Training to failure is one of the most controversial training methods: some say that it enhances your results, idiot-proofs your training, and ensures serious results, while others say that it’s pointless and likely to cause injury.
The truth is somewhere in the middle - you can get serious results via training to complete failure, but it doesn’t seem to be necessary in most cases. In many cases, training to near failure is more than sufficient, and entails fewer risks.
Recent research is beginning to show that while training to failure doesn’t seem likely to cause injury, it does increase recovery time without meaningfully increasing your results, meaning it should be used sparingly and strategically.
Some of the problems of training to failure are amplified at extreme intensities, so it seems unlikely to be a good idea to use training to failure very frequently when training for strength or endurance. Instead, it seems to be a better fit when training for size.
Author’s Note: A lot of the research for this post was drawn from the MASS Research Review. I always recommend checking it out if you’re interested in getting all the latest research summarized in an easily readable format.
Training to failure is training to the point at which you can no longer perform any additional reps - whether that means actually failing a rep midway, or quitting between reps because your last one was a real grinder and you know that if you had to do one more, it wouldn’t work out.
“You’ve got to train to failure, or it doesn’t count.”
Perspectives like this are pretty common in the broscience community, where training to failure has sometimes taken on an almost mystical quality. The general belief is that if you train to failure, you’ll get both stronger and bigger than if you take your sets just to near failure. Some even take this a step further and argue that you should take sets past failure, using methods like dropsets, assisted reps, or controlled negatives to artificially extend your ability to perform more reps past your normal failure point.
The general argument for this is pretty simple - that training to failure produces better results, and that muscles are most stimulated to improve when they’re already near failure, and you’re squeezing out those last few tough reps in a fatigued state. These last few reps are often referred to as “effective reps”, since it’s believed by extension that most other reps aren’t terribly effective. Reps near failure are the reps that “count”.
Training to failure also has another useful quality - it makes it very easy to intuitively progress your workload and keep your workouts appropriately challenging, without having to do complicated math or carefully add reps and sets over time.
If you’re progressing a bench press in the traditional way, you might record your workouts each time, and then add sets, reps, or weight slowly over time in some systematic fashion. This requires a decent amount of organizational effort - you need to record your workouts and then expend some mental effort to progress them, not to mention having some amount of knowledge about how best to progress a program in the long run.
In contrast, you can use training to failure as a way to intuitively make your workouts hard enough, without bothering with any of that effort. If you show up, put a given amount of weight on a bench press, and then just complete 3 sets to failure, you know that your workout is always going to be the a pretty goo level of challenge - because by definition, you’re always training right to your limits. As you get stronger, you’ll just naturally find yourself hitting more sets, more reps, or more weight, with minimal effort to organize your program.
Another cool feature is that, when taken to failure or near failure, we seem to get similar amounts of muscle growth no matter how much weight you’re using - meaning that you don’t have to worry too much about the weight on the bar, either.
Many old-school training programs like HIT are based around the intuitive nature of training to failure - and make it a primary feature.
Training to failure, however, has a few problems and features that you may not know about - some of which should be carefully considered when implementing it in your own training. Here are a few.
When training to failure or near failure, you can expect that form will start to fail a bit. This is less of a problem at lower intensities, where the absolute demand for force is low, and even when your body is struggling to recruit enough motor units to complete the lift, it may still be able to do so without much issue. But at higher intensities, approaching your 1RM, it may not be an issue of recruiting enough motor units - all of your motor units are already recruited, and may not be enough for the task at hand.
On its own, perfect form isn’t necessary. But when this happens, failure to complete another rep will also often mean 1-2 reps with very poor form before you get there, especially on certain lifts which are less dependent on good form to complete the lift. You may also experience shaking and instability at near-max intensities, like the shakiness that often occurs in a very heavy deadlift.
Is form breakdown a bad thing? Yes, it can be. If your form breaks down and this causes the lift to place stress on muscles not normally used by the lift, they may not be prepared for the task, leading to the possibility of strain or injury. Complete and catastrophic form failure may mean dropping a bench press on your chest, or getting pinned in the hole on a squat.
When you’re handling a lot more weight (such as when you’re a pretty strong powerlifter, or one who trains for geared lifting), the consequences for a failed rep can be a lot more severe. If you fail a bench press at 135lbs, chances are you can get out from under it without too much issue. In contrast, a failed bench at 600lbs will mess you up pretty quickly for sure, unless you have a team of spotters to scoop the bar off you as soon as possible. As we can see, the problems with form breakdown when training to failure increase with the amount of weight (either absolute or relative) that we use.
