Some coaches believe you should always keep 3-4 reps in the tank, and some coaches believe you should train your muscles to failure…
… but who is right?
Well, if your goal is to build muscle research indicates that failure is the way to go.
When applied correctly, training to failure can significantly boost your results in the gym, and have your pals wondering what the heck you’re doing (or what you’re using!) to see such progress, but when applied incorrectly it can be a serious waste of time (or even worse, it can lead to injury).
Let’s break it down.
Table of Contents
- What Is Training To Failure?
- How Does This Help You Build Muscle?
- The Science Behind Training To Failure
- Don’t Just Hit Failure… Do It Often!
- High Rep Sets Must Be Taken To Failure
- How To Train Beyond Failure
- Get More From Russ!
What Is Training To Failure?

Training a muscle to failure means reaching a point of being unable to perform another good rep.
As an example, if you’re performing a set of 8-12 reps, think of those last couple of reps where you’re struggling to get the dumbbells through a full range of motion; that’s failure.
We can also apply this method to high rep work, so if you’re shooting for 20-30 reps, think of the moment where “the burn” kicks into over-drive and you’re struggling to lift those tiny 2.5kg dumbbells; that’s failure.
How Does This Help You Build Muscle?

Training to failure will elicit a greater anabolic response from your body, and this makes it possible for you to build more muscle.
It’s not only about how much weight you managed to lift, instead it’s about spiking the release of certain anabolic hormones. You’ll see a rise in testosterone, cortisol, growth hormone, and insulin-like growth factor-1; all of which are key players in the hypertrophy process. (10)
This creates a superior environment for muscle growth.
The Science Behind Training To Failure

The first study to show the benefits of training to failure actually did it by accident.
Back in 2010, a team of researchers from McMaster University, Canada, set out to discover the different anabolic responses caused by heavy weight and low volume training versus light weight and high volume training. They had participants train like this:
- Group A: 4 sets of 4-5 reps
- Group B: 4 sets of 20-30 reps
- Group C: 4 sets of 20-30 reps with an easy weight (control group)
In terms of the research they were looking for, Group B saw greater muscle protein synthesis than Group A so this was the first study to show that higher rep ranges can be very useful for building muscle, but they also discovered that Group C (the control group who did not train to failure) recorded significantly worse results than either of the other groups. (1)

One year later, researchers from the same university decided to do a follow-up study on using high rep training for muscle growth.
The methodology was the same:
- Group A: 4 sets of 4-5 reps
- Group B: 4 sets of 20-30 reps
- Group C: 4 sets of 20-30 reps with an easy weight (control group)
Amazingly, the results were almost identical!
The researchers were able to replicate the findings of original study, with the high rep trainees seeing a larger spike in muscle protein synthesis than the lower rep trainees – and interestingly, we saw again that Group C (the control group who did not train to failure) recorded the worst results of all three groups. Yikes! (2)
This time around, the researchers acknowledged that they believed going to failure played an important role in the process:
“Our results suggest that resistance exercise performed until failure confers a sensitizing effect on human skeletal muscle for at least 24 h that is specific to the myofibrillar protein fraction.”

So now we had not one, but two separate trials showing interesting results by having participants train to failure.
It highlighted the need to investigate this topic further, with more in-depth analysis with more specific methodology.
You see, the first two studies weren’t really set up to test the effects of training to failure. They showed improvements in MPS, which is a solid indicator that your muscle are indeed growing, but what we really needed here is studies which use muscle measurements, studies which are performed over a longer period of time, and studies which have trainees hitting the exact same rep range but with one group training to failure.
We got this in 2012, thanks to a study published in the Journal of Physiology.
This time around, the participants trained as follows:
- Group A: 3 sets of 12 leg extensions with 30% max weight
- Group B: 3 sets of 12 leg extensions with 30% max weight and slow lifting tempo
Slowing down the tempo caused the participants in Group B to reach muscle failure, and they recorded significantly better results than the trainees in the other group, confirming what many bodybuilders have suspected for years – training to failure is GREAT for muscle growth! (3)

Don’t Just Hit Failure… Do It Often!

