Where Do Gainz Come From?

Pop quiz: What's better for gaining muscle size?

  1. Performing technically sound, explosive reps on the big basic lifts, without having to grind out reps, thus maximizing force production and improving both inter and intra-muscular coordination. Or...
  2. Training to muscle failure with moderate weight.

Well, choice 1 has always been the cornerstone of my training philosophy. Why? Because explosive, technically sound reps on the big basics will stimulate maximum strength development. And gaining strength is essential to gaining size. But I've been forced to rethink my stance.

When it comes to training to muscle failure, I used to think we should avoid it. But now it's clear that maximum muscle growth may be impossible without it.

The Muscle Trigger

A recent study found that when it comes to hypertrophy (muscle growth), if you go to muscle failure the weight used doesn't really matter. The same amount of muscle growth and protein synthesis occurred with 3 sets to failure using 30% and 3 sets to failure using 80% of your maximum load.

What does that mean? Training to muscle failure, regardless of the load, leads to a maximal recruitment of muscle fibers.

Shocked? I was. It's not so much the value of training to failure that surprised me, but rather the fact that when it comes to stimulating hypertrophy, the act of reaching muscle failure might be the MAIN trigger for growth. Not the weight lifted or the explosiveness used, but the muscle failure itself.

The Science

Here's a closer look at the study:

  1. Three sets to failure with 30% of 1RM resulted in equal hypertrophy gains as three sets to failure with 80%. This indicates that the weight used isn't the main factor for stimulating muscle growth. If it were, the 80% group would have achieved more results.
  2. Three sets to failure at 80% led to about twice the gains as one set to failure with 80%. This might seem to indicate that volume is important for hypertrophy. But the fact that three sets at 30% led to the same gains as three sets with 80% shows that volume itself isn't the main reason for the hypertrophy.
  3. The lifters using only 30% to failure obviously got a lot more reps per set than 80% to failure, yet both groups had the same hypertrophy response. So volume or the number of reps done per set can't be the reason for the hypertrophy stimulation.

The True Trigger of Muscle Growth

The act of hitting failure – and not the accumulation of muscle fatigue – would seem to be the trigger for growth. So you can't simply do more work to get more growth if you never reach the point where you trigger max hypertrophy. This means reaching failure on a set is likely the actual trigger for optimal growth and protein synthesis.

In the study, having three "failure triggers" caused more hypertrophy than having only one failure trigger. And as long as you had those triggers, the hypertrophy was the same regardless of the weight lifted. So if you're training for size gains, the load doesn't really matter. And by the same extension, there's no longer any burden to have to increase the weight from session to session or do more reps for hypertrophy, as long as you reach muscle failure.

If you're a dedicated lifter, you likely won't want to use 30%. You'll either become bored or fall asleep way before reaching failure. But being able to choose how heavy you go gives you freedom. When doing an exercise mainly to build muscle mass, you can select the weight that allows you to feel the muscle working the best. You'll find a sweet spot where a weight feels just right.

Sure, you can lift more (sometimes a lot more) but despite using more weight you won't feel it as much in the target muscle, which means you won't feel the same contraction quality. And if you go too light you also don't feel the contraction as much.

Now that we don't have to fixate on adding weight from session to session, we can focus simply on reaching failure with the weight that feels the best on the muscle. Even if it takes you several workouts to add more weight, it doesn't matter as long as you reach failure. Just increase the weight when a load no longer feels right for the muscle.

Think Failure, Not Fatigue

To be clear, let's define failure: Reaching a point where you attempt to lift a weight after having performed some amount of mechanical work (reps) but can't do it despite trying very hard.

It would seem that the act of hitting failure is the main stimulus for growth. Something happens when you attempt to lift a weight (that you were able to lift several times just seconds prior) that sends a signal to the body that it needs to adapt. The failure of accomplishing a task that you were capable of doing seconds before is the "trigger."

Now, don't dismiss the value of mechanical work. Consider taking this idea to the extreme. Let's say you take a weight that you can barely lift once. After that first rep you attempt a second rep and fail midway. Sure, you hit muscle failure, but it's doubtful that this approach will stimulate maximum hypertrophy. So while muscle failure is the main trigger for growth, a sufficient amount of mechanical work has to be performed prior to hitting failure in the set to stimulate the best results.

So, What's the Best Load for Gains?

The study compared 30% to 80% of 1RM and found the same amount of hypertrophy occurred if failure was reached. So is there a specific load that you should use, or does it really even matter?

First, don't think that going above 80% will give you better results hypertrophy-wise. In fact, going too heavy will lead to less muscle growth when using the failure model. If you use too much weight you won't precede muscle failure with enough mechanical work (reps) to maximally activate protein synthesis.

I also doubt light weights in the 30-50% range would be optimal for normal, healthy lifters. It might be a valid way for injured individuals to train though. Healthy, experienced athletes might actually have a hard time getting the most out of a 30-50% weight because the early reps won't feel right. You won't get the same muscle tension as with slightly heavier weights, though in theory it won't matter as long as you reach failure.

But when the first part of a set doesn't give you fast enough feedback of feeling tension it's easy to lose focus. And as a result, you may find yourself going through the motions rather than producing the same high-quality muscle contractions during the set. This reduces the efficacy of each rep and the likelihood of hitting real muscle failure. You'll hit psychological failure instead.

For most people, the 60-80% range would be optimal when training for hypertrophy using the failure model. That would come up to about 8 to 15 reps prior to hitting muscle failure.

