Should we lift to failure when trying to gain muscle size? That’s a tricky question, and the answer depends on the situation. For example, experienced lifters are able to lift to failure more safely, but they stimulate more muscle growth by stopping just shy of failure, at least on compound lifts. Beginners, on the other hand, can build muscle faster by lifting to failure, but since they don’t have the skill to take compound lifts to failure safely, training to failure is best reserved for isolation lifts.
The situation grows murkier when we consider that it’s often better to leave reps in reserve when lifting in lower rep ranges, whereas lifting in higher rep ranges often demands that we push closer to failure.
Perhaps most importantly of all, it’s often hard to estimate exactly how many reps we’re leaving in reserve, and if we misjudge our efforts and fail to push ourselves hard enough, we may wind up failing to stimulate any muscle growth whatsoever.
In this article, we’ll cover the research looking into training to failure as it relates to gaining muscle size, discussing the nuances of when you should and shouldn’t leave reps in reserve.
- What is Training to Failure?
- Does Training to Failure Stimulate More Muscle Growth?
- When Should You Train to Failure?
- Always Outlifting Yourself
What is Training to Failure?
The first thing we need to do is define failure. To some people, failure is when your training partner can no longer curl the weight you’re trying to bench press. To others, failure is when the set starts to feel too uncomfortable. Neither of those situations is failure.
There are a few good definitions of failure that you’ll commonly see, each with their own nuances to them:
- Total failure: you cannot move the weight anymore, even with deviations in technique. The powerlifter who fails his deadlift with the bar a few inches off the floor—that’s total failure. This isn’t usually advisable during regular training sessions.
- Technical failure: you cannot move the weight anymore with proper technique. The bodybuilder who stops his set of deadlifts when he feels his lower back start to round is stopping at technical failure. This is how most people train to failure when trying to gain muscle size.
- 0 Reps in Reserve (0 RIR): you haven’t actually failed yet, but you know that you wouldn’t be able to do another complete repetition—you have no reps left in reserve, no reps in the tank. This is often better than technical failure for stimulating muscle growth, but it’s also more subjective—you have to guess how close to failure you are.
- 10 RPE: you haven’t necessarily failed, but your rating of perceived exertion (RPE) is at “max.” A 10 RPE usually corresponds with 0 reps in reserve, and so RPE and RIR are often (but not always) used interchangeably. We generally prefer using the reps in reserve system, since it’s a little easier to understand.
The distinctions here are small, but they can be meaningful. Someone stopping at technical failure might stop their set of deadlifts right before their lower back rounds, even if they could have done another couple of reps with a rounded back. This means less shear stress on the spine, a lower risk of injury, and they’ll feel less fatigued afterwards. But have they really gone to failure? Maybe not. It depends on how you define failure.
The next distinction happens when comparing 0 RIR with training to technical failure. Lifting to technical failure means grinding out as many reps as you possibly can, only stopping when you fail to complete a rep. The final rep, then, will have you actually failing at the sticking point. It’s objective: you lift until you fail, and so you learn exactly what you’re capable of.
If you were lifting to 0 RIR, though, you’d be stopping when you don’t think you can get another rep. There’s some guesswork involved. It’s subjective. In order to find out for sure how many reps you have left in the tank, you’d have to take the set all the way to technical failure. This makes it somewhat of a more advanced method. You already need a good understanding of what you’re capable of.
With bodybuilding and hypertrophy training, it’s usually recommended to stop at or before technical failure to reduce the risk of injury. For instance, it’s oft wise to avoid deadlifting with an excessively rounded lower back. On the other hand, with safer lifts, such as chin-ups and barbell curls, you’ll often see bodybuilders taking their lifts all the way to total failure, sometimes even cheating or swinging a little bit.
