Time Under Load

“Colleges hate geniuses, just as convents hate saints.”

Ralph Waldo Emerson

Question; would you train this athlete…

That's my boy --

That's my boy, shorin' up the hot corner

…the same as this knucklehead?


Well, the fact is, that in many ways science tells us that they should train the same.  The rub comes from the fact that empirically speaking (and this is where the art of training comes into play), there are some subtle, yet very important ways in which they should never be on the same page.  Let’s consider just one aspect of training for a moment: time under load (or, if you prefer, time under tension).  We’re taking about muscular gains, here; gettin’ swole — hypertrophy.

From the Wow, that sounds a lot like Dr. McGuff files…

So I came across an interesting T-Nation article recently; interesting, not so much for the training protocol information it provided, but in that who the author was endorsing this particular protocol — namely, Dave Tate.  The subject of this particular article is hypertrophy, and how best to train for that end; the interesting thing is, once you break down the science behind what Dave Tate is endorsing here, it becomes clear that both he and Doug McGuff (and anyone seeking pure hypertrophy, for that matter) are preaching from the same pulpit.  The delivery methods are different, and the delivery men might as well be from different planets, but when broken-down to the bare essentials, the message is strikingly similar.  The total time under tension between the two protocols each endorses are, well, nearly identical.  Why?; because it’s been shown both scientifically, and (most importantly), empirically to work.

Now remember, we’re speaking strictly of hypertrophy gains here.  If you’re a seasoned athlete who’s primarily concerned with strength, power and speed gains, such a protocol is likely (at least during the protocol itself, and for the near future thereafter) to negatively affect those aspects.  This is why when I go on a hypertrophy bender (25 for a bigger engine), I prefer to shade a little more toward the strength end of the spectrum.  Sometimes, though, an athlete has to take a step back in order to take two forward.  Just a little something to keep in mind.  For those new to the iron game, though, it’s a different story.  But hell, newbies can perform repeated sets of — hell, I dunno — carrying  dumbbells from one end of the gym to the other, and make gains in both strength and size.  As always, keep in mind the cardinal dictate: Know thyself, know thy weakness(es) and know thy goals.

Back, though, to time under tension.  In the article, Dave Tate points out (correctly, in my experience), that the best hypertrophy gains are made — regardless of the specifics of the protocol, so long as the muscle(s) in question is/are placed under a constant tension with a load sufficient to induce temporary failure within a time period of 30 – 45 seconds, with a total time under tension not to exceed 90 to 135 seconds.  Again, we’re speaking about an emphasis on hypertrophy here.  Why these time brackets?  Because we want to hit that sweet-spot balance between exhausting all fibers (time and load dependent), and not allowing the slow twitch fibers enough time to sufficiently recover.  Now, there’s lots of room to maneuver within these two requisite time brackets — sets, reps, tempo, method — but just remember with the goal being hypertrophy, we want to aim for exhaustion of all muscle fiber types affected by the applicable exercise.

Something I’d like to quickly point out before we move on: a physiological response to induced stress (in our case, the body’s response to an exercise bout), cannot be isolated, nor can it be segmented.  That is to say, it is impossible to classify one modality as purely hypertrophy-inducing, strength-inducing, or otherwise.  And to convolute matters a bit more, we’ve got the variances in each individual’s genetic “hand” to deal with.  Personally, I rarely lift with a hypertrophy response as my aim, and yet I’m fairly well hypertrophied.  And conversely, I’ve run across athletes who rarely perform other than hypertrophy-leaning protocols, and who yet maintain an explosive, power-producing ability.  The latter case is much more rare in my experience, and yet I have run across it.  My point is that it is very important to think of exercise in the same way as, say,  insulin response to food ingestion, or the body’s energy system contribution in the face of various energy requirements.  We’re speaking in terms of shades here, not clearly defined cubby-holes.  There are no absolutes, only leanings.

