Thoughts On Counting Training Volume – By Greg Nuckols

Greg NuckolsTraining12 Comments

Can We Predict Muscle Growth?

 

This article was originally published on Strengtheory.com under the title Can We Predict Muscle Growth? We thought is was an excellent discussion piece and asked Greg, one of the brightest young minds in the industry, to share. Enter Greg Nuckols…

It’s well-understood that higher training volume generally means more hypertrophy. However, defining and measuring training volume isn’t quite as straightforward as we’d like it to be. There are several different ways to measure training volume, including volume load, relative volume, “effective reps,” time under tension, and number of hard sets. All of them have their strengths, but they also have drawbacks.

The question isn’t, “are higher training volumes generally better for hypertrophy?” The question is, “are any of the ways we can measure training volume actually causative, or at least strongly predictive of hypertrophy?”

Volume Load

The most popular way of measuring training volume is probably the trusty old volume load: sets x reps x weight.

There are a few major problems with volume load, however.

1) Using volume load will lead you to the assumption that exercises you can load heavier will inherently be better than ones that don’t allow for as heavy of loading.

For example, you could do an equally hard 3 sets of 8 reps with front squat or leg press, and the leg press will likely leave you with twice the volume load (or more). I’d be very surprised if quad growth was meaningfully different, though. Or, you could do 5 sets of 10 bench press vs. DB press; volume will be way higher for bench press, but pec growth would probably be about the same. Additionally, shortening your range of motion allows you to rack up a higher volume load, but shorter ranges of motion are generally less effective for hypertrophy.

In other words, volume load only tells you something meaningful when comparing an exercise to itself; if you change exercises, then volume load is effectively meaningless.

2) Even within the hypertrophy range, volume load varies dramatically.

For example, let’s say you wanted to compare 4 equally challenging sets of 6, 8, 10, 12, and 15 reps, and your max for the lift in question in 200lbs. You’re going to leave a couple of reps in the tank on the first set to make sure you can get all 4 sets in. So, you’ll probably be using about 78%, 75%, 70%, 65%, and 60% of your 1rm (from Brzycki’s table, extrapolating a bit for the sets of 15).

4 x 6 x (200 x 0.78) = 3744lbs

4 x 8 x (200 x 0.75) = 4800lbs

4 x 10 x (200 x 0.70) = 5600lbs

4 x 12 x (200 x 0.65) = 6240lbs

4 x 15 x (200 x 0.60) = 7200lbs

Can We Predict Muscle Growth

As you can see, even within the “hypertrophy range,” volume loads vary wildly. Using volume load, you’d assume that sets of 15 were dramatically better than sets of 6. Heck, even if you’re a purist who defines the hypertrophy range to be 8-12 reps, you’re still looking at 30% higher volume loads for sets of 12 versus sets of 8.

In other words, volume load only tells you something meaningful when working at the exact same percentage of your 1rm. Even small changes in loading (5-10% of your 1rm) will dramatically change volume load, even within the “hypertrophy range,” making comparisons much less useful.

3) The relationship between volume and hypertrophy, even when equating for all other factors, is far from linear.

In James Kreiger’s 2010 meta-analysis looking at the relationship between number of sets performed and hypertrophy, the effect size for a single set was .24, the effect size for 2-3 sets was .34, and the effect size for 4-6 sets was .44.

So, even if you’re holding everything else equal, then you could do 2-3x as much work for about 40% more hypertrophy, going from 1 set to 2-3 sets. Then, you could double the amount of work you were doing again to 4-6 sets, and expect to grow another ~30%. Comparing 4-6 sets to a single set, you’d be doing 4-6x as much work for about 80-85% more growth.

So, if you did 4×8 with a given percentage of your 1rm last week, and you increase that to 5×8 this week, your volume will increase by 25%, but it would be foolhardy to assume you’ll progress 25% faster. 5-10% faster is a more realistic expectation. Is it better to do 5 sets than 4 sets? Probably. And volume load reflects that. However, it says nothing about how much of a change to expect.*

This works in reverse as well. For example, if you were doing 3 sets of 15, and you switch to doing 6 sets of 6, it would probably be realistic to expect your rate of growth to increase. However, your volume load would be essentially unchanged: 5400lbs before and 5616lbs after, assuming the same 200lb max; that’s only a 4% difference in volume load.