The next question is whether we should train all the way to technical failure or intentionally stop short. Both can be done safely, so now we’re considering how much muscle growth is stimulated, as well as how much muscle damage and fatigue it generates. There are a few popular approaches that you’ll find in bodybuilding and hypertrophy programs:
- No, we shouldn’t train to failure. That way we stimulate a comparable amount of muscle growth but with a lower risk of injury, burden ourselves with less fatigue, and recover faster.
- Yes, we should train to failure, but only on the final set of each exercise. That way we ration our energy from set to set, potentially allowing us to get more total reps—a higher training volume—but we still get any potential benefits of training to failure on the final set.
- Yes, we should train to failure, but only on our isolation lifts. That way we aren’t accruing fatigue or risking injury on the bigger compound lifts, but we still get to bring our muscles close to failure on our isolation lifts, which are often safer and easier to recover from.
- Yes, we should train to failure. That way we’re always training hard, always know exactly how strong we are, and are always pushing our muscles outside of their comfort zones. It makes our progress easier to measure, and there’s less risk of running into muscle growth plateaus due to lack of sufficient effort. With that said, it doesn’t necessarily stimulate more muscle growth, and it’s quite a bit more fatiguing.
All four of these approaches can make sense, depending on your goals and what kind of training you’re doing. The two approaches in the middle might sound like they make the most sense, giving us the best of both worlds, but they both assume that training to failure stimulates more muscle growth than stopping just shy of failure. After all, if there’s no extra growth stimulus from going all the way to failure, why would we ever do it at all?
Do we stimulate extra muscle growth by lifting all the way to failure?
Does Training to Failure Stimulate More Muscle Growth?
34% More Growth from Stopping Shy of Failure?
In a recent study by Santanielo et al, the researchers had the participants do one-legged leg presses and knee extensions. With one leg, they stopped just shy of failure, and with the other leg, they went all the way to muscular failure. This is about as perfect as a study could get, given that we’re comparing the muscle growth between limbs on the same person.
On the legs that lifted all the way to muscle failure, they saw a 13.5% increase in muscle size, whereas on the legs that stopped just shy of failure, they saw an 18.1% increase in muscle size. That means that by stopping their sets just shy of failure, they were able to increase their muscle growth by around 34%.
What makes this study even more interesting is that when training to failure, people were able to get an average of 12 reps per set, whereas when stopping just shy of failure, they were able to get 11 reps per set, meaning that even though the failure legs had a higher training volume—they did more total reps—they saw less growth than the non-failure legs. The other thing to note is that, at least on average, the participants were able to accurately stop their sets a single rep shy of failure. (I suspect it helped that they were taking one leg to failure. They got to feel exactly what failure felt like with that muscle group and with that rep range, allowing them to stop just shy on their other leg.)
So what we’re seeing here is that stopping shy of failure seems to increase muscle growth, even though it reduces total training volume. The catch being, of course, that just a single rep is left in the tank, which can take quite a bit of practice to master.
A Quick Review of All Failure Research
Now, this is just one study. At the time of writing, there are fourteen relevant studies. Some show more muscle growth from pushing harder and going closer to failure (Goto, Martorelli, Karsten, Tareda), others show a benefit to stopping just shy of failure (Santanielo, Carroll, Lacerda, Pareja-Blanco 2, Pareja-Blanco 3), and yet others show mixed results or no significant differences in muscle growth (Helms, Sampson, Pareja-Blanco 1, Nóbrega, Lasevicius). So, overall, it looks a bit foggy, right? Not quite. If we gaze a little deeper, a clearer picture emerges from the mist.
Greg Nuckols, MA, noticed that when untrained lifters were doing lighter isolation lifts, they stimulated more muscle growth by lifting closer to failure. When he crunched all of the numbers, the effect size wound up being quite large, too, with around 56% more muscle growth from taking those isolation lifts to failure.
With intermediate and advanced lifters, though, the findings were almost the exact opposite. When seasoned lifters were doing heavy compound lifts, they built more muscle when they stopped shy of failure. Here the effect size was smaller, but there was around 25% more muscle growth from stopping sets shy of failure.
