In this instructional video, Eric Roberts, a strength‑training coach with 12 years of personal lifting experience and over 20,000 coached clients, dismantles the common myth that low‑rep sets are only for strength and high‑rep sets only for hypertrophy. He explains that muscle growth is driven by mechanical tension and proximity to failure, not the rep range itself. Roberts outlines four actionable steps: (1) Recognize that any rep range can stimulate hypertrophy if sets are taken close to failure, emphasizing mechanical tension as the key stimulus; (2) Match rep ranges to exercise type—low reps (4‑8) for heavy compound lifts where load and form are critical, and moderate‑to‑high reps (10‑15) for isolation or accessory movements to enhance fatigue and mind‑muscle connection; (3) Apply the right intensity by ensuring the final 1‑3 reps of every set feel like a grind, using the “how many reps left until failure” self‑check to gauge effort; and (4) Prioritize progressive overload by tracking workouts, aiming to increase weight, reps, or quality each week, and sticking with the same exercises for 3‑6 weeks to allow measurable improvement. Throughout, Roberts offers practical cues, links to free workout programs, and a call‑to‑action for further coaching and nutrition guidance. By the end, viewers should understand that rep range is a tool, not a rule, and that effort and systematic progression are the true drivers of muscle growth.
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12 years ago, I thought low reps were for building strength and high reps were for building muscle. It turns out that was a myth that cost me years of progress. So in this video, I'm going to break down exactly what you need to know about high reps versus low reps, especially if your goal is to build muscle. I'll cover the top questions you probably have, like, does the rep range even matter? Which one builds more muscle and in what situation? Can you mix both, or should you pick one or the other? And is one better for beginner lifters versus advanced lifters? And after lifting for 12 years and coaching over 20,000 clients with their strength training, I'm going to give you the 4 biggest steps that I've learned will actually make a difference in your muscle building progress. And I promise, by the end of this video, you'll stop second-guessing your workouts And know exactly what you need to do to maximize your progress. So let's dive into the first step. Step 1, understand what actually drives muscle growth. One of the biggest mistakes I made early on, and what most people still do, is thinking that muscle growth is all about rep ranges. I would do 8 to 15 reps to build muscle and 3 to 6 reps to build strength. But here's the truth. You can build muscle with both if you do it the right way. The real mistake isn't what rep range you're doing, it's how you're training inside that rep range. For example, I used to only train in the 12 to 15 rep range to get the pump and feel the muscle burn, and because I thought that's what was going to build muscle. But my progress was stalling and my physique wasn't changing. Then I ran a program where I only did lower reps, which was in that 4 to 8 rep range. But because I was doing less reps, I was able to lift heavier weight and push myself harder. And within 4 weeks, I noticed a better pump in the gym, more muscle soreness, and most importantly, more muscle growth. This is when I realized it wasn't the rep range that I was doing that was holding me back. It was the lack of intensity in my workouts. And by the way, if you want a free workout program with lower rep ranges in it, there'll be a link in the description of this video below. So here's what actually causes your muscles to grow: something called mechanical tension. And this is just a fancy word for the stress that you place on your muscles when you're training. And guess what? You can create that tension in any rep range if— and this is the key— you take that set close to failure. This is what makes your body say, we need to adapt to this stress and we need to grow bigger, stronger muscles. So whether you're doing 5 reps or 15 reps, the question isn't how many reps. The question is, did that set actually challenge me? And how do you know if a set is actually challenging enough for you to cause muscle growth? Well, don't worry, we're actually going to cover that in step 3 of the video. But first, now that we know technically any rep range can build muscle, that doesn't mean there aren't better rep ranges than others for muscle growth. Step 2, know the strengths and weaknesses of high reps versus low reps. Once I realized high and low reps could both build muscle, I made another mistake. I've made plenty of mistakes in my life. I tried to use the same rep range for every single exercise that I did in my workouts. If I was doing 15 reps, I would do 15 reps on squats and bicep curls. Or if I was doing 5 reps on deadlift, I was doing 5 reps on a shoulder raise. That's like trying to use a hammer for every job in your house. Sometimes you need a screwdriver. Sometimes You need a drill. And sometimes you just need to hire somebody and call them to take care of it for you. That's what I do. I remember switching my Romanian deadlifts from 10 to 15 reps down to 6 to 8 reps, and instantly I felt stronger and safer since I could lift heavier weight and didn't fatigue myself. But then I tried doing 6 reps on a side lateral raise, and it was a disaster. My joints hurt, my form broke, down, I was using way too much momentum. So then I bumped the rep range up to 10 to 15 reps, used a bit lighter weight but still pushed myself, and instantly my joints felt better. I didn't have to use as much momentum, which meant I then felt and worked my shoulder muscles more. And that's when it clicked— different rep ranges work better for different exercises. Here's how I think about it now. I use lower reps, usually 4 to 8 reps, for big compound lifts where form and the weight that you lift matter the most. And these are things like squats, bench press, deadlifts, Romanian deadlifts, hip thrust. And then I use more moderate to high reps for more isolation and accessory movements where you're isolating one specific muscle and maybe you're not trying to lift as heavy of weight as you would on a deadlift. These are things like bicep curls, shoulder raises, tricep extensions, even things like lat pulldowns or rear delt