Now that research was beginning to pile up showing the benefits of training to failure, we saw studies attempting to answer even more specific questions.
One of the first areas to be explored was frequency… how often should you train to failure?
A 2012 study published in the Journal of Applied Physiology tackled this one by having trainees line up as follows:
- Group A: 1 set of 8-12 reps
- Group B: 3 sets of 8-12 reps
- Group C: 3 sets of 20-30 reps
All participants used weights which helped them train to failure, but the key difference is that Group A only did it once. By the end of the 10-week program, Group B and Group C unlocked significantly better muscle building results than Group A, suggesting that not only do we want to train to failure, but we want to do it often! (4)
Obviously, that’s not me saying you should perform every set to failure. I believe warm-up sets and working sets still have a role to play in helping you build muscle and in keeping you safe from injury, but it indicates that you’ll achieve better results by reaching failure multiple times in your workout.

High Rep Sets Must Be Taken To Failure

In the 2010s we began to see studies which showed that high rep sets (15+ reps) can be just as effective as traditional training (8-12 reps) for building muscle.
The one thing all of these studies had in common is that they ALL trained to failure.
(In fact, there isn’t one single study showing muscle growth from high rep training without going to failure!)
So why is it such a crucial component?
Well, it comes back to something called The Size Principle. The size principle dictates that the body will always recruit muscle fibers in order from smallest-to-biggest, so that it can conserve energy wherever possible. (9)
We can exploit this to make your high rep training super-productive!
You see, when you train with a heavy weight and a low number of reps per set, this targets your body’s fast-twitch muscle fibers. These are big, explosive muscle fibers which are very easy to build with heavy training. When you switch to using higher reps and lighter weights, the focus moves to your body’s slow-twitch muscle fibers. These are smaller, weaker, and built for endurance.
This explains why, as a general rule, training with heavy weights for lower reps is an easier way to build muscle. (5, 6)
However, taking your high rep sets to failure will make them just as productive!
To explain how, let’s take a look at what happens inside your body when you lift some heavy dumbbells…
Your body will instantly recruit the small, slow-twitch muscle fibers in the target area to see if they can get the job done while using as little energy as possible. If you are lifting some heavy dumbbells, it’ll quickly realize they cannot handle the weight involved, and it’ll switch to the fast-twitch muscle fibers to get the job done. That’s how low rep training works.
When you are performing a high rep set (15-30 reps), your body begins in much the same way, by recruiting the small, slow-twitch muscle fibers in the target area – except this time they can handle the weight. As you continue pushing out reps, you’ll fatigue those muscle fibers, and the body calls in assistance from the nearby fast-twitch muscle fibers, too, so by the end of the set you’ve FULLY exhausted the muscle. (7, 8)
That’s why you must take your high rep sets to failure to elicit muscle growth.

How To Train Beyond Failure

Here’s where things get really painful!
Those of you with more experience under your belt can experiment with techniques which temporarily take your muscles beyond failure to unlock even better results.
(Yes, it burns like fuck.)
We do by using a series of little techniques I call “Muscle Busters”.
These are nasty little methods which I add into workouts to ensure you’ve got absolutely nothing left in the tank by the end of your set. Doing this will result in an even bigger spike in testosterone, cortisol, growth hormone, and insulin-like growth factor-1, but we need to apply them sparingly to get the best results, because going beyond failure could negatively impact your performance on subsequent exercises if used too frequently.
As an example, if somebody is training chest and they decide to perform four sets each of dumbbell chest press, incline dumbbell chest press, and dumbbell flye, if they took all four sets of the first exercise to complete failure this would undoubtedly force them to reduce their performance on the other exercises which followed. Instead, I recommend performing most of your sets in a traditional manner (set 1 should be used as a warm up, and to grease the groove of the movement pattern of the exercise, and sets 2+ should focus on performing high quality reps, increasing the weight as you go if possible), then the final set is where you want to push the target muscle to failure. Training this way will unlock superior results.
For the russhowepti.com members reading this, that’s why I typically have you apply these methods after the final set of an exercise as opposed to every single set.

