So what all of this means is that one arm did the one set, and the other arm did the three sets. So one side of the chest got only one set stimulus and the other side of the chest got three sets stimulus. Okay now we could ask what if there was a difference between the dominant arm and the non -dominant arm and they controlled for that. So seven people uh had their dominant arm in the three set group and eight people had their dominant arm in the single set group so they kind of tried to counterbalance that effect they also did two pre -intervention tests so anytime you’re measuring muscle growth it’s nice to establish a clear baseline now these were untrained participants so untrained basically means they weren’t engaged in a structured resistance training program. But it’s also good that one week apart, they measured the muscle size of each head of the pectoral muscles so that they knew that it hadn’t changed.

They knew that it was stable. They knew that it wasn’t going to vary on a normal day -to -day basis. And then they measured it again at week six, which is halfway through the study. And they measured it again at week 13, which was at the end of the study. So they had multiple time points, which is really nice. You know, these are all kind of benefits of the, of their research design.

They controlled repetition duration. They said the rep duration was about two seconds concentric, two seconds for the shortening of the muscle or the lifting of the weight. And then two seconds eccentric for two seconds for the lengthening of the muscle or for the lowering of the weight. Resistance training was performed twice per week for 12 weeks on non -consecutive days. So they said there was about 48 hours between workouts, which is quite typical. And this, of course, aligns really well with exactly what we do with the exercise coach training twice per week on non -consecutive days.

So it’s a really nice, clear study design. And they also use progressive loading. So they were using a selectorized weight stack resistance machine, PECDEC resistance machine. And they said that in weeks one to two, they used a weight that equated to between 18 and 20 rep maximum. And that progressed up to a weight that was equivalent to about eight to 10 repetition maximum. for the final couple of weeks.

So there’s a progressive increase throughout that 12 week period. Again, if you’re watching on YouTube, you can see this on the screen, the exact progression. But what this basically meant was that the weight increased every couple of weeks, but the time under load decreased every couple of weeks as well. So it went from about 80 seconds in the first couple of weeks down to between 30 and 40 seconds in the last two weeks. So they basically just ramped the weight up over this 12 week period. And then one of the really important things that they clarified was that all the resistance training sessions were supervised by two researchers.

in fact they clarified that one person gave motivation and encouragement and coaching and the other person helped the participant to be stable within the seat. Because when you do a pec deck exercise, if you only do one arm, there’s quite a tendency for our body to maybe twist. So they helped hold the rest of the torso nice and straight, as well as other restraints that they used to do that. And they also clarified that adherence was 100%. So all participants attended all resistance training sessions. So again, really important, as you can imagine.

Okay, so what did they find? So first of all, they also measured strength, they measured one repetition maximum. And we can see on the figures, again, if you’re watching on YouTube, you can see on the figures, there’s our pre -test pre -test one, pre -test two, and there’s our po -test week 12. And each of the dots actually represent each individual person within the study as well. Oh, we can see that strength increased to effectively the same proportion between both the one set and the three set conditions. There’s no difference in strength change, whether they did one set twice per week or whether they did three sets twice per week.

But more importantly, and what the study was primarily interested in was muscle size increases. So we’ve got the figure on the screen again. We’ve got one set on the left side and three sets down the right side. And then the clavicular head is across the top and the sternocostal head is across the bottom. And again, basically what we can see is that there was muscle growth from baseline to week six, and then again from week six to week 12. And that was for all.

uh for both muscles for both the clavicular and the sternocostal head of the pectorals and also for the one set and the three set group with effective no difference between any of them. So, it didn’t matter if you were doing one set or three sets, you got the same increases in muscle size. Now, obviously this is really important and this aligns with the evidence -based philosophy of the exercise coach that we just do a single set of an exercise to a high degree of effort because that stimulates all the muscle fibers to adapt and prompts strength and muscle size increases as effectively as three sets, but this study proves the point perfectly. So we can now skip back to their abstract. And this is what many people who first engage in research will look at.

And I’ve highlighted a few key things. So they go on to say, or they clarify in the abstract that they used 15 untrained young men, age 24 years, a mean age of 24 years. So first of all, this is a population group that you would expect to see muscle size increases. They’re at what I’ve often referred to as an anabolic stage in their life. They’re still in a very much a building phase so they are probably going to find it easier to build muscle than somebody maybe in their 30s or in their 40s or 50s or so forth. So the muscle size increases they make might not be the same as the muscle size increases that somebody might expect at a different time and so forth.

