Train this close to failure for optimal gains [2 New studies]

Chapters:

00:00 Study 1

02:35 MH Physique App

03:00 Study 2

03:46 Effect on strength vs size

05:54 The “Effective reps” model

06:57 Stimulus to fatigue ratio

08:41 RPE and RIR

10:59 Outro

Transcript:

In the first new study the researchers had a group of strength trained Brazilian women perform a bench press training program to varying degrees of failure. Proximity to failure was standardized by velocity loss during the set. One group trained with a 0% velocity loss, essentially serving as a control group and only performing one repetition per set. One group trained with 25% velocity loss, which is kind of a warm up set for most people, honestly, and one group trained to a 50% velocity loss, which is a more serious set closer to failure.

After eight weeks there was a pretty clear trend that the closer the women trained to failure, the more gains they got. You might note that muscle growth was measured in the triceps instead of the pecs, which you would expect for a bench press training program. However, because women have boobs, that’s kind of an ethical minefield …ultrasound probing that area. The pattern of strength gains similarly showed that the Brasileiras training closer to failure got better strength gains.

I would note that most of the between group comparisons did not reach statistical significance. However, the usual limitations of a relatively short study, and in this case trained individuals with a relatively small sample size, means that it’s very difficult to find statistically significant differences, especially in trained individuals who just don’t gain that much muscle or strength over the course of an eight week program. So overall, I would say these results are very consistent with the idea that training closer to failure improves strength and muscle growth. And you might say that this is a pretty “duh, man on the moon” type finding. 70% higher repetition volume in a group training closest to failure should logically translate into greater muscle growth and strength development, you would say.

However, if you look at the second study we’ll see that this is not always the case. Moreover, this study had one big caveat, which is that the repetitions per set were quite low because they went pretty heavy in some of the weeks. You can see in the table here that the repetitions completed were actually below 5 in many of the weeks leading the average to be very, very low in a group with only a 25% velocity loss. This may not represent normal training conditions for most people, because there are a lot of studies that have found that there was a minimum repetition volume per set, around four repetitions, which is needed to maximize muscle growth.

Another highly notable finding of this study is that the group doing 1 repetition per set still made significant strength gains. Didn’t gain any muscle, but they did gain strength. This shows you why it is so important to have a consistent training program over time, because if you switch up your training program entirely every eight weeks or so, even as a trained individual, your strength gains really don’t mean anything. They are mostly the result of improved neural coordination of your muscle mass, rather than a sign that you’re actually gaining more muscle mass. For strength gains to really reflect muscle mass you need to have an exercise in your program for more than eight weeks.

The second new study had a similar design, but instead of Latinas doing bench presses, they looked at men doing squats. Group of strength trained men did squats to varying degrees of failure: 0%, effectively again serving as a control group, doing only one repetition, 10%, 20%, and 40% velocity loss. For muscle growth the findings were very similar. After eight weeks, while most of the comparisons between individual groups were not statistically significant, the overall trend was quite clearly that training closer to failure led to more muscle growth. For strength gains, however, the trend was that there was more of an optimum curve with worse absolute effect sizes for one arm strength, jump height, and maximal repetition tests in the group training closest to failure. So the gains in absolute terms were the greatest in the 20% velocity loss group, not the 40% velocity loss group.

Now, if we zoom out and look at the latest meta-analysis on the topic, not including the two new studies yet, we see this clear discrepancy between the effect of training to failure on strength and size gains as well. Muscle growth very linearly increases with closer proximities to failure. The harder you train, the more muscle you get. However, strength gains in many studies are almost entirely unresponsive to proximity to failure. Training closer to failure does not reliably improve strength gains, and in some studies even shows a trend for worse strength development.

Physiologically this can make sense because, while strength is also influenced by muscle mass, it’s also highly influenced by neural coordination. Strength gains seem to be very positively influenced by very high force output and very high levels of muscle activity per rep. Going to failure, or very close to failure induces fatigue that lowers muscle activity levels and force output, making it less effective to develop high levels of muscle activity and force output. So for strength development a decent argument can be made that training to failure is at least not necessary, possibly even detrimental, and therefore best avoided in favor of just doing more high quality sets as opposed to fewer sets closer to failure.

However, a big limitation of the literature is that all of these studies are very short term, and in the long term muscle growth significantly improves strength development. For muscle growth it’s crucial to realize that training to failure itself is not what drives the additional muscle growth. We did our own in-house meta analysis of the literature for my online PT course, looking at all the available studies and then splitting them by trained individuals, untrained individuals, volume equated and non volume equated conditions. Here we see a striking difference.

On average training to failure does improve muscle growth compared to not training to failure. However, as you can see here, if we look at studies that are volume equated, so the total number of repetitions is the same in groups training to failure and groups not training to failure, we see that muscle growth is basically identical in both trained and untrained individuals. We see that in multiple studies training closer to failure improves muscle growth, but another group that has the same number of repetitions by doing more sets further away from failure gets the same gains. So it’s the total repetition volume, assuming you’re at least somewhat close to failure, that drives muscle growth, not the fact that you are actually going to failure or closer to failure.

