Do You Need to Lift Until Failure?

There seems to be some controversy about if you should lift till failure during every set.  Some people say that you always have to lift until you can’t push out another rep, while others say that it is not necessary to go to failure every set in order to gain muscle.  So who is right?

Well first off, let’s make sure that you are going to the gym for the right reason…

When you go to the gym, your goal for that lifting session should be to either:

  1. Gain more rock solid muscle mass or increase your strength
  2. Preserve your muscle mass (assuming you are on a calorie restricted diet)

Your goal when lifting should not be to lose fat.  This is done through dieting and cardio, not lifting.  A lot of the time the people who advocate not going till failure are thinking of lifting as a way to lose fat.

So now that we’ve established that you are basically looking to gain muscle and/or strength, should you go until failure to achieve this?  Moreover, should you go until failure for each and every set?

To determine this, let’s take a look at what actually happens to your muscle during a set:

When you first start your set, you feel pretty strong. Hopefully you have warmed up and your muscles are ready to start firing.  When you start lifting the weight, your body starts using your slow-twitch muscle fibers (ST) to do the work (unless the weight is heavy enough to be in the 1-8 rep range).  This is because they can last the longest and have the most amount of “energy” because they rely more on your aerobic metabolism, which gets constant energy from the air you breathe and your fat cells.  However, your slow twitch muscle fibers are not very powerful and don’t grow very large, so you do not want to focus on these fibers.  If you stopped lifting after just a few reps, you would be targeting mostly slow twitch fibers and never really see much growth.

When your body realizes that you need more power than the slow twitch muscle fibers can provide (by either approaching failure or using a heavy weight), it starts to turn to the fast twitch fibers (FT-A and FT-B, or Type IIa and Type IIb).  FT-A starts to get used first, and the power output of FT-A is in-between ST and FT-B.  FT-A can also last longer than FT-B, but not as long as ST.  FT-A are used for the majority of your set, until the very end (unless your reps are very low, like 1-5, with a very heavy weight. In this case, FT-B might be used most.).  FT-A fibers are likely the best fibers to target for growth. This is because they have been shown to have a high growth potential and can perform a lot of “work”. FT-B fibers, while stronger and “harder”, are more glycolic. Very glycolic fibers like FT-B do not have many mitochondria in the cell (so they run out of ATP quickly) and they have a somewhat lower growth potential. A high proportion of FT-B fibers might be one of the reasons why powerlifters, while stronger than same-weight bodybuilders, have less muscle mass on average.

By the time you get to the end of your set, your FT-A fibers are starting to poop out. Your body will finally bring in the FT-B fibers as a last resort to get maybe the last rep or two. Remember that if you are using a very heavy weight where you would fail at most at 5 reps, then FT-B will come into play much sooner, and likely from the first rep. If you are performing a bodybuilding-type set, then FT-B might only come into play at the very end.

Alright, now that we got all that covered, let’s get back to our question:  Do you need to go to failure?

Well, you should probably be able to see by now that if you do not go till failure, your FT-B fiber will not be used as much as it could be if you are using higher rep ranges, but your FT-A fibers will still be mostly exhausted.  So if you stop 1-2 reps short of failure, your FT-A fibers might still grow, but probably not FT-B a whole lot.

Therefore, you would get bigger and stronger, but possibly not as strong as you could have gotten if you went to failure.

This is a problem because if you continue to do this then you might eventually reach a plateau and stop growing.  There is a limit to how much increase in size you can have without an increase in strength and vice-versa. Though this limit is fluid, strength gains will never hinder future size increases.

A lot of people might actually do this unconsciously, not pushing themselves as hard as they really can.

Getting stronger will allow you to use heavier weights and, by doing so, further increase the damage and growth of both FT-A and FT-B.


There is a trade-off in going to failure. It can limit the total amount of work you are able to do in each session. For example, if you start bench pressing and hit absolute failure after 10 reps, for example, then you might be so exhausted that you will only get 5 reps on your next set (unless you weight a long time between sets, but this has been shown to not be good for hypertrophy). If you only went to 9 reps the first time, you might have gotten 7 or 8 the next, which would increase the total volume of the workout. This would independently increase the signal for muscular adaptations.

So in the end, should you go till failure? Yes, you should.  You should just not always go to failure. Some good examples of this compromise would be only going to failure during the last set of each exercise or only during the last few sets for whatever muscle group you are working. It is a very individual thing, though. Sometimes I can go all-out on the bench press, fail at 10 reps, and a minute later get 8 or 9 reps. In this case, the going to failure was not detrimental to subsequent volume. You need to judge this for yourself, but a good rule of thumb is that the more of a beginner you are, the more you should save failure for the last set only. If you continue to train with shortening rest periods or high volume training, then you might be able to get away with pushing yourself more.

Just remember: No one ever became super-huge with a great physique by NOT giving it their all.

As a last note: if you are performing sets in the rep range of 1-5, then going to failure does sort of become optional at this point. This is because, since the weight is so heavy, the fast-twitch muscle fibers come into play right from the beginning. Also, since the weight is so heavy, going to failure on the first set of these might take such a large blow to your nervous system that you can hardly lift anything on your subsequent sets. In this case, it would probably be to your advantage to stop just short of failure so that you are able to, in the end, perform more total reps with that heavy weight and do more total Work.