flies. Lower reps equals more load and more strength, and higher reps equals a bit more fatigue and a bit more mind-muscle connection. Both build muscle if used in the right context. And switching rep ranges for certain exercises doesn't mean you're doing something wrong. It means you're finally doing it Smart. And again, by the way, if you want a free workout program with both low and high reps, click the link in the description of this video. But rep ranges are really just the start. What really matters is how hard you're pushing yourself in the rep ranges and if you're actually challenging yourself enough to grow muscle. So next, I'll show you exactly how to train no matter what rep range you're using so you actually see progress week over week. Step 3, apply the right intensity to your workouts. This step is where most people fall short. They think they're training really hard, but the truth is you're probably not lifting heavy enough and you're stopping your set way too early. You finish a set and think, that felt pretty good. But if you ask yourself how many reps did I really have left in the tank until I went to complete failure? And if the answer is 5 or more, you're not even close to sending the signal to your body that is needed to build muscle. When I first started tracking my effort in my workouts, I realized something pretty quickly. Most of my sets, especially with higher reps, I was stopping the set too soon. I wasn't struggling. The last The last few reps didn't really feel any different than the first few reps, other than, yeah, my muscles were burning a bit. So I made one rule for myself: the last 1 to 3 reps of any set that I do, no matter what the rep range is, those last 1 to 3 reps should feel like a grind. Not sloppy, but tough and challenging, like I might not get the next rep. And you know what? My physique changed faster in 3 months than it had the previous year because I finally stopped going through the motions and I finally started lifting heavy enough and pushing myself hard enough to build muscle. So here's how you know if your sets are actually challenging you enough to build muscle. After a set, ask yourself, how many more reps could I have done until complete failure? If the answer is more than 3, you didn't push yourself hard enough and you need to get heavier weight next time to make it hard enough. And number 2, the last 1 to 3 reps of your set. And yes, this is every set that your workout calls for, not just the last one, should be difficult and challenging. You're breathing heavier. You're not sure if you're going to get those last couple of reps. And most importantly, the speed of the reps starts Slowing down on the way up. That's called proximity to failure, and it's one of the biggest predictors of if you're going to build muscle or not. Not the reps you did, but how close you got to your limit for that rep range. So now that you know how hard you really need to push, even if you're training hard enough and you're not doing the thing in our next step, then you're leaving results on the table. So let's talk about what progress actually looks like and how to make sure you're moving forward every time you work out. Step number 4, focus on progression. Even if you're pushing yourself and training hard, here's where people lose momentum and progress. They do the same weights for the same reps week after week after week. They feel like they're training intensely, but the results stop coming. Why? Because effort is step one, but progress is what really drives change. If your logbook of your workouts looks the exact same week over week, that's probably why your physique does as well. Or you might not even be tracking your workouts. You might just be training till exhaustion or going until it feels hard. I know we said you need to train close to failure, but that feeling isn't enough to make progress. You need to have numbers to prove so. When I first got serious about tracking my lifts, I was shocked at how inconsistent I actually was. I'd go hard, but it wasn't intentional. One week I would do 10 reps. The next week I would do 8 reps. The next week I would go back to 10 reps. In one week I lifted 5 pounds more, but the next week I lifted 10 pounds less. There was no structure. There was no progression. Week to week, once I locked in and said each week my goal is to beat what I did last week, even by just a little, that's when I saw my body start to change. And progress doesn't mean you're doubling your weight every workout; it means one more rep than last week, or two and a half more pounds than last week. It might mean a little bit better form and range of motion, or a better control. Over the weight than what you had last week. If you stack that over time, the results are going to speak for themselves. This is what we call progressive overload, and it's a fancy term, but it's very simple. Here's how to know if you're having progressive overload. Week over week, month over month, you need to be increasing the reps that you are doing, or you need to be increasing the weight that you are lifting. And you need to track your lifts, not just mentally, but in a logbook or in an app. For example, I have my own fitness app that I built for our clients, and inside of it you can see we track our workouts. It shows you what did you do last week compared to this week, and it allows you to beat that week over week. And with this, you should be sticking with the same exercises for 3 to 6 weeks. So it's long enough for you to actually get better at them week over week. Do not just chase random workouts or don't just chase the feeling of working out hard. Chase measurable progress and improvement. That's how you'll build muscle that actually lasts. Now that you've got the full picture, reps don't really matter without effort. Effort means you're pushing close to failure. Progress means getting better week over week. And you can do any rep range to build muscle. And if you want a simple workout program that you can follow, click the link in the description of this video. Or if you're interested in getting coached by myself and our team and letting us take care of all of your workouts and all of your nutrition, there'll be a link in the description of this video as well. And speaking of nutrition, if you're like, okay, I learned this about workouts, but my nutrition sucks, Watch this video here to have me break down nutrition in a no BS simple way.