So what we’re seeing is that although there are situations where lifting to failure helps, there are also situations where it doesn’t. Here’s a rough breakdown of when it can be helpful to train to failure:
- Beginners: new lifters stimulate more muscle growth by lifting to failure.
- Seasoned lifters: intermediate and advanced lifters stimulate more muscle growth by stopping just shy of failure.
- Compound lifts: when doing the bigger compound lifts, we stimulate more muscle growth by stopping just shy of failure. So for squats, deadlifts, barbell rows, and bench presses, there’s less need to go all the way to failure.
- Isolation lifts: when doing smaller isolation lifts, we often stimulate more muscle growth by taking our sets closer to failure.
- Heavier rep ranges: when lifting in heavier rep ranges, we stimulate more muscle growth by stopping shy of failure. So for sets of 1–7 reps, it can help to leave reps in the tank.
- Lighter rep ranges: it seems that as our rep ranges get higher, we stimulate more muscle growth by lifting all the way to failure. So for sets of 15–30, it helps to push harder.
Let’s dig a little deeper into these variables.
When Should You Train to Failure?
Should Beginners Lift to Failure?
Yes, beginners should practice lifting to failure, but mainly with their isolation lifts. It seems that beginners lack the coordination or experience needed to stimulate a maximal amount of muscle growth if they stop their sets shy of failure. As covered above, the best summary of the data comes from Greg Nuckols, as seen in his article about effective reps, where he concluded that new lifters build muscle faster by taking their sets all the way to failure. Now, that might sound like he’s recommend that beginners go to failure, but that’s not quite the case. There are other factors to consider, too, such as ingraining good lifting technique and avoiding injury.
I asked Greg what his advice for beginners was, and he responded with:
For training new lifters, I personally like to keep them far from failure on compound lifts, with the goal of teaching good technique, but also choosing single-joint exercises that will let them go to failure safely, getting them a bit of a pump.Greg Nuckols, Stronger by Science
So if you’re a new lifter, it’s probably wise to stop your compound lifts before our technique starts to break down, which likely means stopping a couple of reps shy of failure. Then, as your technique gets better, and you’re able to push harder without your form breaking down, you can push your compound lifts a bit closer to failure. By that point, of course, you’ll likely be experienced enough that you won’t need to go all the way to failure, though, at least not on the majority of your sets.
With isolation lifts, though, it’s the opposite. These are your opportunity to truly challenge your target muscles. If you want bigger arms, take your sets of biceps curls, triceps extensions, lateral raises, and so on all way to failure, that way you ensure that you’re stimulating maximal muscle growth. The same is true with every muscle group. If you’re eager to grow your legs, do some leg extensions and hamstring curls to failure. Then, as you get better at pushing yourself, becoming more of an intermediate lifter, you can ease back on training to failure, stopping just shy of failure on most sets, and perhaps saving failure for just the final set of each isolation exercise.
Should Experienced Lifters Train to Failure?
No, intermediate and advanced lifters shouldn’t lift to failure, or at least not by default. If we look at the research, intermediate and advanced lifters seem to benefit from stopping their sets just shy of failure, leaving 0–3 reps in reserve. By leaving reps in the tank, not only do their workouts become safer, they also become easier to do, easier to recover from, and they stimulate more muscle growth.
That’s not a hard and fast rule, though, just a loose rule of thumb. There’s nothing wrong with taking your final sets to failure, with pushing harder on your isolation lifts, or with taking sets to failure when lifting in higher rep ranges. In fact, lifting closer to failure in those circumstances may even stimulate more muscle growth.
So, for instance, best to stop your 6-rep set of squats shy of failure. But when doing a 15-rep set of lateral raises, you may stimulate more muscle growth by going all the way to failure.
The Problem of Estimating Reps in Reserve
One of the big disadvantages of stopping sets before reaching muscle failure is that most people underestimate how many reps they’re leaving in reserve. For instance, in this study, when asked to choose a weight they thought they could complete 10 repetitions with, most of the participants were able to get 15 reps before hitting muscular failure. That’s not enough to stimulate a maximal amount of muscle growth.
