Is planning to fail a failure to plan? We get the definitive facts from one of the world’s foremost experts so you can apply cutting-edge science to your workouts today.

Is failure an option?

Failure training is probably the best way to cause muscle growth in any given training session. However, training to failure also causes a disproportionate level of fatigue, so if you want to have two very productive training sessions in a row (let’s say a great upper body workout Monday and then again on Thursday), then the first session (Monday) should probably stay perhaps 1-2 reps shy of failure so that it can be productive, but not cause so much fatigue buildup that the session after it (Thursday) cannot also be as or even more productive.

The way we make our best long-term muscle gains is by stringing together multiple (3-8) weeks of sequential training which gets harder over time. In order for such an approach to work, we need to make sure we only save the very last sessions of such a stretch for training to failure, and keep the earlier weeks’ sessions to perhaps as many as 4 reps away from failure.

Maybe an ascending process can be followed, where early weeks see training that is kept 4 reps shy of failure, later weeks 3 shy of failure, then 2, and then finally, in the very last week or two, we go hard enough to leave only 1 rep in the tank or hit true failure itself. Then we de-load, and repeat the process. This way we’re likely to get the benefits of failure training within the grand scheme of a progressively overloading training regime.

Is it an outdated practice? No, not so much outdated, but updated. Going to failure every session as a near-religious practice is certainly outdated. But going to failure strategically on occasion to grow muscle, and mostly staying a few reps short is a very good and empirically-confirmed idea.

Failure under the microscope

Nothing overly special happens when you fail that doesn’t occur in every other rep. It’s just that failure happens when muscles get so fatigued they cannot lift the weight you’re using. This comes with extra eccentric overload and thus muscle damage if you “ride the last rep out” by still trying to slow it down as much as you can, but a rep’s worth of that isn’t much in the grand scheme.

That being said, the closer you get to failure (especially when you’re within 5 reps or so from it), the more all of your muscle’s machinery becomes active and thus benefits from a training effect. This is especially true with weights lighter than your 10 rep max, because some of the biggest and strongest parts of your muscle (motor units) are just not turned on at all and thus neither contributing force to lift the weight nor benefiting much from the training. When failure is 5 or fewer reps away, pretty much all motor units turn on, contribute force, and likely get a growth stimulus.

So, while there’s nothing overly special about failure itself, getting close to it (or at least not often wandering further than 5 reps away from it) is a pretty important component of causing the most muscle growth.

The drop set effect

Drop sets are a way to get more work in, thus stimulating more muscle growth precisely by letting muscles continue to work close to their failure point. If you go to failure (or even just two reps shy of it) on cable curls, for example, you can keep the stimulus going by lowering the weight by 20lbs and doing perhaps another 3-5 reps with no rest. Every one of those reps is likely to be within 5 reps of failure and thus stimulate nearly all muscle fibers to grow.

Danger: failure notice

First of all, when you’re very close to, or at failure, your technique has a very high chance of becoming unstable. Unstable technique can make you or the bar wobble, and some of those movements will be away from the “safe zone” of motion that your muscles and connective tissues can handle.

For example, if you’re incline benching and you are grinding out the last rep, you might flare one of your elbows out during the struggle. Mostly that’s not going to be a problem, but on some occasions this elbow flare will be a couple of degrees too far for your shoulder joint, and an injury might result.

The second danger of training to failure is the answer to the question “who is going to catch you or the weight when you physically can’t lift it anymore?!” Sure, going to failure on cable triceps pushdowns is perfectly safe in this regard because you just ride the weight back up nice and slow when you hit failure and no harm, no foul.

But if you’re squatting, failure is a big deal! Even if you only squat a hundred pounds or so for reps, that’s a heck of a lot for a spotter to lift as your technique breaks down and you keel over. If you’re squatting over several hundred pounds, forget about it.

Spotters are there to make sure you don’t kill yourself, not to drag you out of a hole at the end of every set. And the leg press? You’ll be at serious risk of grotesque injury if you go to true failure on that machine and you’re not a Quickdraw McGraw with the safety handles.

If you’re going to go to failure, make sure you can keep your technique stable and only do it on exercises or machines that don’t risk your life and limb if you can’t move the weight anymore.

Failure is not for everyone

Beginners have very unstable technique, and going to failure not only risks them injury more than it does the experienced lifter, but it can actually teach them poor technique, because that’s what they will be practicing often if they get close to failure all the time in their training. And the kicker? Beginners grow so fast they don’t remotely even need the “5 from failure” practice to make great gains.