One of the reasons why many resistance training studies have untrained young men of this age group is because they tend to be the people that are most accessible in a sports science laboratory or in a sports science gym environment. So there’s kind of a convenience element to that. It’s not necessarily that they’re the most important population group to look at. It’s just a convenience attached to that. They’re then going to say that they use b -mode ultrasound so that was simply the method of measurement for the for the measurement of muscle thickness.

And then they of course said the pectoralis major clavicular sternocostal heads. And then they clarify the results that after 12 weeks of resistance training, pectoralis major at the clavicular head for the single set was 17 % and for the three sets was 18%. But at the sternocostal heads, it was around 21 % increase for both one set and three sets. So no differences between the two conditions. They also clarify that maximum strength increased by 46 % in the one -set group and by 43 % in the three -set group, but we really shouldn’t read much into that small difference. That’s effectively the same increase between the two conditions.

So the final thing that I always encourage people to, to look at when they’re engaging in a research study. And I really want to really, you know, we spoke for the podcast and I said, I wanted to make a point of discussing this is no research is perfect. There are always going to be some limitations to research. And so we should clarify those. So it was a relatively small sample size. They only had 15 participants in the whole study.

So. Yes, we can look at the data and say, okay, they used a really nice within participant research design, but it was only 15 people. If they’d used 150 people, then we could take more confidence in the study. If they’d used 1 ,500 people, again, we might have that been more confidence in the study. So 15 people is a relatively small sample, but it’s also quite typical of this kind of resistance training study. Now they used a within -participant design and we’ve talked about the benefits of this in the form of controlling finition.

controlling for sleep, controlling for genetics, controlling for all those other biological factors. But on the podcast previously we’ve also talked about something called contralateral adaptations and that is if you train one side of the body you might or you often see adaptations on the other side of the body. So in this case, if one side of the body did one set and one side of the body did three sets, it could be argued that the stimulus effectively combined and hence we saw the same adaptations on both sides of the body. So it’s just something to bear in mind. The authors actually go into detail about why they don’t think that was the case, but it would be Fair to say that that’s a possible limitation of the study. And in fact, what would be really nice would be a within participant design with a third group where, um, they didn’t do any resistance training at all.

So you can imagine if some people did three sets on one side of the body and the other side of the body did nothing, and some people did one set on one side of the body and the other side of the body did nothing, well then we would be able to see if there was any crossover or contralateral adaptations to that untrained side of the body. But that’s, again, a problem with research. It’s very expensive, it’s harder to recruit a larger sample size, and so forth. So it’s just simply not something that they did with this study. We could also look at this and say, this was a 12 -week resistance training intervention, and 12 weeks isn’t a long time. Now, for many people, going and doing strength training for three months might feel like a long time, but actually, in the grand scheme of things, it’s not a long time.

If we’d seen a difference in, in 12 weeks of resistance training. I personally would argue that, well, would that difference still exist at six months or at one year and so forth? So the fact that they were already the same at three months implies to me that they’re probably not going to change at any longer period. But still, we can’t know that for definite from this single study. And then They used untrained young males, which I’ve already talked about, and I’ve said that the growth might be greater than other people might see. So that, you know, it’s specific to this population group.

Okay and then finally within the study itself there’s a few comments around the practical applications of their study. So the first thing that they clarify, and I think this is really important, is they say that each participant did as few as two weekly sets. So remember the group that was in the one set group and they trained twice per week, well they did only two sets of pec deck exercises or pec fly exercises and they saw notable pectoralis major muscle growth in a 12 -week period. So anybody who’s not previously engaged in strength training can now engage in strength training and confidently know that even one set per exercise twice per week can start to show muscle size increases in a 12 -week period. And of course, there’s a plethora of research that shows exactly this, but we’re looking at this specific study, so it’s nice to know that. And they’ve said that that’s basically comparable to doing six weekly sets.

