How hard you work in the gym will be a key determinant of the results you’ll see.
Once you’ve progressed past the novice stage just rocking up to the gym and completing a few bench presses and then a few dumbbell curls won’t cut it.
To see results you need to consistently hit the gym with a clear focused plan for every session. And, importantly, use progressive overload to ensure you are constantly upping your training intensity and pushing your body to continually adapt and grow.
But, on the intensity point, is training to failure necessary for muscle growth?
And, if so, should you train to failure on every set or just the last working set of a given exercise or at the end of a training cycle?
The TLDR answer is probably no, you don’t need to train to failure to see great results, particularly if your focus is hypertrophy.
But, as with many areas of fitness, there can be a more nuanced answer depending on your circumstances and goals.
And training to failure occasionally in a controlled manner may be beneficial for growth. And it can be an effective way of keeping yourself honest regarding the effort you are putting in.
Plus we have a word quota to fill. So read on for a more detailed answer and a look at what some of the research says and how it may impact your training.
What is training to failure?
Before we dive into the how, why and when it’s perhaps helpful to have a benchmark for what we mean by training to failure.
The various research on the matter generally uses one of 2 definitions.
Failure is defined as either the inability to move a specific load beyond a critical joint angle or as the incapacity to complete a repetition in a full range of motion due to fatigue.
Logically, gauging effort in the gym to provide a benchmark for improvement and progressive overload benefits from a consistent measure.
In our view, when working at your limit, it is easier to know if you’ve completed a full rep than it is to measure whether you exceeded a particular joint angle and/or point of motion.
We use a full range of motion for the vast majority, if not all, of our exercises, thus it seems sensible that any measure of failure should be based on the same benchmark.
There is a caveat, however.
Our definition of failure assumes good technique. We can all usually push out another rep with crappy form. So our definition is more correctly termed technical failure rather than absolute failure.
We will look at the research in more detail below. But when we discuss training to failure and/or measuring efforts on this blog (e.g. via reps in reserve), we will always measure failure as the inability to complete a full range of motion rep with good technique.
Why would I want to train to failure?
The theory goes that training to failure promotes greater activation of muscular motor units. The more motor units that can be recruited, the more muscle hypertrophy and strength gains.
However, despite logically making sense, there isn’t clear evidence that this is the case and therefore if there is any benefit to working to failure for either muscle growth or strength.
And while training to technical failure may create a greater training stimulus, it will also create a disproportionate amount of fatigue.
This in turn can negatively affect your workouts and recovery thus hamper your ability to hit the required training volume to see maximum results.
It’s well evidenced that training volume is a key determining factor for muscle growth.
But if training to failure prohibits you from accumulating sufficient volume, via excess fatigue, you may be leaving gains on the gym floor.
You simply can’t train to true technical failure for multiple working sets in a single session. If you think you can then you most likely aren’t working to failure.
This isn’t to say you shouldn’t work hard every set. You still need to work at a high intensity.
But for the vast majority of your training, you are best served to stop 1-3 reps short of failure to allow you to go again, both in session and from one session to the next, and reach sufficient volume to maximise your muscle hypertrophy.
That said, like knowing what working to true failure feels like, it will take time and experience to learn what 1-3 reps in reserves feel like.
As a novice trainee you will likely underestimate how hard you can work, via the ingrained human tendency for self-preservation, and leave more reps in the tank than planned.
This is where going to failure can help as it provides a means for keeping yourself honest and benchmarking your RIR (more on this below).
Plus it will show you what you can really do once you learn to smash through the mental blocks put in place by your ego.
What does the research say?
One of the more recent publications on the topic of resistance training to failure was this systematic review and meta-analysis by Grgic et al.
The authors looked at a range of studies that directly compared measures of strength and hypertrophy carried out to muscle failure versus not to failure and that shared similar control parameters. I.e. they only looked at human studies, studies over a set time frame, studies focused on resistance training only rather than those that also included cardio.
The upshot? 15 studies fit the bill and when viewing the pooled results the authors found no statistical difference between training to failure versus stopping short of failure for both strength and hypertrophy outcomes.
We can’t do justice to the full analysis in this summary and would urge you to take a look at the full report to get the full picture.
But the general conclusion is that training to failure isn’t necessary for maximising strength or hypertrophy.
That said the review authors note that the studies to date perhaps raise more questions than answers and thus it isn’t possible to draw definitive conclusions on the topic.
Also there generally isn’t a great amount of research into this topic and the simple variation in how one person reacts to training stimulus as opposed to another means that, again, it’s hard to draw strong conclusions.
As noted by the authors the research throws up some interesting observations and follow up questions.
The choice isn't every set to failure or no sets to failure
Many of the studies present a binary choice between working to failure and not failure.
In reality training is more nuanced than this and our intensity should change over time.