Anyway, what’s interesting, when considering “Tate” protocol as compared to Dr. McGuff’s, is that we see the same, overall, time under tension prescription.  Tate breaks his up between three sets of 30 -45 seconds in length, per exercise, and he’ll perform 6 exercises in a workout.  That’s between 90 and 135 seconds of TUT per exercise, and, at 6 exercises per workout, we’re at a grand total of between 9 and 13.5 minutes of overall TUT in a single outing.  Looks rather familiar, huh?   What is different, though, is the prescribed dose.  Tate will perform his routine 4 times per week, whereas McGuff (in most instances) prescibes once/week.  Both methods, though, can be easily fine tuned by tracking the progress of one’s does-response.  Tate’s protocol splits the workouts so as to work roughly half the body in each workout, whereas McGuff takes an all-in-one view.  Stress is stress, though, as far as the body is concerned; that stress may be concentrated in one zone, but the overall response will still be additive on a whole body scale.  Keep that in mind.  What would be very interesting would be to put Tate on a McGuff protocol for a while and chart his dose-response curve.  I’d bet the farm that Tate would be a recovery “freak” and be able not only to tolerate, but make his best gains under 2 McGuff sessions per week.

By the way, I guess it’s TMuscle now, instead of T-Nation.  My bad; old habits die hard.  Different name, same chock- full-of-great-information site, though, that I love to hate.

Have a great weekend!

In health,


22 responses to “Time Under Load

  1. Keith, I’m starting to see some pattern here regarding time under load and keeping the exercise for a given body part to the 90-ish second range.
    – As Dr. McGuff points out in his book seems to be the most boiled down explanation of this point
    – Huge in a Hurry seems like it is geared toward the same thing, but comes about it from the opposite end of the spectrum via lighter weights and more reps
    – Evolutionary fitness via 15/8/4 recommends the first 15 slow, but no break and then immediately upping the weight for the 8 and 4
    – Superhumanradio episode 306 discussed how shortening of the rest intervals between sets tends to promote hypertrophy while longer rests seem to promote strength
    – the 5×5 (stronglifts) protocol also advocates to take longer rests between sets for increased strength

    Now, as you correctly point out there are many shades of gray between individuals and their response to different protocols. Personally, I’ve seen some benefits and plateaus from all of them. Like most people, I’m trying to find that stimulus that MY body responds best to.

    Tangential to that is a question for you. How much variation to stimulus exists for a given protocol within a given person? For example, I’ve been consistently seeing gains in exercises like squats and leg press (for various protocols), while other body parts seem to quickly hit plateaus (for the same protocols) and little to no gains. Assuming my applied intensity is the same and mechanics are not completely incorrect, this perplexes me.

    • A few things that come immediately to mind, Andy: (1) fiber-type concentration (can) vary wildly between body parts of the same person — and remember it is the fast-twitch type that shows the greater propensity toward hypertrophy, (2) Frame leverages, i.e., the body’s natural propensity toward finding the most efficient way to move a load. Think of the difference between a “triceps” bencher and a “pec” bencher, and which muscle group is called upon to carry the brunt of the load. Failure occurs when the weak-link fails. (3) one’s ability to efficiently recruit what fast twitch are available; that is to say, my in-road time (McGuff’s term, and I like it) may be only 5 secs for a particular exercise, but at an extremely heavy weight — a few rounds of that, and I’ve toasted everything I’ve got. You, on the other hand, may require a much longer in-road period; what fast-twitch reserves you have may be “reluctant” to get into the mix — at least, immediately. This, of course, will alter to some degree what TUT will best suit your needs.

  2. Hey Keith,

    Great stuff, thanks. I wonder if you could elaborate on this part of the post:

    “Stress is stress, though, as far as the body is concerned; that stress may be concentrated in one zone, but the overall response will still be additive on a whole body scale. Keep that in mind.”

    Does this mean that if I have the capacity within one week to optimally recover from a dose of, say, 100 units of work, that it simply doesn’t matter how I spread them out? BBS seems to say this: do 100 units one day per week, or 50 units twice per week (by splitting the workout), and allow time for proper recovery. But my (stubborn?) intuition suggests that I should be able to “cheat” the 100-unit dose/recovery limit if I just spread it out a little. So if I do 3 workouts per week, maybe I can get in 40 units each time for a total of 120; since I “only” did 40 units each time, can I somehow make my recovery more efficient?