And as long as you stay in that zone and hit failure, the hypertrophy results will be the same. So you don't have to figure out the perfect percentage, and you don't have to add more weight every session. You could even use 80% in the first session, 65% in the second one, 75% in the third one, etc. and get maximum muscle growth each time.

The most important factor in load selection is choosing a weight where the muscle tensions feels right from the first rep. Heavy enough to feel a lot of muscle tension, but not so heavy that you lose tension in the target muscle group because you're compensating with other muscle groups, or shifting tension to the connective tissues.

What About Strength?

Training to failure with moderate weights can build strength. After all, even Westside powerlifters use the repetition method with sets of 12, 25, and even 50 reps per set on some movements. They wouldn't do it if it did nothing for their strength.

When you do failure work with lighter loads you can increase the strength of the muscles trained, but if you want to be strong on certain lifts it's essential to practice doing these lifts with heavy weights. Lifting heavy weights isn't just about muscle strength; it's also about neural efficiency.

Even though going to failure will recruit the most fibers during the set, it doesn't mean that the intra-muscular coordination (making those fibers work together to produce max force), rate coding (having the muscle fibers fire at a fast rate), and rate of activation will be optimal to perform a lift with maximal or near-maximal weights.

Being able to produce force with a muscle is a general physical quality, but being able to use that capacity to perform a heavy feat of strength is a skill. This needs to be trained.

Bodybuilder Training

The Problems With Training To Failure

1 – It's draining.

It can be too draining to do on big compound movements. Is going to failure on back squats, deadlifts, push presses, or power cleans really a great idea?

The overall stress impact of one big set to failure on these exercises will be very high. Now imagine three sets, which seems to be the optimal number! The metabolic demand might be enough to kill your capacity to work hard for the rest of that workout, and could also impair the amount of frequency you can use during a week.

2 – It needs to be done in isolation.

The methods aimed at targeting the nervous system (heavier or more explosive lifting) and the methods aimed at stimulating muscle growth (failure training) should not be done at the same time on the same exercise. Failure training is best used with isolation exercises or on machine movements which are much less demanding on the nervous system.

3 – It's not optimal with compound lifts.

The big compound lifts aren't the best option for failure training because you will rarely, if ever, hit muscle failure with any one muscle involved. It's not about failing a movement. It's about failing to contract a muscle hard enough to continue on with the set. But people tend to see failure as movement failure, the "go until you can't do another rep" failure. They focus on getting reps instead of causing muscle failure.

What's the difference? Two things: First, you can compensate by adjusting your body position during the set, thereby using other muscle groups when the target muscle starts to fatigue. You think you're stimulating it more by doing more reps but you're actually stimulating it less by allowing other muscles to do the work.

Second, you use the minimum effort possible for each rep to be able to do more, instead of trying to contract the muscle as hard as possible on each rep. If anything, you should be proud to achieve muscle failure in fewer reps – it means you're doing a better job contacting the muscle to produce more tension on each rep.

So if we go back to our compound movements, going to failure rarely means that you achieved muscle contractile failure. You only achieved movement failure.

In reality, it's likely that no muscle involved in the big lift has hit failure. Rather, it's the ensemble of muscles involved that can no longer produce enough total force to complete a rep. The fatigue is spread over many muscles; it's not one target muscle that hits failure. Compound lifts are thus better suited for heavier lifting: practicing producing force against a high resistance, which should be a part of any training program.

4 – It's easy to "fake" failure.

There's also a possibility of faking yourself out and not being able to achieve muscle failure. We've all faked ourselves out at some point: stopping a set when we "created" failure, while it would've been possible continue on a bit more. And some simply can't tolerate the discomfort of training to failure. If you use a system based on training to failure and you can't really achieve it, then you won't get the benefits of the program.

5 – You can't use high volume.

Training to failure is much more demanding than stopping just short of it. As such, you can't perform the same amount of volume as you would if you were using a regular bodybuilding routine where you stop just short of failure.

Three sets seems to be best for an exercise. And a total of six sets for a muscle group would be all that the muscle could handle. In most cases it might even be too much, or unnecessary, assuming that you indeed reach real contractile failure. For that reason it would be easy to overdo the amount of work performed and limit your positive adaptations.

What About Extending A Set?

If failure is the trigger for maximum muscle growth, then it's tempting to ask about taking a set past the point of failure. That is, reaching muscle failure on an exercise then using a method that would allow you to extend the set so you can reach failure a second or even third time in the same set, like doing drop sets or using the rest/pause method.

Would this cause even more growth? Maybe, but the trigger is the act of failing, not accumulating more and more fatigue. So doing more work in the set wouldn't seem to contribute to stimulating more growth, but failing several times in a set might make that set more effective.

On the other hand, extended sets are much more demanding than regular sets. So if you do that on every set during every workout, you have a good chance of doing more harm than good.

Extended sets are very effective, but only when performed on the last set of an exercise and not in every workout. And certainly don't use extended sets to compensate for not reaching the failure point. It's much more important to work on improving your capacity to reach muscle contractile failure then to do more work via extended sets.

Final Reminders

Heavy work on the big basic lifts is still important for anyone wanting both strength and size. There's no doubt anymore that exercises performed to failure are a valuable addition to hypertrophy training. Optimal muscle growth might not be possible without it. Just remember that if both types of training are included in your program, they shouldn't be done at the same time. They're separate tools to be used to complement each other.

Note: Special thanks to Dr. Stuart Philips and Dr. James Steele for their contributions here.

Related:  5 Secrets of Building Muscle

Related:  The New Science of Time Under Tension


  1. Cameron J. Mitchell et al. J Appl Physiol 2012;113:71-7