For another example, in this study, when asked how many reps they were leaving in reserve, most of the participants were off by at least a couple of reps. Again, this can create the problem of people not pushing themselves hard enough to stimulate much muscle growth.
On the other hand, when people lift all the way to failure, no, it might not be perfectly ideal, but at least it’s guaranteed to stimulate muscle growth. Yes, you might stimulate something like 20% more growth if you stopped exactly one rep shy of failure, but that’s not always easy to do. So by training to failure, at least you’re guaranteed to stimulate some growth.
Now, this doesn’t mean that people need to always take their sets to failure in order to guarantee muscle growth, it just means that we should sometimes take our sets to failure so that we’re constantly testing our estimations and improving our ability to gauge how hard we’re pushing ourselves.
Should You Take Compound Lifts to Failure?
This is a hard question to answer. Everyone is a bit different, and each lift has its own nuances to it. For example, depending on what your weakest link is, taking a low-bar barbell back squat to failure can be quite rough. If your lower back collapses under the weight and you wind up pinned under the bar, having to lower it awkwardly down to the safety pins, that can be hard on your spine, and something that you want to avoid doing every single set or every single workout. On the other hand, if your quads gas out long before your back does, and you’re able to lower it down to the pins while still maintaining a neutral spine, well, that’s entirely different—it’s much safer.
Different lifts have different dynamics, too. If we look at something like a front squat, where any deviation in spinal position causes us to dump the bar forward, we see that it’s a lift that can’t really be cheated. The racked position we hold the bar in is also a safety feature, designed to make it easy to dump the bar in an emergency. If we can’t lower the bar safely to the pins, we can just push the bar off our shoulders and step back. In fact, if you’re using bumper players, you don’t even need to lift with safety pins. It’s a squat variation that makes it safer to push ourselves harder.
Another example of a lift that’s well-suited to being pushed harder is the chin-up. If you can’t bring your chin to the bar, you lower yourself back down, curse a few times, and that’s that. There’s no real harm in taking the set all the way to failure. Plus, since the sticking point is when our muscles are in a contracted position, we aren’t even causing all that much muscle damage by taking our sets to failure (as opposed to something like a bench press, where we fail our sets with our muscles at longer muscle lengths). More on that here.
Now compare that chin-up example against the bent-over barbell row, where we’re more likely to fail in our spinal erectors. Is that dangerous? Not necessarily, especially if you’re strong at your deadlifts. You might be rowing with 225 pounds, deadlifting with 415 pounds. The load is so much lighter that there’s little risk in it injury your back. But the fatigue the lift can generate is tremendous. If your lower back is giving out at the end of every set, you’re going to generate a ton of fatigue in your spinal erectors, which can make it harder to push yourself with your deadlifts, squats, and overhead presses. If you want to take your rows all the way to failure, then, you might want to choose a chest-supported row variation.
Finally, and perhaps most importantly, if your technique on the compound lifts isn’t rock solid, then it’s probably not the best time to be taking those sets to failure. When a newer lifter takes their final sets to failure, technique breakdown can be severe, and that may (debatably) wind up ingraining poor form. It can also increase the risk of injury. Better to master the lift and then push yourself closer to failure.
Should You Take Isolation Lifts to Failure?
With compound lifts, we have a number of safety and technique factors to consider. With isolation lifts, though, they’re often lighter, safer, and simpler, allowing us to push closer to failure with less risk of injury. Plus, since we’re less likely to fail with our spinal erectors, the fatigue that isolation lifts cause tends to be easier to manage as well.
For example, let’s say that you do a few sets of the bench press, never quite reaching failure, and likely not bringing your triceps anywhere close to failure. That can be a good time to toss in some skullcrushers, and there’s little reason to avoid failure when doing them, especially on your final sets. The same is true with following up chin-ups with biceps curls, or overhead presses with lateral raises. Assuming these lifts aren’t hurting your joints, there’s little harm in pushing harder, and even if you take them to failure, they won’t generate all that much overall fatigue.