    It’s sort of a theoretical question, but maybe you have some direct experience that would shed some light on it. My nagging thought about the BBS protocol (which I am currently trying) is that I “should” (and could) be doing more work. (I’m still doing a couple of sprint-interval sessions per week, but no other weight training besides BBS.)


    • I think in some sense this is true, yes; however, remember that we accumulate stress on a daily/weekly basis with things totally unrelated to physical culture — work, family, proper diet (or lack thereof), you name it. That is to say that Monday you may be flying high, get your “50 units of workout” in and be primed for Thursday, only to be slammed at work and with an impending foreclosure on Tuesday and Wednesday — will 50 units of work now be possible on Thursday? And if it is, physically, will it be beneficial to your health goals? This is one reason why I’m a big proponent of mapping “progress” (however you choose to define it, related to your goals) on a macro scale, and measuring drop-off on a per-exercise scale, and then relating/comparing/contrasting the two. So in the above example, on Thursday I’ll likely hit drop-off quickly (or with lighter load, or fewer sets, reps, or a decreased TUL). This will prevent me from overtraining on both a micro, and, if I’ve tracked/logged diligently, macro scale as well.

  3. Keith,

    Excellent and thought provoking post. One difference between the two methods that I can see is that Tate is using a heavier weight relative to his 1RM to get to failure in 30-45 seconds whereas Dr. McGuff is using a lighter weight relative to 1 RM in order to extend the set that long. According to the accepted definition of inroad the McGuff set would reach a deeper inroad. Perhaps with the deeper inroad the body accumulates more fatigue by-products and is driven deeper into catabolism which would explain the 1x per week prescription.

    On the BBS site John Little described a workout they are experimenting with called a “done in one” in which you do one extremely slow positive (30-45 seconds) along with an extremely slow (30-45) negative. I tried it and felt like I had been beaten with a stick. I was way below baseline for several days. I figured out the amount of inroad and it was much more than normal. There is no way I could do that 2x per week. Tate is probably using somewhere from 80 to 90% of his 1 RM to
    get that TUL so it’s from 10-20% inroad and he’s resting enough to do it for 3 sets. In a way it’s similar to dc-training, you lift heavy but use some rest to cheat the fatigue.

    Consider this: What if a large part of the variability we see in trainees is more on response side of the equation? Almost everyone focuses on the stimulus. What if our genotoypes are all over the map in regard to how we tolerate exercise and if we could adjust our frequency and volume to fit our genetics we might not have to search so hard for the ideal stimulus.



    • I think that the stress toleration side of the equation (both actual and perceived, acute and chronic) accounts for at least 50% of the overall training outcome. That is to say, one could have favorable genetics in every other way, yet be limited to mediocrity due to poor stress toleration ability. On the flip side, great stress toleration can do much to level-up a lacking genetic hand.

      “Excellent and thought provoking post. One difference between the two methods that I can see is that Tate is using a heavier weight relative to his 1RM to get to failure in 30-45 seconds whereas Dr. McGuff is using a lighter weight relative to 1 RM in order to extend the set that long. According to the accepted definition of inroad the McGuff set would reach a deeper inroad. Perhaps with the deeper inroad the body accumulates more fatigue by-products and is driven deeper into catabolism which would explain the 1x per week prescription.”
      Quite possible indeed. However, I believe Tate’s ability to call quickly recruit and subsequently “toast” his available FT fibers is much more efficient (for the ends we speak of here) than is McGuff’s. I’d love to see Tate submit to a controlled study of both protocols; complete blood work, controlled diet, “subjective” measurements, outside stress control, you name it. I’m also curious how the BBS protocol would affect his 1RM numbers.

    • “Consider this: What if a large part of the variability we see in trainees is more on response side of the equation? Almost everyone focuses on the stimulus. What if our genotoypes are all over the map in regard to how we tolerate exercise and if we could adjust our frequency and volume to fit our genetics we might not have to search so hard for the ideal stimulus.”