A sensible training problem will never see you training with the same intensity week to week. Rather, it has you increasing your workload over time.
You may spend the first 4-5 weeks of a 6-week plan gradually increasing intensity before going all out and working to failure in the final week.
You’d then follow this with a deload week before commencing a new cycle, hopefully at an increased workload (i.e. increased weight or sets).
If working to failure isn’t necessary, how close to failure should you train?
If we accept, as appears to be the case from the studies, that we don’t need to take working sets to failure, how hard should we work?
We know that muscles have to be sufficiently stressed to force adaptation so it feels right that working sets should be taken to near failure.
But how close is just right?
The fact is we just don’t know and have to go with what experience tells us and diligent performance tracking to keep abreast of any indicators that tell us we are working too hard, or perhaps not hard enough.
The general consensus is that 1-3 reps in reserve marks the sweet spot of sufficient stress while not being so overtaxing it limits your ability to complete workouts and reach sufficient volume/frequency targets.
But there isn’t currently any solid research that confirms this. Thus it is best to use it as a guide range and tailor your training according to your performance over time and any signs of overtraining or extreme fatigue.
Remember it will take time to learn how hard you can really push yourself in the gym.
And, especially as as a novice trainee, you are likely underestimating your abilities and recording a lower RIR than is really the case.
An RIR of 2 or 3 should still hurt and will take it out of you so you may want to test yourself every so often by actually working to failure so you learn what an RIR of zero and 1/2 feels like for various exercises.
Take a look at our longer read on reps in reserve for a deeper dive.
The exercise matters
The exercises you perform will also impact whether you should train to failure or not, and the overall impact and risks to your body of doing so.
Generally speaking, single-joint isolation moves (bicep curls, tricep rope extension, side lateral raises etc.) are not going to cause you too much systemic fatigue if they are taken to failure regularly. Indeed, why would you not push yourself as hard as you can?
On the flip side, taking deadlifts or squats to failure will, for most people, cause huge amounts of systemic fatigue. There is no argument that taking bicep curls to failure looks and feels very different to taking deadlifts to failure!
As a general rule working to failure is less of an issue for smaller muscles and isolation moves as you won’t cause excessive fatigue.
Indeed, don’t be scared to incorporate failure sets for these moves in your training plan. Either working to failure for the last set or building up to working to failure at the end of a specific training block/cycle.
You should avoid working to failure with the big compound moves (e.g. squats, deadlifts, bench press) too often, however. The amount of fatigue created and the injury risk is not worth the limited benefits (1RM strength PB chasing notwithstanding). Again, stick to 1-3 reps from failure to see the best results and maintain training longevity.
You be you
We try to stress on this blog that there are no absolutes when it comes to training.
Yes, there are key fundamentals you should try to live by regards training frequency, volume etc. But these concepts are always presented as a range.
Take training volume as a prime example.
Most research and training experience will suggest a range of around 10-20 working sets per muscle per week for optimal hypertrophic outcomes.
This is, however, a broad range and there is a big difference between 10 sets of chest exercise per week and 20.
In practice 2 different trainees may see very similar results despite training at opposite ends of the suggested range.
Conversely they may see very different results if training at the same volume.
Training intensity will follow a similar pattern with one trainee being able to recover from sessions taken to failure far quicker than another.
While we wouldn’t recommend taking multiple sets to failure regularly, you may find that you can do so with little ill effect.
To this end you will need to experiment and see what works best for you.
Make sure you track and review your performance and measure how an increase (or decrease) in intensity affects your recovery and gains.
Final thoughts
Current research seems to suggest that resistance training to muscular failure isn’t necessary to maximise increases in either muscle strength and/or hypertrophy.
While training to technical failure may create a greater training stimulus, it will also create a disproportionate amount of fatigue.
This in turn can negatively affect recovery, subsequent workouts and thus your ability to consistently hit the sufficient volume and intensity levels required to maximise muscle growth.
Our general view is that training to failure isn’t necessary or worth the injury risk. This seems especially clear if your focus is on training for hypertrophy.
In this case there seems to be a sweet spot of working 1-3 reps from failure to maximise growth and balance fatigue.
That said, it may be worth incorporating training to failure in your routine every so often, however, as both a means of benchmarking progress and keeping yourself honest regards your effort.
For example, working to failure on the last set of a specific exercise at the end of a training cycle/period wouldn’t be without merit, if done safely.
Also, as a general rule, working to failure is less of an issue for smaller muscles and isolation moves (e.g. bicep curls, calf raises, side delt raises) as you won’t cause too much fatigue.
You should avoid working to failure with the big compound moves (e.g. squats, deadlifts, bench press) too often, however. The amount of fatigue created and the injury risk is not worth the limited benefits (1RM strength PB chasing notwithstanding).
Finally a health warning – If you are training to failure please only do so with a competent spotter and/or safety bars in place.