In other words, increases or decreases in volume load don’t tell you how much you should expect rate of hypertrophy to increase or decrease.

*Aside: I’ll also note that this will be true for essentially any system you use to track your training, since muscle growth’s relationship to effort (however you quantify it) is logarithmic or parabolic rather than linear. However, it’s been my experience that people tend to overestimate the predictive power of volume load moreso than other systems, simply because you do a fair amount of calculations and wind up with a nice, pretty number at the end of it. It feels so scientific and predictive. I’ll also note that I still think volume load is useful for work capacity blocks because the metabolic cost of exercise increases roughly linearly as you do more work. If the volume load you can handle in a given time period increases (assuming you’re using the same exercises or similar exercises), then your metabolic capacity for training and work capacity have likely increased as well.

Relative Volume

One way to improve upon volume load is to use relative volume. Instead of sets x reps x weight, relative volume is sets x reps x %1rm. This lets you directly compare different exercises; you’d count a set with 75% of your max front squat the same way you’d count 75% of your max back squat or 75% of your max leg press, all of which would probably have a similar effect on muscle growth. However, relative volume still has the other two problems associated with volume load: small changes in loading having large effect on relative volume, and moderate changes in relative volume having pretty small overall effects on hypertrophy.

So what are some other ideas are out there?

Effective Reps

One that has a lot of intuitive appeal is the notion of, “effective reps.”

In a nutshell, the idea is that the “effectiveness” of each rep for muscle growth increases as a set progresses, and that the last few reps are the real “money reps.” So, if you were doing a set of 10 with a 10rm load, it doesn’t really take that much effort to do the first 5 reps, and they probably don’t cause much of a growth response. The 6th and 7th reps may be borderline effective. The 8th, 9th, and 10th reps, on the other hand, are ones that really net you the majority of your growth.

If we assume that muscular tension is primarily effective for hypertrophy because tension and motor unit recruitment tend to go hand-in-hand, it is true that muscle activation increases as you get closer to failure. Additionally, as you get closer to failure, metabolic stress increases (all other things being equal).

However, the evidence supporting “effective reps” is also shaky.

For starters, I’m not sure I’ve ever seen an objective definition for an “effective rep.” Is it the last 2-3 reps per set, regardless of conditions? Is there a certain motor unit recruitment threshold you have to cross? (More importantly, how would you know you’d crossed it? That’s another discussion for another day, though.) Is it related to how much fatigue you accumulate per set?

If it were the last few reps per set regardless of conditions, then you’d expect training to failure to be substantially more effective for muscle growth than training that stops before failure. However, a recent meta-analysis found that there aren’t any meaningful differences in muscle growth between training to failure and training that stops before failure, and that, in fact, training that stops a bit shy of failure may actually be a little better.

If it were based on crossing a motor unit recruitment threshold, then we’re still several years away from even being able to test that idea. Measuring muscle activation is a lot more complicated than people think.

If it were based on fatigue accumulation per set, you’d expect super light training to be way better than heavier training. If you were training with 50% of your 1rm and failed at rep 30, then you were only half as strong at the end of the set than you were at the start of the set. However, if you were training at 75% of your 1rm and failed at rep 10, then you were still 3/4 as strong as the end of the set as you were at the start of the set. You accumulated twice as much fatigue training with 50% of your 1rm. Does that mean you’d grow dramatically more? Probably not.

Finally, an implication of the “effective reps” idea would be that advanced techniques like drop sets and rest-paused sets would be dramatically better for muscle growth. Thus far, the evidence does not support that notion.

As intuitively appealing as “effective reps” are, there’s no way to objectively measure them and there’s quite a bit of evidence that refutes their explanatory power. It’s a neat idea that’s not very useful.

