“The height of cleverness is being able to conceal it.” – Francois de La Rochefoucauld

Ever wonder what the relationship is, in a practical sense, between systemic fatigue, workout-induced muscular failure, workout volume, and that oftentimes misinterpreted word, “intensity”?  And, more to the point, what is the interplay between these factors and workout frequency?  And what about the impact of these factors upon performance (whether athletic or body composition)?  And for that matter, overall health?

Well, before we even begin let’s agree to approach this question from a real world perspective.  In other words, let’s simply consider how one looks, feels, and/or performs.  Somewhat subjective, yes (the look and feel part, at least).  But the reality is that unless you are a monitored, high level athlete, or under some pretty intense medical scrutiny, looking, feeling and performing will be the only parameters you’ll realistically have access to…or even really care about.

Let’s first consider the term “intensity”.  And right out of the box, we need to understand that there are two definitions of this term in the S&C world — one of them academic, and the other more generally understood.  The academic definition of the term describes a percentage of one’s 1 RM in a particular lift; the higher the percentage, the higher the intensity.  The more generally understood term relates to level of focus, desire, drive — or my go-to (and Five Ts) word, tenacity.

So while a few sets of high intensity (high percentage of 1 RM) squats will certainly require a high level of intensity (in the generally understood sense), does that then imply that 10 sets of 10 at a low intensity weight is not extremely intense?  

Of course not.  The 10 x 10 just doesn’t produce the same degree or manner of physiological “hit” to the system.  Now, I don’t claim to know exactly what constitutes this so-called “physiological hit” — other than it’s more muscular in nature vs the more CNS centered hit delivered by busting through some high percentage lifts — but I do know that it’s (the more “muscular” hit) much easier to recover from.  And hence I could, if I wanted to, workout a different body part (or movement pattern) the following day.  Systemic recovery from such a workout (no matter how “intense”) can be that quick.  Welcome to the origins of the traditional bodybuilding splits.

So the muscular fatigue produced via a more traditional lower-intensity/higher volume bodybuilding workout does not elicit the same, devastating systemic fatigue that a more comprehensive, higher-intensity throwdown produces.  The sliding-scale, systemic fatigue producing nature of these two types of workouts then dictates the frequency at which these two types of workouts may be undertaken.  It also dictates the proper mix-and-match between an athlete’s “in-the-gym” and “on-the-field” work.

My own per-workout construction and overall workout frequency is an outcropping of this concept.  How is it that I’m able to workout 5 or 6 days a week?  Systemic fatigue and overall stress management via intensity (in the academic sense) manipulation is the answer.  Two CNS-draining barnburners a week plus 3 or 4 “bodybuilding” workouts a week and I’m looking, feeling and performing good.  I also realize that all stress — whether physical, mental, you name it — adds to the overall stress account.  Going through a hellish week at work is not the time for a brutalizing string of workouts.  Pick the right tool (modality), and a mix of lesser intensity and volume, keep the table set, and live to fight another week.

Now, I love working out.  And I prefer the more high-intensity, CNS-depleting efforts to traditional bodybuilding — that’s just how I’m wired.  But too many of those barnburners in a week and I’m hammered for sure.  So what if I want to throwdown in this manner 3 or even 4 times in a week?  Simple — I have to say goodby to my more bodybuilding-oriented workouts that week.  And I’ll have to be even more coo-coo-ca-choo than I normally am.  Sometimes I’ll purposely over-reach so as to push the work capacity/stress tolerance envelope (a topic for another post), but since I’m not currently training for competition, I don’t see the need for that now.

Also note that I don’t need to make room in my program for sport-specific technique development.  This is a huge issue to have to consider when putting together an overall program for an athlete.  I’ve written on this interplay before (here and here). 

So while I wouldn’t normally recommend say, a single-set-to-failure protocol for optimum hypertrophy development, I’d for sure (depending upon the circumstance) recommend it for certain other applications.  Context matters, for sure.  So does choosing the best tool for the job.

