The subject of training to failure is by no means new. However, there’s been a recent surge of interest, which has sparked discussions on podcasts, social media posts, etc. Often, these conversations are discussed in a should you or shouldn’t you format. In my opinion, this method of comparison is inappropriate since both approaches have produced a long list of elite-level physiques.
Therefore, the purpose of this article is not to make a black-or-white comparison but to evaluate the relevant evidence (both research and anecdote) in an attempt to highlight the strengths and weaknesses of each approach.
From there, we can go beyond theoretical constructs and shift to effective applications for hypertrophy.
What The Research Says About Training To Failure
A 2016 systematic review and meta-analysis by Schoenfeld et al. compared the effects of various training volumes on markers of muscle growth (1). Unsurprisingly, the data found a dose-response relationship whereby higher training volumes resulted in greater muscle hypertrophy.
If you follow the evidence-based fitness community, you may have even heard people discussing a recent paper titled “Effects of Different Weekly Set Progressions on Muscular Adaptations in Trained Males: Is there a Dose-Response Effect?” which sparked some controversy on social media (2). The pushback was in response to the researchers' prescription of volume. One group eventually reached 52 sets of legs per week, which resulted in the greatest hypertrophy across groups. Ironically, this study didn’t really add anything new to the literature and primarily just reaffirmed what we already knew. Which is essentially that for a certain period, and so long as you can recover, more volume generally equates to more muscle growth.
A 2021 paper by Dos Santos et al. found, “Compared with NF [non-failure], MF [momentary muscular failure] resulted in a higher number of repetitions in the first set (11.58 ± 1.83 vs. 7.58 ± 1.72, p < 0.05), but a lower in the last set (3.58 ± 1.08 vs. 5.41 ± 1.08, p < 0.05). Total number of repetitions was similar between the protocols (MF 26.25 ± 3.47 vs. NF 24.5 ± 3.65, p > 0.05). In both protocols, there were significant decreases in maximum and mean movement velocity loss and power output loss, but higher decreases were observed in MF than NF (p < 0.05).” (3). These findings are in line with the broader literature, which suggests that the additional fatigue cost of training to failure can temporarily impair performance.
A 2020 paper published in the Journal of Strength and Conditioning Research found that closer proximity to failure resulted in greater fatigue accumulation, which slowed the rate of recovery. Hormonal responses were also impaired, and greater muscle damage was found as well (4). One study titled Strength Training with Repetitions to Failure Does Not Provide Additional Strength and Muscle Hypertrophy Gains in Young Women by Martorelli et al. found that when volume is equated, training to failure is not necessary to see marked improvements in hypertrophy and strength.
Ultimately, the aggregated data suggests that training to failure or just shy of failure seems to produce similar hypertrophy. We can quantify this as 3 RIR (repetitions in reserve) or less. But, as I mentioned in the beginning, what’s often lacking in these findings is context.
Practical Elements Of Failure vs Non-Failure Training
This is where things become a bit more interesting. A 2017 paper by Helms et al. assessed male and female powerlifters' ability to select appropriate loads to match the prescribed rep and RPE targets. Researchers found that “powerlifters can accurately select loads to reach a prescribed RPE. However, accuracy for 8-repetition sets at 8 RPE may be better for bench press compared with squat. Rating squat power-type training may take 3 weeks to reach peak accuracy” (5). In short, powerlifters are pretty good at rating RPE accurately. This paper is often used to support non-failure training. However, in real-world scenarios, we run into a few practical issues with this model.
If you never train to failure, how can you possibly assess how close you are to failure? Additionally, as you become more advanced, you’ll need to recalibrate your RPE. The only way to accurately do this is to train to failure.
Even the most disciplined lifters see a reduction in effort over time. Training to failure is sometimes necessary to ensure training effort is sustained.
Additionally, when comparing the efficacy of failure to non-failure training, we often rank the “winner” based on the best stimulus to fatigue profile. Although this makes a lot of sense in some instances, it’s lacking in nuance. For instance, the fatigue cost of training low bar squat to failure is radically different than training biceps or lats to failure. Thus, there are likely instances where the additional fatigue is irrelevant because the time course for recovery still permits training volumes and frequency that fall within an optimal zone for hypertrophy, so to speak. There’s also a big difference between taking every set to failure and just one set to failure.