“The further you can take a set beyond failure, the higher you can increase levels of these natural muscle building hormones, and the further you can push muscle growth.” – Dr. Jim Stoppani
Here are some of my favourites to use:
- Dropsets
Perform your final set of an exercise then immediately lighten the weight by about 30% and continue squeezing out reps to failure. Job done. Dropping the weight by this amount should let you achieve almost the same number of reps you hit in your final set. (11)
- Rest Pause
Complete your final set, then rest for a 10-count, and then see if you can squeeze out a few more reps (same weight). Your muscles can replenish phosphocreatine very quickly, and the Rest Pause technique allows you to take advantage of that, so you should be able to hit 4-5 more reps even though you only rested 10 seconds. (12)
- Forced Reps
Your ability to perform forced reps at the end of your final set depends on you having a training partner. When you reach the point of failure, have your partner help you to perform a few extra reps. Research from Finland shows that this technique can increase the number of fast-twitch muscle fibers which are recruited, versus stopping at traditional muscle failure. (13)
- Negative Reps
Load the bar with a slightly heavier weight usual and have your training partner assist you during the lift (i.e. curling a barbell up), before letting you control the negative (i.e. lowering a barbell curl) on your own. Most of the muscle building effects of an exercise occur in the eccentric phase, so being able to zone in on this portion of the rep with a technique like negative reps is a sure-fire way to make your muscles feel like they’re being punched in the face with a five-sided fistagon. (14)
I hope you’ve found this article helpful. See below for a selection of training programs I think you’ll enjoy.
References:
- Burd N. A., et al. Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise In Young Men. PLoS ONE. (2010)
- Burd N. A., et al. Enhanced Amino Acid Sensitivity Of Myofibrillar Protein Synthesis Persists For Up To 24 Hours After Resistance Exercise In Young Men. J Nutr. (2011)
- Burd N. A., et al. Muscle Time Under Tension During Resistance Exercise Stimulates Differential Muscle Protein Sub-Fractional Synthetic Responses In Men. J Physiol. (2012)
- Mitchell C. J., et al. Resistance exercise load does not determine training-mediated hypertrophic gains in young men. J Appl Physiol (2012).
- Wackerhage H., et al. Stimuli and sensors that initiate skeletal muscle hypertrophy following resistance exercise. J Appl Physiol (1985).
- Peterson M. D., et al. Progression of volume load and muscular adaptation during resistance exercise. Eur J Appl Physiol (2014).
- Tee J. C., et al. Metabolic consequences of exercise-induced muscle damage. Sports Med (2007).
- Schoenfeld B. J., et al. The mechanisms of muscle hypertrophy and their application to resistance training. J Strength Cond Res (2010).
- Henneman E. Relation between size of neurons and their susceptibility to discharge. Science (1957).
- Krzysztofik M., et al. Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods. Int J Environ Res Public Health (2019).
- Fink J., et al. Effects of drop set resistance training on acute stress indicators and long-term muscle hypertrophy and strength. J Sports Med Phys Fitness (2018).
- Marshall P. W. M., et al. Acute neuromuscular and fatigue responses to the rest-pause method. J Sci Med Sport (2012).
- Ahtaianen J. P., et al. Acute hormonal and neuromuscular responses and recovery to forced vs maximum repetitions multiple resistance exercises. Int J Spors Med (2003).
- Dannecker E. A., et al. Effect of eccentric strength testing on delayed-onset muscle pain. J Strength Cond Res (2005).
Get More From Russ!

I’m Russ. I’ve been a personal trainer since 2002, and I own russhowepti.com.
My job is to simplify fitness so that anybody can get in great shape.
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