      Also, see my reply to Mark L, re: drop-off.

  4. Stress side is hugely important, as both the principles of SAID and GAS have indicated over the years. the former for how you train, the latter for how frequently you change how you train.

    Also, it’s very interesting to see the difference of gene expression from one generation to another. Just seeing how your son’s limb length/structural size/proportions are so different than your own. My father and I share a similar differentiation…thank mother for that.


    • This is interesting. Up until the age of about 14, I expressed the same phenotype as what my son (age adjusted,of course) currently does; the tall, tight, “raw boned” look. Then I fell-in with the iron, train-for-football crowd, and I quickly muscled-up. My son has never trained heavily with weights — he’s never had any real desire to do so. I’d love to know how similar our genetic profiles really are, and how much weight training (and lack thereof) have affected the end phenotypes. Of note as well, he is in the 6’2″-ish range (at 18 y.o.), where I clock in at 6′-even.

  5. To All,

    Great article from Keith and great followup discussion. The basis for my determination of TUL is sequential recruitment of motor units. The weight has to be heavy enough to recruit and fatigue the slow and intermediate fibers quickly enough so that the fastest twitch fibers can be recruited and fatigued before the slowest twitch fibers have had a chance to recover and recycle their contribution to the effort.

    The optimal TUL is also related to the rep cadence that one is using. At a slower rep cadence, the TUL tends to extend. This has to do with the rate of work performance (both mechanically and metabolically), but is not completely understood (and is hotly debated). A weight that produces a TUL of 45 seconds at a 2/2 cadence will produce a TUL of 90 seconds at a 10/10 cadence.

    If you choose a weight that is much heavier there will be parallel recruitment of all fiber types and TUL will be determined by the fatigue rate of the fast twitch fibers. Because the movement depends on simultaneous recruitment of all fiber types, the set will terminate when the fastest fatiguing fibers fall out of the equation. This focuses on the fastest twitch, most productive motor units, but theoretically misses the opportunity to produce a glycolytic shift in the intermediate fibers, and misses some of the metabolic component that can be acquired with sequential recruitment.

    Individuals may start to experience a “signature TUL” that is a marker of their fiber type mix in a particular muscle group. This is recognized when you start to experience fatigue within a tight time-frame even with fairly large weight ranges. For instance, failure occurs at 75 seconds for several workouts in a row. If the subject later lightens the weight by 25%, or increases the weight by 25% the TUL stays around 75 seconds. This is a marker for a “sweet spot” where the subject can demonstrate his best effort and intensity and signals an opportunity to progress weight aggressively from one workout to the next.

    Having gone through all this, I must admit it is a bunch of hair-splitting hoo-ha. Focusing on challenging weight and intense effort is all that really matters.

    WRT the Tate protocol, I think he is experiencing a similar phenomenon that I describe above, although shifted toward the fast twitch end of the spectrum. The more genetically average may benefit from a little longer TUL. I also cannot refrain from commenting on Mr. Tate’s abysmal health parameters. I am not a big one for following cholesterol profiles, but his are particularly bad. I hope that he might focus more on the diet side of the equation and “go paleo” for the sake of his health. He already has more muscle mass than he will ever need. I think Mr. Tate is doing the right thing to shift his focus on body composition and overall health. Perhaps Keith could offer him some pointers.

    Doug McGuff

    • Great information, Doug, and devilishly interesting. Especially the notion of the “signature TUL”; I’d really like to see this idea explored further. Thanks for taking the time to elaborate on this subject.

      • n=1, but back around the age of 20, I developed a signature TUL on a Nautilus Nitro Leg Press. For a period of about 6 months, I reached fatigue within a 10 second window of 1:45, adding an average of 15lbs/month to the apparatus. I see this in clients as well; not every client, but some.


        • Any noticeable hypertrophy, or enhanced performance (aside from that particular lift) — i.e., transferability, as a result? I’m very curious about this “signature TUL” phenomenon.