Which brings us to the topic of work capacity, or the ability to both sustain a high degree of effort within an individual workout, and recovery quickly (and fully) from repeated, high-effort workouts.  And like any other quality, this can be improved via smart programming.

When I was younger and had all the time in the world, I trained most every day and with brutalizing throwdowns that, on paper at least, looked like a direct highway to adrenal meltdown.  This was on top of (during the summers, at least), working a demanding concrete construction job.  I can’t even imagine what the critique of the internet overtraining police would have been.  Anyway, so did I wind-up careening over the meltdown cliff?  Leave my adrenals in a smoldering heap?  Hardly.  

What actually happened was that my work capacity skyrocketed, and I got progressively bigger, faster and stronger.  Of course I had zero stress at the time.  And was in my hormonal prime, so to speak.  But still…

Now this is going to sound very hackneyed, but I came of age and was coached by those who lived and operated by the creed that “there is no overtraining, only under recovery”.

Maybe not as explicit as CT, but you get the idea 😉

Now, I’m aware that this may sound very bro-science to the enlightened, but there’s actually plenty of wisdom here.  Because the same coaches who taught me to go balls-out in every, 6-day-per-week workout, also programmed accordingly (via the academic sense of the word intensity), and hammered home the fine art of proper refueling, sleep and stress and fatigue management.

But here’s the thing: just because you can bring up your work capacity to the point where training 6 days a week is a reality, does that imply that you should train 6 days per week?  I mean I was competing at this point in my life, and health was just a vague concept that I figured I’d always have.

Well, boosting work capacity totally depends upon your goals.  If you’re looking to be a high level, competitive athlete, days off are going to be few and far between.  Get over it — that’s just part of the Faustian bargain.  Great health, on the other hand, can be accomplished in as little as 1 hour of smartly-programmed training (plus some daily movement) a week.  You’ll have to find your “home” somewhere within that wide spectrum, depending upon what you want out of the S&C game.  And depending upon how much time you’re willing to invest in the process.  Diminished returns is the name of the game here.  Of course I don’t have any verified numbers to offer you, but I’d say a pretty solid, in-the-park swag is to say that you could reach, with smart programming, maybe 80% of your genetic hypertrophy potential in as little as an hour per week. Want to bump it to 90%?  Better invest another 3 hours per week.  Trying to top out?  Better be willing to throw another 7 hours on top of that.  And be damn sure your nutrition, sleep, recovery and stress management is flawless.  You get the idea.  And this is just the hypertrophy side of things.  Sport-specific technique is another issue entirely, though the diminished returns idea is applicable here as well.  

One other variable we also need to consider is muscular failure.  And more to the point (and from a performance standpoint), does momentary muscular failure in any way correlate to the optimum amount of stimulus within a muscle for a given workout session?  Yet another way to frame this is to ask if single-set-to-failure is an optimum training regimen. Well, in my experience, though the premise of training the target muscle to it’s breaking point (and no more), then backing off and recovering seems logical enough, it simply isn’t the entire answer.  But then again, no single program is.  Hypertrophy is a multi-faceted phenomenon, as is athletic betterment.  Again, I’m considering this question purely through a performance lens.  Health is another matter entirely.  As is the aforementioned idea of diminished returns.

That being said, I don’t believe that per-set, momentary muscular failure constitutes the final word on optimum muscle “inroading”; i.e., that amount of work that will produce optimum results.  I think it is but one factor in a multitude of modality-specific indicators that must be considered.  And here is where art and experience comes into play.  How much is enough?  I can’t say exactly, but I know it when I see it in those I train, or feel it in myself.  I realize this is not an acceptable answer to the more literal/science-minded, but until we do have a definitive answer (and we can correlate it in an n=1 sense), it is simply the nature of the beast.  And this in no way implies that we should give up searching for the answer, either.  

But back to muscular failure.  Simply put, “failure” has just as much of a  psychological element to it as a physiological one.  So this is where experience comes into play — experience in manipulating intensity and volume in such a way as to maximize the desired outcome.  Because the truth of the matter is that the mix is going to be entirely different depending upon what goal we’re chasing (hypertrophy, strength, athletic performance, etc.).  It’s also going to shift person-to-person.