Finally, and perhaps most importantly, if you’re a newer lifter and you aren’t taking your compound lifts to failure, then there’s a real risk that you aren’t challenging your muscles enough to provoke muscle growth. That’s where taking isolation lifts closer to failure becomes all the more crucial, since they give us an opportunity to truly push ourselves.
The Minimalist Approach
One of the main advantages of stopping our sets shy of failure is that it allows us to recover better. We preserve more strength from set to set, we preserve more energy as we move deeper into our workouts, and we inflict less muscle, allowing us to train our muscles more often. but many of these advantages disappear if we’re only doing a couple of sets per exercise, a couple of exercises per workout, and a couple of workouts per week. If we don’t need those recovery advantages, there’s more of an argument for pushing ourselves harder each set.
That’s why some minimalist approaches to training, such as Reverse Pyramid Training, can work well when taking our sets closer to failure. Perhaps not failing our reps, but at least lifting until we don’t have any reps in reserve, stopping just, just shy of failure. Is that the very best way to build muscle? No. But it’s highly efficient.
Plus, when doing minimalist programs, it’s more important than ever to make sure that you’re challenging yourself enough to stimulate growth. When you’re taking all of your sets to the brink of failure, you can get a very clear idea of whether you’re actually getting stronger from workout to workout. If you aren’t, you might need to start doing more sets per exercise. That’s crucial feedback that can be hidden by always staying further from failure.
Always Outlifting Yourself
The main disadvantage of stopping shy of failure is that it can often get in the way of progressive overload. If you’re following a good program, writing down how much weight you’re lifting, and showing up every working fighting to lift more weight or eke out more reps, then it’s not an issue—it’s perfectly fine to stop shy of failure.
The problem is when people get in the habit of stopping their sets when they get painful or hard. In order to keep stimulating muscle growth, we need to continue challenging ourselves, and that will often mean that our workouts go through periods of getting harder. This is where the lifters who train to failure often win out, since they always exert themselves fully, and so any improvement in size or strength is immediately visible in the extra reps or extra weight that they can lift. Any lack of progress is also visible. If you’ve failed halfway through your seventh rep for five weeks in a row, you know that you’ve hit a plateau.
Because training to failure takes the subjectivity and guesswork out of our progress, it’s often a more idiot-proof way of training. Not that it’s better, just that it’s simpler. If that’s something you think you might benefit from, and especially if you’ve hit a plateau, you might want to start taking the final set of each lift to failure. If you aren’t improving from workout to workout, or at least from month to month, then you need to adjust your workout program or your diet (as eating enough protein and calories is another crucial part of building muscle).
Overall, what we see is that for intermediate lifters, it’s usually best to stop just shy of failure, leaving somewhere between 0–3 reps in reserve. Maybe on heavier compound lifts that means leaving 3 reps in reserve on the first set, 1 rep in reserve on the final set. Then, with isolation lifts, maybe that means leaving 1–2 reps in reserve on earlier sets, 0 reps in reserve on the final set.
However, there are a few situations where lifters benefit from pushing even harder and lifting to failure:
- Beginners aren’t great at contracting their muscles yet, and so they can benefit from doing simple isolation lifts and taking them all the way to technical failure.
- When training with lighter loads, it’s often better to lift to failure. This can be especially important when doing bodyweight hypertrophy workouts, such as when doing high-rep sets of push-ups.
- When doing minimalist workout programs with just a couple of sets per exercise, just a couple of exercises per workout, and just a couple of workouts per week, it can help to push harder, taking our sets right to the brink of failure.
- It can often be helpful to take at least some sets to failure some of the time. Not because it stimulates more muscle growth, but because it helps us learn how many reps we’re actually leaving in reserve when we stop shy of failure.
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