Time Under Tension

Moving on, another idea that is still pretty popular is time under tension: how long it takes to complete all of the reps in a workout. Some people measure time under tension for the entire reps (both the eccentric and concentric portion), while other people only measure concentric time under tension.

However, time under tension as a predictor of hypertrophy doesn’t have much support. For starters, a recent meta-analysis showed that rep cadence doesn’t have a meaningful effect on muscle growth (prolonging a rep would increase time under tension; therefore you’d predict that slower reps would lead to more growth), and that, in fact, very slow reps – those lasting longer than 10 seconds – actually lead to less muscle growth than faster reps.

Furthermore, multiple studies (that will be discussed in the next article) have shown that training protocols with vastly different times under tension lead to similar hypertrophy. Of all the options given thus far, time under tension is probably the worst predictor of muscle growth.

One slight twist on the idea of time under tension is the idea of “time under maximal tension,” first popularized by Fred Hatfield. However, as far as I can tell, this runs into the same issues as “effective reps”; it’s nigh impossible to pin down a way to objectively measure it, and it’s also more about strength development than hypertrophy in the first place.

Mike Tuchscherer discusses the idea of time under maximal tension in this video:

Counting Hard Sets

Lastly, there’s the way I personally like to measure training volume: number of hard sets, or sets within a couple reps of failure.

Simply counting the number of hard sets circumvents the first two problems with volume load, and one of the remaining problems with relative volume: A hard set of leg press or bench press is counted the same as a hard set of front squats or DB press, and a hard set of 6 or 8 is counted the same as a hard set of 12 or 15. Finding the training parameters that allow you to handle the highest number of hard sets per week (which entails finding the rep range you can train the hardest and recover the best from between sessions and between workouts) will probably be more useful to you than finding the training parameters that allow you to handle the highest volume load (hint: exercises you can load heavy, with high reps per set, staying a pretty long way from failure to make recovering between sets easy).

However, counting hard sets has some drawbacks as well.

For starters, there’s no way to account for sets that aren’t very hard, even though they can also cause muscle growth. Previous research has shown that sets taken to failure cause about the same amount of growth as sets taken about two reps from failure, but how do you quantify sets that are even easier than that?

Furthermore, this has one of the same drawbacks as volume load: Muscle growth does increase as you do more hard sets, but the increase isn’t proportional to how many hard sets you do. Again, you’ll do a lot more work for modest additional benefits. Anecdotally, however, I do find that people don’t get as hung up on the precise numbers when counting hard sets versus tallying up volume load.

Finally, research shows that not all hard sets are created equal. For example, resting longer between sets generally causes more muscle growth. However, a set of 8 following a minute of rest may be just as hard as a set of 10 following 3 minutes of rest. This is actually a time when volume load and relative volume have an edge over number of hard sets; the drop in workload from cutting rest periods is reflected by volume load calculations, but not by counting the number of hard sets you do.

Differing ranges of motion also affect growth, but aren’t reflected by either volume load or number of hard sets. A set with a longer range of motion will generally cause more growth than a set of the same exercise with a shorter range of motion, but counting hard sets would predict the same growth. Volume load would actually predict that shorter ranges of motion were better since you could use a heavier weight for the same amount of reps.

One final consideration I want to drop into the mix: not being lazy and just putting more effort into your training is a really good way to get better results. However, it’s hard to quantify effort you put into training a muscle group; it’s important, but also impossible to track.

At this point you may be saying, “Holy crap, dude. You’re basically saying that there’s no good way to predict how much I’ll grow from my training?”

To which I’d respond: Yep, pretty much.

Of the available tools, I personally think tracking the number of hard sets per muscle is the most useful, followed closely by relative volume, but all of them are pretty rough and have pretty big drawbacks. This is to be expected. What’s going on outside your body doesn’t necessarily tell you all that much about what’s actually going on inside your muscles. There’s no bean counter in your muscle fibers that tallies up your volume load, or switch that’s flipped when you reach a certain motor unit recruitment threshold or blood lactate concentration. Muscle growth seems to be one of the many things where the complexities and redundancies of your physiology make application much simpler.