Once someone is past the first 6 months or so of training at least, individuals can begin to get a bit closer to failure. Secondly, the elderly and individuals who are more injury-prone or have balance problems should avoid failure or getting close to it.

Kind of a no-brainer, and this includes individuals recovering from injuries in the utilized area. For the average guy though, unless you’re very unstable during the last few reps, failure training doesn’t have any negative effects on joints.

A safer approach

On average, training about 2 reps shy of failure gives almost the same benefits as failure training, but with much less downside. Quite a few folks will want to train to failure so they can “really feel” the workout, but that’s nothing that can’t be solved with just adding one or several more sub-maximal (shy of failure) sets. If you’re used to hitting failure with 4 sets of leg extensions, for example, doing 6 sets of extensions 2 reps shy of failure each will have you “feeling it” just fine!

Not all muscles are equal

Some muscles are faster-twitch than others so they fatigue more quickly. This means that for any given rep range, they will be more likely to fail. For example, the gastrocs (the diamond-shaped part of your calves) are usually faster-twitch muscles than the soleus (the longer muscle underneath the gastrocs). So, if you do standing calf raises and go to failure, your gastrocs will almost certainly give out first.

A big deciding factor as to what’s going to fail first in a multi-muscle system is the degree to which a muscle is being taxed compared to others.

For example, in the pulldown, grip usually goes first because you’re asking small muscles like those of the forearm to keep up with huge muscles like the teres major and lats in your back. In stiff-legged deadlifts, the hamstrings are at a mechanical disadvantage and thus fatigue much faster than the glutes. In close-grip bench pressing, the triceps might be tasked with more work than the pecs and thus fail first, and so on.

The mental handbrake

A certain amount of fatigue, especially acute fatigue (how many more reps you can do in a given set), is regulated by the brain. If you’re mentally tougher (a skill than can be developed by months and years of practice lifting weights, for example), you can go further in a set than if you’re less tough. So, when you’re able, you can push yourself further than what you might have thought possible.

The idea that your brain is the dominant determinant of fatigue is called the “central governor model” of fatigue.

It’s definitely true in part. Your brain does limit your performance, especially in endurance activities, where it can make a very big difference in acute fatigue. On the other hand, it’s by no means the only source of fatigue. Muscle damage, hormonal alterations, and a host of other factors have been very well demonstrated to factor into fatigue, especially of the cumulative type.

So yes, if you can overcome central fatigue, you can go beyond your usual failure point. If you go there with forced reps, you can get a little bit more muscle growth stimulus from that session. But then you’re left with much more muscle damage and other kinds of fatigue that will limit you even more in the next session.

My best recommendation is to stay mostly shy of failure, perhaps starting a training cycle 4 reps shy or so, and getting closer to failure with each week until the last week has you going to true failure on the kinds of exercises that allow it and close to failure (1-2 reps) on the kind, like squats, where you’re far better off staying away from failure.

Failure in practice

Your playbook for pushing your limits the right way

A) Consider your time constraints

If you only have 20 minutes per session to work out and only four sessions per week, you should probably train every single working set to failure. You want maximum benefit and you won’t have to worry about fatigue.

B) Think of recovery and volume

In a similar vein, if you only train for six or fewer working sets per muscle group per week, in many cases, you won’t have to worry about cumulative fatigue and you can just train to failure each time. Ideally, doing more training and being a bit shy of failure would be best, but if you can’t commit to such a program, going to failure more often is the next best thing. Lastly, if you don’t have to be recovered for a while, you can go to failure or very close to it. For example, if you’re about to do a de-load week, you can definitely go to failure in the week before because you’ve got double the time to recover.

C) Factor in exercise safety

If the exercise can hurt you or worse if you fail, don’t go to failure on it, and stay 1-2 reps shy at most and with a spotter or two close to hand.

D) How much muscle mass is used?

Bigger muscle-mass exercises fatigue you a lot more if you take them to failure than smaller muscle-mass exercises. For example, shoulder presses taken to failure often can really beat you up, but triceps extensions can be more tolerable when taken to failure. If you want to go to failure or close to it often, save this for the smaller muscle groups like biceps, calves, triceps, and maybe side and rear delts. Chest, quads, glutes, and back will fare better by being trained to failure less often.

TRAINER: Dr. Mike Israetel

Team USA Weightlifting Consultant co-founder and chief sport scientist of Renaissance Periodization (