A 2017 paper by Moran-Navarro et al. found similar results when assessing the time course for recovery among their subjects (6). I should clarify the paper was not specifically comparing all sets to failure vs one set to failure. However, the study design and findings allow us to extrapolate this from the data into an applied setting. There’s also significant inter-individual variability in response to volume and intensity. Any experienced coach can testify that some individuals can only tolerate a small amount of volume and get incredible results. Others require absurd volumes and intensity to see similar adaptations. And the one thing I want to stress here is at the end of the day, your results and/or your clients' results are the primary determinant of what’s effective.
When looking at the practices of elite bodybuilders, many (maybe even most) of them utilize failure training in their approach. Some people will brush this off since it’s not peer-reviewed literature. But I should remind you that these are the individuals who have the most muscle and simultaneously produce the best bodybuilders. So, although you can point to instances of bodybuilders being incorrect in the past, keep in mind that researchers have been wrong on at least as many things, if not more. Therefore, it’s wise to be open to learning from the people who have accomplished the most in this respect. Keep in mind that if we extend the timeline out, most lifters will cycle through higher and lower volumes, as well as higher and lower intensities. This is part of the process of periodization and discovering what works most effectively for you at a given point in your lifting career. By extension, if you never train to failure, or you never train shy of failure at higher volumes, you’re likely missing out on progress.
When we get deep into the individualization realm, we also have to take temperamental differences into account. Some individuals just like to train hard. Prescribe them 5x8 @ RPE 8, and you know they’re taking every one of those sets to failure. Conversely, not all clients will push themselves to the appropriate RPE target. Therefore, prescribing multiple sets to failure may be required just to get them to reach an RPE 8. Since adherence to a program is heavily influenced by the athlete's level of enjoyment and buy-in, it’s often in the coach's best interest to take personal preferences into consideration.
Earlier this year, I was on the Table Talk podcast, and Dave asked me about one of the things I’ve changed my mind on over the years. One of the points was training to failure. Previously I had never tried it, but I understood the conceptual argument, which led me to not see a clear benefit to it over training just shy of failure. However, after going through several blocks utilizing this approach in various parts of my program, I gained new insight into its potential benefits. For instance, if you train to failure there are potential orthopedic benefits since the total volume will necessarily be reduced. Some people might argue that any potential benefit might be outweighed by the additional stress of taking sets to failure. This is a reasonable conceptual argument, but it doesn’t always pan out like that. Especially when you factor in individual variability.
Additionally, people often neglect the SAID principle (Specific Adaptations To Imposed Demands), which suggests that people have the capacity to adapt to this style of training. No one disputes this when discussing other approaches, but for some reason, it’s seldom mentioned (if mentioned at all) when debating the pros and cons of training to failure. Coaches will utilize volume landmarks to prescribe appropriate doses during various periods of development.
But regardless of the volume prescribed, the one metric that needs to remain high is intensity of effort. Intensity of effort is different than simply intensity, which refers to your maximum capacity at a given task (i.e., sprinting, 1RM squat, etc.) Intensity of effort can be scaled to various volumes and activities, but it still needs to remain above a certain adaptive threshold. As volume and intensity undulate, it may be beneficial to utilize failure training periodically to drive adaptations.
To Summarize The Main Points Of This Article
- Most elite-level bodybuilders utilize training to failure. These are the most muscular athletes on the planet, and they have also produced the highest number of muscular athletes, which means their approach has been validated.
- The effects of training to failure are contextual. A barbell squat is not the same as a pec dec in the subsequent fatigue that can be generated. Additionally, the time course for recovery might make slightly longer recovery times less relevant, such as when training your biceps. Even if you take those exercises to failure, you can still likely train them three times per week without seeing a reduction in performance.
- There is significant interindividual variability regarding tolerance to intensity and volume. Some people can just handle higher intensity better; others can handle higher volumes. It’s important to test these variables and implement what actually works for a lifter over what should theoretically be best.
- If you’re constrained by time, pushing to failure on certain exercises can be an effective way to still generate a robust stimulus within a short period of time due to the decrease in total volume. This point wasn’t discussed previously, but it does warrant mentioning.
- At some point, you will likely train to failure, just shy of failure, and everything in between. This is the real crux of the position this article is taking. If you train long enough, you will most likely utilize the entire spectrum of effective approaches.