Now, there may be some variable that does predict hypertrophy pretty well that we just don’t know about yet (or it may be something like impulse that you can only measure if you have some lab equipment at your disposal). However, at this point, the best way to sum it all up is this: Hard work makes muscles grow. More work and harder work generally make them grow more.


One final, slightly technical note:

I know some people will object to my conclusions here and point out instances where volume load was matched and the same amount of hypertrophy occurred, or when a group with more time under tension had more hypertrophy than some other group in some study.

However, in science, falsification matters more than confirmation. In other words, you could throw out these studies in support of the position that volume load is causative or strongly predictive of hypertrophy (one, two, three, four) because in all four of those studies, volume load/relative volume were the same, and hypertrophy was very, very similar between the groups being compared.

However, all of these studies falsify the idea that volume load is causative or strongly predictive of muscle growth (one, two, three, four, five, six, seven, eight, nine, ten, eleven). In all of these studies, either volume load was the same but hypertrophy was different, volume load was different but hypertrophy was the same, or volume load was different and the group with a lower volume load grew more than the group with a higher volume load.

In an applied science, a single falsification may be a fluke, but at this point, there’s more than enough evidence to say that volume load may be useful on some level, but that it would be a huge stretch to say it was causative or even strongly predictive of hypertrophy.

That’s why my takeaway for this article is worded broadly: Hard work makes muscle grow. More work and harder work generally makes them grow more. I think that’s about the safest statement about muscle growth, and also the most useful, since it helps keep people from getting hung up on details that are much less important.

12 Comments on “Thoughts On Counting Training Volume – By Greg Nuckols”

  1. What about volume when you’re in contest prep, what would be the optimal amount of volume? From the start till the end?

    The reason I ask is because I’m just over 2 weeks out and out of the blue my energy and focus levels have took a HUGE nose dive, I cant lift nearly as heavy and I’m really struggling to function in my day job.
    An increase in calories isn’t an option this close out and I’m scared to reduce my cardio incase is slows down fat loss as I’m not quite there yet.
    In the ideal world, I should have been ready earlier but this is my current situation so any help is greatly appreciated.

    1. Hi Gary, thanks for the comment. Your question and your issue aren’t really aligned here, which is good, because the answer to your first question is a vague one by necessity – as much as you need to keep progressing (at the start of the cut), and then eventually stop regressing (at the end of the cut). Generally, work volume will be tapered towards the end of the cut so that you can stay within the x-axis intercepts (under the positive response part of the curve).

      Now, your issue is probably just one of cumulative fatigue coming to bite you in the arse. Take a deload week. You won’t lose muscle mass, and there will be no meaningful effect on the weekly calorie expenditure from doing so so fat loss rate will not be affected.

  2. Hey guys,
    Im wondering why Greg did not talk about the volume recommendations of the Pyramid Training book (40-70 reps/muscle group/session x 2-3/week)?
    I understand the reasoning for his counting hard sets method but volume could vary wildly with this method. I could do 15 hard sets in the 1-5 range or I could do 15 sets in the 8-12 range for a muscle group. The mathematical difference is huge.
    Some clarification would be great.

    Thanks!

    1. Hey Freddy,

      I think this article (https://strengtheory.com/hypertrophy-range-fact-fiction/) will help further explain why I think normalizing based on number of sets is better than normalizing based on reps.

      If you’re training with 8-12 reps per set and around 70-80%, 40-70 reps may be a good general rule of thumb, but it may also be way too many reps if you’re training with a higher percentage of your max, and way too few if you’re training with a lower percentage of your max. Prescribing a specific number of reps implies prescribing a particular intensity zone as well, and I haven’t seen any evidence to convince me that one intensity zone is necessarily better than any others as long as all sets are taken to or near failure.

      I think 2-3x per week frequency is a solid recommendation, though.

      Greg

  3. Would you predict the same hypertrophy with
    Scenario 1: you do 6-7 hard sets using a 1-minute rest period and 20+ reps on the initial set and letting the reps drop from set to set because of fatigue.
    Scenario 2: you do 5 hard sets using a 2-minute rest period in the hypertrophy range.