Form breakdown is especially a concern when training for strength, where you want your reps to be as clean as possible. Regular training with bad form will likely hamper your strength in the long run, forcing you to retrain a new movement pattern later. With power-focused movements like jumps and Olympic lifting, training to near-failure can be a much bigger problem, and needs to be avoided entirely unless you’re doing very low intensity training or if you have to, say, because you’re training for CrossFit.
One study found that regularly training to failure led to decreases in both power and strength compared to a program where lifters kept a few reps in reserve - again, evidence that training to failure is a serious problem where strength is involved.
So while training to complete failure may not be much of a form issue at lower intensities (below about 70-75%) or when training for size, it’s probably not a good idea to train to complete failure at much higher intensities or when training for strength. In particular, powerlifters have long argued for the value of not missing reps in training, and of being sure to keep a rep or two in the tank in order to prevent form from deteriorating too much.
Doesn’t Provide Superior Results
While we used to believe that training to failure provided superior results to not training to failure, this has actually been mostly overturned by current research. What we’ve found instead is that training to failure is NOT uniquely beneficial, and in fact provides very similar results to training to near failure (leaving a few reps in the tank).
This does make sense, and still jives a bit with the idea of effective reps that some people use when explaining how training to failure might work. If the last few reps in a set, the ones which feel the hardest, are also the ones that drive the most growth, then we certainly still want to get close to failure. However, this research suggests that training to absolute failure is not necessary - it’s fine to aim a rep or two short while still reaping the benefits of the “effective reps”.
Fatigue and Recovery
Recent research has also shown that training to failure also has another significant problem - that it’s much harder to recover from than training to near failure. On a training program where exercisers were taken to full failure, it took about 48 hours longer for them to recover over the following week, creating disturbances in their training schedule. The trainees also saw higher markers of muscle damage without corresponding increases in size.
This is probably the single biggest reason why training to failure must be done sparingly. While it may make sense to use training to failure as a kind of “intuitive training” where you don’t have to think very much about it, this would only really work well with less frequent training sessions, where recovery between sessions is less likely to be an issue. When you’re training frequently, and your recovery has to be carefully managed to avoid overlap, you definitely want to aim for a shorter recovery time.
Since carefully managing your programming and training frequency in order to get in increasing volumes of work over time is the name of the game, training to failure is probably not an optimal approach for more serious exercisers, who need to carefully organize their schedules around their training and recovery in order to continue to improve consistently.
And even then, this doesn’t render training to failure completely useless - it just means that you have to use it carefully in order to get its best benefits and avoid having recovery issues that threaten your long term progress. For some, smart and infrequent use of training to failure within a training week or cycle may enhance your results a bit.
However, since training to failure generally doesn’t provide superior results (as explored above) - there’s little reward for really grinding yourself to bits on a difficult program where you frequently train to failure, especially if it also comes with the price of slower recovery.
The old bogeyman for training to failure has always been injury risk - with many arguing that, while training to failure may produce better results, it also increases your injury risk significantly.
I don’t agree, and neither does the research, which suggests that at the very least, training to failure doesn’t seem to be any more or less likely to cause injury than normal training. That said, as mentioned above, it may be only very slightly more likely to cause issues, due to the possibility of serious form breakdown.
I’d say that injury risk alone is probably not a major concern when considering what to do about training to failure - instead, it’s probably far more important to focus on recovery issues, which are much more immediate anyway. Poor recovery over time may be a major contributor to injury, but you should worry about that recovery problem more than the injury that it can possibly cause.
(For more on how we get injured, I recommend checking this post out.)
Bad At Estimating Failure
Some interesting research shows that untrained lifters are exceptionally bad at estimating how close they are to failure. These lifters were asked to report what they thought their 10RM was, and then were given assistance and pushed to absolute failure. What they found was that many people who thought they were training “to failure” were in fact several reps away from failure, with many being able to complete 16-20 reps with what they thought was their 10 rep max.
This isn’t necessarily a criticism of training to failure itself. If a lifter is bad at estimating their limits, this doesn’t mean that a program focusing on training to failure is a bad program - just that they’re not suited for it.
However, it’s definitely something to consider. We can expect that more experienced lifters have a better sense of their actual limits, and will be more likely to accurately estimate what true failure looks like, and thus get serious results from training to failure.
And to further complicate things, as explored above, you don’t need to train all the way to failure to get similar results - so, if beginners are seeing good results from training “to failure”, this is actually a good thing and an example of the program seeming to work as intended.