          • I wasn’t participating in any sport at the time, so I don’t have any performance data in the regard. I remember a similar situation a few years ago; again, no performance data but I was consistently reaching fatigue at ~1 minute with a much heavier weight. Also within a 10 second window. Hypertrophy was improved, but I was also eating to support such gains; it was around this time I nearly reached my max “almost lean” weight (219lbs, ~15%bf). I contribute much to deadlifts as well during this time.

            For further wanking: I propose that there exists a signature TUL for any given percentage of max load. While I was able to add weight weekly (5lbs, if I remember correctly) and still fatigue at roughly 60 seconds. Call in the TUL equivalent of X rep max.

  6. This is a off-topic, but I just found your website and I was wondering what type of cardiac work-ups you’ve had done. I ask because I just saw formidable research the other day showing that people with good lipid profiles could have very bad calcium-scoring with significant cardiovascular risk. This was in relation to those doing long bouts of steady-state cardio, but the rationale was thought to be related to inflammation and stress so I am wondering about the sausages, bacon, etc. This isn’t a challenge, I was just wondering how things were looking on the inside for you.

    I look forward to reading your blog more in the future.

    • It’s been well over 2 years since I’ve been near a doctor, and so I confess to having no blood work to support my claims of being physically better off since adopting the Paleo lifestyle as my own. What I can say is that my blood pressure, which had been chronically elevated (140/90 – ish) since my teens, has now normalized (120/70, last checked). I can say that I dropped water weight and body fat seemingly overnight. I can tell you that my seasonal allergies are a thing of the past, and I can relay to you that I “feel” much healthier and have a much more stable energy level throughout the day. I realize these are mostly subjective measures, and I’ll take the hit for not providing any “hard” numbers to support my claims. I can promise that if I ever do make it back to a doctor, I will have my bloodwork done and I will post it — good, bad, or indifferent. For now though, I see no need to waste my money or precious time with a prolonged office visit, that, in my mind, will amount to nothing. 🙂

  7. Chris,

    I no longer check cholesterol as I think it is a downstream measure of an upstream issue that paleo addresses well.

    A couple of years ago I had several days of experiencing crushing chest pain radiating to my jaws that would last for hours at a time. Being a good doctor (shitty patient), I performed EKG’s and cardiac enzymes every 4 hours while I was working in the ER to rule out an acute heart attack. I then followed up with a 64 slice CT angiogram of the coronary arteries. I had completely patent coronary arteries that were described as “pipes” and a coronary calcium score of zero. The techs performing the procedure freaked out when my heart rate dropped into the 40’s. I had to convince them that this was my normal resting heart rate (they wanted to send me to the ER! doh!).

    Turns out the chest pain was from pericarditis (a viral infection of the sac that surrounds the heart). It got better after a day of ibuprofen.

    Doug McGuff

    • So we can conclude that the recommendations in Body by Science will lead to pericarditis? Ha, ha, just joking.

      Seriously, though, that’s interesting to know. Thanks for your reply. I’m going to order your book. I used to be a competitive swimmer and had a resting HR in the low-mid 50’s, although 12 years later I’m ~275lbs and have had aortic calcifications found on an echo. As I’ve finished schooling for a new career and have more free time, I hope to reverse these trends.

      I can get sold on fish and fowl pretty easily, but not so much sausage…

    • I always thought that lots of cardio would lead to a very low resting heart rate. When I ran cross country I had a relaxed-resting heart rate of around 55bpm ish, and I thought that was a could measure of cardiovascular health.

      Now that I strength train heavy once every 8-10 days, and incorporate sprints in once a week, and do zero steady cardio of any sort, my resting heart rate when sitting at a desk is 46-50 BPM on average. I guess all that cardio wasn’t necessary to achieve a low resting heart rate. My question is: Is a low resting heart rate actually a metric of good health?


      • I believe that resting heart rate can be used as part of a matrix of indicators of good health; surely it’s one measure of cardiovascular fitness. More so, though, I use deviations in average morning RHR and body temperature as indicators of overtraining (or, more particularly, overstress).

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