    Would the additional 1-2 hard sets compensate the use of a shorter rest period and not working in the hypertrophy range?

  4. Thanks for the excellent article, Greg!

    I like your conclusion: “Hard work makes muscle grow. More work and harder work generally makes them grow more.”

    Here’s a thought:

    Instead of focusing on means, why not focus on ends?

    Let me expand:

    A testable hypothesis is that the degree of muscle mass a person carries is correlated with the amount of work their muscles can do, where ‘work’ is defined in the physics sense: the integrated force x distance over which the force is exerted. Thus, given a fixed ROM, the work will be related to total reps x load. A person who carries more muscle can do more work on average in the gym (total reps x load) than a person who carries less muscle (which makes intuitive sense).

    It does not matter how this total workload is achieved: low reps, high load or high reps, low load- a claim which seems to be supported by recent studies of Stu Phillips, Brad Schoenfeld and others.

    If a person is able to do more total work this week than last week, their muscle mass will increase.

    Do you see any problems with this hypothesis?

    1. Hey there, not Greg but happy to respond given this isn’t Greg’s site (original article is there if you want to engage with him).

      Not an unreasonable hypothesis, but 2 things to consider: 1) volume is not the only variable that is causal for hypertrophy, however it is a main one 2) a week is an arbitrary unit of time, it may very well be that the same load and volume will continue to stimulate hypertrophy…until it is insufficient to do so, thus it can very quickly become untenable trying to create progressive overload on a week to week basis after the beginner or intermediate stage. Volume increases and load increases should come in a gradual fashion, as needed, when measurable progress stalls. Much more detail in the books if interested.

      Regards

      1. Hi Eric,

        Thanks for the reply on behalf of Greg! Yes, I agree that there are several important qualifications to the hypothesis. A big one is diet: one can do more work (e.g., lift more weight for more reps) when one is not in a caloric deficit and glycogen depleted). Another factor to consider is leverage. I have long limbs, so I do more work when I press the same weight as someone with short limbs, since I must move it over a larger distance.

        But controlling for these and other variables, one might predict to observe a correlation between total volume-load (averaged, say, over the course of a month or two) and muscle mass, assuming these could be reliably quantified. All else being equal, it seems reasonable to expect someone who can do more overall work in the gym to be more muscular than someone who can do less work.

  5. Something I am considering after reading stuff from Greg and Brad is a volume/intensity progress hybrid. Please chime in and correct me if the logic is flawed.

    I will take and exercise and preform 50 total reps with it, after warm ups. So say I warm up, put 70% on bar, and do whatever reps come out on each set, always staying just shy of failure by 1-2 reps. Keeping count of each set till total of 50 reps is reached, as in perhaps.. 15,12, 9, 8, 6

    Now the weekly progression will be to add weight to the bar, lets say 5-10 lbs. Now your reps will drop from previous workout, all sets, as said stay 1-2 from failure, but now that 50 total takes maybe one more set to achieve. Next week add weight again, reps per set drop again, adding another set or two to reach 50 total. Third week add weight again, more sets to reach that 50 rep total. Forth week drop weight and reset..test.. etc

    So my “thinking” is that your never trying to “beat” anything., but you are forcing overload “comfortably” Your safe in the 1-2 reps from failure or tech. breakdown. You are forcing progression weekly, while total volume stays the same with number of lifts, the sets will fluctuate as the weight goes up, taking more to complete the total number of lifts. To me this seems reasonable, but your workout lengths will increase as the weeks go by. Week 4 I will drop back to the original start weight and should see a bigger increase in the number of reps before the 1-2 failure mark….considering implementing this soon.

    1. That’s a perfectly reasonable way to approach progression Eric T, just be aware volume in terms of repetitions is static, but relative volume load and total volume load is going up. I’d pay attention to overall recovery, and see how long you can push the same number of reps at heavier loads before joint stress and fatigue and DOMs become problematic, but definitely viable.

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