Used To Match Effort
One interesting takeaway from modern research is that, so long as the number of sets to near failure is equated, trainees seem to gain muscle at roughly the same rate. This means that it doesn’t matter too much what intensity you’re training at, so long as you’re training to failure.
Now, this is kind of intuitively known or implied by the high intensity/training to failure advocates, who generally place less emphasis on exact training intensities since training to failure maxes out your intensity at a given weight anyway, but it’s nice to have that validation by the science.
This means that in many cases, the total number of sets taken to near failure for a given muscle group, in a given program, is a pretty good rough estimate of how effective a program will be. This takeaway can be used even in programs where the primary training goal isn’t training to failure - and you can use it to either get an idea of how good a training program is, or as a method of progressing a program over time yourself.
So if this week you trained using 10 total near-failure sets for a given lift over all your training days, and next week you do 11 or 12, you can expect to improve. Thanks to specificity, you’ll still want to use higher absolute intensities when training for strength, but if the goal is muscle mass, you can have some fun and mix up the intensities a bit to give your training some variety.
Not So Good At High Or Low Intensity
One problem with training to failure happens when we work with ultra-high rep ranges.
I remember when I used to enjoy doing very high reps of squats as a fun way to get in some leg training - loading up a bar with just a very small amount of weight, and then doing 50-100 reps. This kind of training was very exhausting and seemed effective, but very often it was hard to tell exactly where my limits were - could I hit 100 reps with this weight, or 101? Often, by pausing a bit between reps and getting an extra breath or two, I could squeeze out another rep or two - and repeat for quite a while.
Sometimes, the real reason I gave up was more about willpower than anything else. Once, when attempting to see how many bodyweight squats I could get out, I managed to get about 250 in about 15 minutes before just giving up out of total exhaustion.
Likewise, once, I attempted to see how many kettlebell swings at 35lbs I could complete in a single day. I prepared food ahead of time, scheduled away a Saturday, and spent about 13 hours alternately watching television and doing swings in my living room until I passed out from exhaustion. While I was never able to hit a real “failure” wall, I could generally only hit about 100-200 reps at a time before I rested, simply because it was hard to focus on counting. Then, with a 10 minute break, I’d be ready to go again.
The problem with training to failure at lower intensities (below 50% 1RM or so) is that while you can still do it, it’s much harder to figure out exactly where “failure” is. When failure more likely means metabolic failure than actual muscular failure, we can assume that the lift isn’t actually recruiting all your muscle units at once, and that you’re not actually getting the full training benefit out of training to failure.
Worse, these types of sets tend to be way more psychologically exhausting, as I explored above. A single set of 10 or 15 to failure may only take a minute or so and not be too psychologically challenging, but a single set of 50 may take upwards of several minutes and be totally exhausting. This makes it a lot harder to fit into a proper training program, and needs to be used sparingly.
Likewise, the research supports this, with the suggestion that higher rep sets to failure are more exhausting than lower rep sets to failure. This study only used failure sets with as many as 12 reps, but still found that the higher rep failure sets were more exhausting than the lower rep ones.
Very high rep sets may have a place in your training - but it shouldn’t be one of your primary training methods. I use high rep sets as a way of testing endurance progress for many of my clients, but I don’t use it as a primary training method - and it shouldn’t be.
Tying It All Together
Does training to failure have a place in a good training program? Absolutely. Is constantly training to failure the best training program? Probably not.
While training to failure is a good strategy in many cases, constantly training to failure is probably holding you back and leaving a lot on the table. Learning to strategically know when to train to complete failure will probably serve you a lot better. In general, training to failure is a good idea when testing your limits or more consistently when training for size, but is less appropriate when training for strength or endurance.
You can probably make your training a bit easier than you think, while still seeing great results. What matters a lot more is that you keep training, and don’t sweat the details too much.
About Adam Fisher
Adam is an experienced fitness coach and blogger who's been blogging for 5+ years, coaching for 6+ years, and lifting for 12+ years. He's written for numerous major health publications, including Personal Trainer Development Center, T-Nation, Bodybuilding.com, Fitocracy, and Juggernaut Training Systems.
During that time he has coached hundreds of individuals of all levels of fitness, including competitive powerlifters and older exercisers regaining the strength to walk up a flight of stairs. His own training revolves around powerlifting and bodybuilding.
Adam writes about fitness, health, science, philosophy, personal finance, self-improvement, productivity, the good life, and everything else that interests him. When he's not writing or lifting, he's usually hanging out with his cat or feeding his video game addiction.
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