So you can imagine, it’s far more time efficient to do one set compared to three sets. And again, this is exactly what we do with the exercise coach, a single set, a science -based, you know, evidence -based approach to resistance training. And they also go on to say that increases in strength and pectoralis size can be achieved with a short training duration. So because the single set group only did one set of one exercise, they were training for less than five minutes in total time for that exercise session. So, you know, they’re effectively saying you can increase strength and muscle size in a matter of minutes. And that’s really important because many people perceive time and complexity to be barriers to engaging in resistance training.

Okay, so that’s kind of our research recap there. Any questions from any of that, Amy?

Wow.

No. So when you were first describing how the study was set up, you gave me the parameters of it, and it looked pretty good. And then what I appreciate is you described how it panned out and some of the results. And then you shared with us some of the limitations. But the conclusions being similar is that three sets of an exercise don’t necessarily lead to increased muscle size or more strength gain than one set. And so I think that’s a good point.

It supports what you shared in the previous episode about single set versus multiple set exercise. And the takeaway reminder to me is that strength changes everything. And what that means is that when you work out effectively and load your muscles properly, one set will and that short amount of time that it takes to do that one set can achieve the benefits that you’re looking for in so much less time, which is the whole idea behind this podcast and the whole idea behind how people can succeed with a shorter workout and that fits into their lifestyle. So I guess that’s what I take away from all of it. What are your takeaways or what are your insights?

Yeah, well this aligns. so closely with much of my own research from my own research publications. And then of course, it perfectly aligns with the evidence based approach that we take at the exercise coach of doing a single set per exercise to a high degree of effort and then moving on. And you know, they they sort of talk about the idea of doing one exercise taking only less than five minutes per session. But of course, at the exercise coach, you can get a full body workout in 20 minutes. One of the things that I think is really important within the study is they talk about supervision.

And I think we often look at resistance training studies and think, wow, these people got a lot stronger, or they got a lot more muscular, or they saw these great health benefits. I’m going to get the same if I go to the gym. But the reality is that supervised strength training is a lot more efficacious, is a lot more effective than unsupervised training. So many people listening to the podcast who aren’t clients of the exercise coach, they might go to a gym and they might well see strength or muscle size increases, but they would absolutely do better if they go to an exercise coach location and they get coached through a workout by a supervised coach. So I think that there’s a lot to take from the study, but I definitely think the supervision component is really important.

Right. And building upon what you just said, you know, picture the large gym scene. I mean, the statistics show 80 percent of people just do not. have the motivation or discipline or to self -guide a workout over a long period of time properly to get the results that they’re looking for. If that is you, then you’re actually in the minority of people who know what to do at the gym, go consistently enough, and build your progress all being self -motivated. That’s actually the

minority. That group of people is the minority. And so, no, most people will not do that. either with the consistency or the form or the knowledge or expertise that it takes to really to do that.

And that is the the key to success for most people is a coach, having somebody who will take the guesswork out for you and hold you accountable for that progress so that you don’t have to rely on your own motivation and knowledge. Right.

And so at the end of the day, that is what it’s all about.

And that is how people succeed.

Yeah. And I would even go one step further than that and say, even the people that think that they wouldn’t, you know, that they know enough and that they train regular and that, but they’re motivated and, and so forth, they would get more from a supervised workout. Um, you know, I’ve been engaged in strength training for probably the best part of 30 years of my life. And I, you know, I’ve done, you know, all the industry qualifications at one stage or another and coached, you know, multiple different people and worked as a trainer in multiple different environments. And yet I still know that if a coach comes and puts me through a workout, then my workout will be better than if I go and do it on my own. I know that that coach can improve my technique.

I know that that coach can enhance my effort. I know that that coach will improve my safety.

So we, you know, we’ve talked about, about supervision in previous podcasts, but I think that even people who believe that they understand all of those things would be surprised at the benefits they would get by, uh, by having a coach take them through a workout.

Totally.

Yep. Yeah. So if you’re listening to this today, just take away from this episode that you can achieve a fabulous. workout that will really truly deliver the results that you’re looking for in far less time if you do it with a coach. That’s my takeaway.

Thank you for breaking this down for us, Dr. Fisher.

I really appreciate it. it. I know our audience does love learning about research and having that evidence to fall back on that supports what they’re doing and what we’re doing. So thank you for doing that. And we will see you next week on the podcast. Until then, hope you remember strength changes everything.

Thanks for listening.

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