Be comfortable with this mix of art and science.  Become comfortable, too, with balancing fatigue, stress, intensity and volume.  Learn to be a true chef vs reheating someone else’s leftovers.  Or worse yet, relying on prepackaged, frozen dinners.

In health, fitness and ancestral wellness –


  1. Great post, Keith.

    From my experience, and in some of the newer research publications, the distinction between higher and lower volume (that old-fashioned ‘volume vs intensity’ is a myth no longer of validity) misses out on the fuller spectrum. For example, you just don’t see mention of hypoxia associated with Kaatsu or occlusion type training, a method known to pile on hypertrophy.

    As we discussed a few weeks ago, at this stage of life I’m reticent to do 1RM or even 6RM work for ensuring training longevity. With that I’ve done much experimenting with higher reps, both straight away and through zones, static holds, x-reps – anything inflicting Time Under Tension, pump, burn and that stretched feeling arising from occlusion. Pump and occlusion are subjectively different, and metabolically different.

    I find such type of training results in faster recuperation and unexpected hypertrophy. Nice prizes! Perhaps due to more emphasis on sarcoplasmic hypertrophy metabolic processes than the actin-myosin associated with contractile strength training.

    Another blessing is when I do get to relatively ‘heavy/low rep’ sets, the degree of fatigue keeps resistance lighter, tendons happier.

    That said, us elders may be less performance oriented than younger generations. As Bill Pearl put it, there’s a point where gains no longer matter because maintaining is the name of the game.

    • Right on. Pump and/or occlusion are two more subjective variables to consider. Lots of bang for relatively little recuperative cost.

  2. 80% of maximum potential, in 1 hour per week seems like a pretty damn good Return on Time Invested.

    So if you are primarily into training to improve health, and want to look good as a side benefit (e.g., 80% of your hypertrophic potential), what is that hour of training going to look like, for the average/typical Joe?

      • Keith,

        I’d like to see the response to Craig’s question as well. I suspect that it would speak directly to my interests, and to the approach I’ve taken (something to check myself against as it were).

  3. That should be interesting. I’d be especially interested in a “train less as you train more intensely over time” vs “improve your work capacity” debate. You know, HIT coaches regard recovery as linear, while it’s certainly not, and we probably can’t determine if one is recovered based on variables like subjective fatique or progress in numbers, but even those are questionable. in their relation to what actually happens to your body. Is it better to workout constantly twice a week for 30 minutes even though the progress slows (in numbers)/you fel slightly tired, or is it better to spread it out if one is a fan of those 80% for 1 hour? At the moment I believe the two sessions a week are just too valuable to drop both mentally and physically (and for CV fitness as well), but that might change as I progress.

    I am also a fan of simplicity, so I’d like to discuss if one full body workout of about 8-12 erxercises (enhanced big 5) yert still short enough to be intense and get under 30 minutes could be efffective long term with NO changes, twice a week. I guess that except of boredom, it should be. Although an A/B routine with more exercises could be better, maybe. But the fact you learn one workout in excellent manner and just focus on muscles and improve the poundages also has merit.

  4. Keith,

    I want to thank you (and Ken for his excellent commentary) for informing some of my training decisions the last couple of years. For a while I entirely “emptied my cup” and went full bore HIT Jedi and your blogposts in part convinced me to experiment with higher volume and higher frequency.

    I’ve come to the same conclusion as you that 80% of potential can likely be reached with only 20% of the effort (1-2 HIT sessions per week). But if you want to push the boundaries of what is possible, you NEED those other 20, which necessitates the less efficient time investment.

    I’m actually heading into my first Physique competition next weekend, so for the last month and a half or so I’ve been doing a more HIT oriented routine aimed just at retaining muscle in a calorie deficit without overdoing it on volume. But after next week I’m looking forward to continuing to tinker with this whole volume/frequency thing! Keep the thought provoking posts coming!


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.