This distinction of why muscle growth increases as you train closer to failure is crucial, because it seriously changes how you should program. There is a popular model, which is “the effective reps” or “stimulating reps” model that as you get closer to failure, it’s the last five or so repetitions of the set that are most stimulatory. And in fact, almost all of your gains come from those last five repetitions. The data do not support this. If you look at the latest meta-analys issues you could see that the trend was basically linear. There was no effect where suddenly the last five repetitions have a very strong effect, and the repetitions before that don’t have any effect. We see that it’s basically a linear effect across proximity to failure, from warm up sets all the way to true failure.

Moreover, we see that in the studies where you equate the training volume by doing more reps, by doing more sets, even when you’re not going five reps to failure, such as seven reps with 12 RM, which is done in multiple studies, you do get equivalent muscle growth. So, it’s not necessary for maximum muscle hypertrophy to get within five reps to failure. Although I would seriously question your training efforts if you’re not going within five reps to failure. This distinction between the effect of training to failure and repetition volume is particularly important when you’re going to true momentary muscle failure, because when you go to true momentary muscle failure, the stimulus to fatigue ratio worsens significantly.

The latest meta-analys of the literature finds that even under volume equated conditions, so even when another group is doing more sets to get the same total number of repetitions that you are by going to failure, you’re still getting more neuromuscular fatigue and extended recovery times compared to the group that does more sets a bit more away from failure. So training for failure is very inefficient. In a low volume training program that is fine, it’s not a problem, but the high fatigue probably limits how much total volume you can productively accumulate. Moreover, within a workout, going to true momentary muscle failure is very inefficient because it often doesn’t actually increase your total rep volume.

Going closer to failure, as was done in the two new studies, but not actually reaching momentary muscle failure, so not literally failing reps, does increase repetitions on average. But if you’re literally failing reps that last rep, which is not even a complete rep, often reduces how many reps you can do in your next set by at least one. That means that the average effect is often zero. So you are expending more effort getting more fatigue, but you’re not getting a higher total rep volume because that one additional rep or that half additional rep that you’re not doing limits your total rep volume in the later sets, which limits how much total time under tension you can accumulate on that muscle group in your next set.

Therefore, the method that I use in my MH Physique app, and what I generally teach to my students in my PT course is to do as many reps as you can, as many reps as possible, without intentionally hitting momentary muscle failure. So you do as many reps as you can, but you don’t actively aim to fail a repetition. When you think that last repetition is not going to be a complete repetition, you don’t do it.

In evidence based fitness, it’s very common to recommend RPE or RIR values. Repetitions In Reserve or Ratings of Perceived Exertion, which are often inverted to still basically become Repetitions In Reserve. I think that this is for many people, a needless overcompensation, because if you just do as many reps as you can then you get maximum muscle growth per set. So it is the most time efficient, it is the most simple, and I think for a lot of individuals, mostly not people watching this video, but especially the less serious lifters, any obsession with RIR values or stimulus to fatigue is detrimental because we see in research and in practice that most people in the gym do not train to momentary muscle failure.

So most people are best off simply told, go to failure or go as close to failure as you can, do as many repetitions as you get, because they don’t really go to failure anyway. In fact, there’s some of the meta-analyses on this we see that many people, the average gym goers, literally leave like 6 or 7 reps in reserve doing most of their sets. These people should not be confused with repetitions in reserve, stimulus to fatigue ratio or any of that. They should simply be told to do as many repetitions as you can. And even for well-trained, serious lifters, this is the most time efficient and best advice also for tracking.

Even if you are very serious lifter repetitions in reserve are always highly fallible. Most people are off by at least one repetition, and some people are off by a lot of repetitions. So if you leave any repetitions in reserve, that increases the error gap and it makes tracking a lot less reliable. If you always do as many repetitions as you can, it makes tracking the most reliable, which facilitates progressive overload and the ability to tell you if your program is actually working. The one scenario where repetitions in reserve still is actually very useful is for power lifters because, as we noted earlier, the stimulus to fatigue ratio is a bit better when you’re not going completely to failure. So leaving, say, 2 to 3 repetitions in reserve does seem to allow you to accumulate more high quality volume.

If your goal is primarily strength as a powerlifter, then it might make sense to train with some repetitions in reserve, especially if you’re doing a super high volume training program. However, for people training primarily for physique reasons or even recreational trainees that just want general strength development, this really shouldn’t matter much. And as I said, the research probably underestimates the effect of training to failure on strength development because the studies are very short term and in the long term muscle growth has a much stronger effect on strength than the neural adaptations we see in short term studies.

I hope this knowledge helps you make better training programs and get better gains. If you want a free training program using my methods, you can check out the MS Physique app with a two week free trial in the link below. If you want to learn everything there is about how you should construct optimized training programs based on the latest science and practical experience of coaches, check out my online PT course. If you just want more free content, I’d be honored if you like and subscribe. See you next time.