Time under tension - how important?

[Gregor]

Hi,

Some training systems claim that time under tension is the most important factor for muscle growth. Is this supported by any studies? I mean is it really important that you keep your muscles under tension for let's say 90 seconds or is total load/work the more important factor (as for example most obviously in cluster HST)?

 

[Sci]

Hi, Some training systems claim that time under tension is the most important factor for muscle growth. Is this supported by any studies? I mean is it really important that you keep your muscles under tension for let's say 90 seconds or is total load/work the more important factor (as for example most obviously in cluster HST)?

TUT is essentially the same thing as "volume". If you do 30 total reps of an exercise, that is a LOT more TUT then doing 5 total reps. Obviously if you do 5 reps very slowly, you will get more TUT than doing 5 reps quickly. But there is really no benefit to doing slow reps, as it is easier and more functional to simply do normal speed reps and do more total reps (sets) rather than do slower reps.

Is volume (TUT) important to hypertrophy? Yes. You are not going to grow doing only one rep per exercise. ALL the factors are important... Load, volume and frequency, and ideally HST is a balancing act of all of them.

 

[HST_Rihad]

Gregor, that's a question that I've been wondering about too, with no easy answer yet (different sources have come up with greatly varying time constraints, from as little as 12-15 seconds in some of them to about 45 seconds in others). It's probably wise to combine both higher load (4-6RM) high-tension clusters with higher rep (10-20RM) sets to cover all possible scenarios. I'm doing higher rep work myo-reps style, to provide additional time economy & probably dose/response benefits. There you can be quite confident that immediate TUT is long enough. Yet max-stim has you take 10RM load and do a series of singles with weight being racked and rest taken for 1-10 seconds after each rep (rest varies as fatigue accumulates), until you hit a total of 20 reps. So apparently a short rest after each rep isn't preventing us from piling up immediate TUT work. The secret is most likely to work just a tiny bit ahead of ATP replenishment and be able to almost totally exhaust it without other factors (lactate, etc) preventing you from doing so.

 

[Jester]

Rather than focusing solely on TUT, I would focus on achieving both a threshold of load, work done and then incorporating what is generally referred to as 'metabolic work' (high rep work, anything 80kg12+, ideally 15-20 range).

You need a certain amount of load, relative to the muscle you're applying. No number of 15RM sets at (just a guess at what it is -->) 80kg is going to provide fiber growth in an experienced trainee who has a 1RM of 145kg. He/she will still need to be achieving a load sufficient to cause the microdamage that functions as a stimulus for fiber hypertrophy.

Research is increasingly showing the relevance of work done as well. This might be referred to TUT, and they're probably acceptable as interchangeable terms, although many people confuse/mix up TUT between literal TUT per rep, and total TUT per work out. Several studies have shown that significantly slower rep speeds (especially on the eccentric) will negatively impact your neuromuscular capabilities (essentially you're training your body to lift less efficiently, whilst increasing the TUT. Not a great trade off when requisite TUT can be achieved by other means).

Max-stim is a very good training technique. It's function (although not its stated purpose) is to essentially the spare the CNS, and hence allow you to achieve a greater TUT without significantly impacting your CNS and hence your ability to maintain and not impede your training frequency.

Regarding the high-reps, there's no proven significant advantage to how you perform them; whether separate and after your higher-load work sets, whether you do them immediately after as drop sets or whether you do them as myo-reps. For my money, separate sets is fine. I would also not do them for squats or deadlifts, as the high-rep work can be extremely exhausting. In fact, I don't think I've met anyone who enjoyed (or flourished due to) high-rep deads. They will certainly factor into accumulated CNS exhaustion and should be applied with this in mind. The high rep work also provides extra energy expenditure. You should factor this into your diet accordingly. And lastly, if you aren't eating enough to gain (whatever that number is/you determine it to be), I would forgo the high-rep work. They're of little use to someone who is cutting, unless you want to use them as a way to create/assist in creating deficit - but that benefit will be offset by general lack of sustained glycogen storage, slower CNS recovery due to caloric deficit and the impact of reduced recovery on sustaining stimulus frequency (i.e. not skipping days because you're too tired from previous session).


I've been training w/high-load clusters + high rep work for about 7 years. I've taken training breaks along the way, but it is by far the most effective way to train that I've experienced. Max-stim is a technique I now include, although I push the relative load and extend the M-time longer than most. Putting Max-stim aside, it's really just a simple way to train; lift heavy(ier) to provide threshold tension/load, lift frequently for maximum bouts of stimulus production, perform a work load (rep total) that allows you to perform the next workout satisfactorily.

Most important though is diet. If you aren't eating sufficient calories, your body will not gain weight. It does not try to build muscle whilst losing fat. The former is an incredibly energy inefficient process and is perhaps analogised as trying to increase government revenue whilst reducing taxation - go figure how well that works. That isn't to say you need to stuff-your-face-full at every chance, but you can't hope to build muscle on a caloric deficit. Determining what your surplus-maintenance-deficit actually are is a different conversation, but at the end of the day, if you aren't gaining weight then you aren't gaining weight.

 

[adpowah]

Determining what your surplus-maintenance-deficit actually are is a different conversation, but at the end of the day, if you aren't gaining weight then you aren't gaining weight.

Nice post, but I appreciated the simplicity and truth of the last statement.

 

[Gregor]

Thanks for all the answers. Great info.

But what I actually meant by TUT in this context was uninterrupted time under tension. I don't work in a job for which I need to be strong (mainly an office job) and I don't regularly do other sports anymore which would demand specific muscular requirements like explosive strength or strength endurance. Therefore, I just train for looks now (and a bit for general fitness).

Some sources (I would have to dig them up again to quote them) say that an effective stimulus for muscle growth requires a certain uninterrupted TUT. If heavy loads and total work are the most important factors, then instead of doing a set of 90 secs duration without interruption I could split this set up into smaller bits like 3 x 30 secs for example and it would not lessen the effect as a hypertrophic stimulus (muscular endurance is a different matter but this is not my priority). Is this correct?

 

[Sci]

Thanks for all the answers. Great info. But what I actually meant by TUT in this context was uninterrupted time under tension. I don't work in a job for which I need to be strong (mainly an office job) and I don't regularly do other sports anymore which would demand specific muscular requirements like explosive strength or strength endurance. Therefore, I just train for looks now (and a bit for general fitness). Some sources (I would have to dig them up again to quote them) say that an effective stimulus for muscle growth requires a certain uninterrupted TUT. If heavy loads and total work are the most important factors, then instead of doing a set of 90 secs duration without interruption I could split this set up into smaller bits like 3 x 30 secs for example and it would not lessen the effect as a hypertrophic stimulus (muscular endurance is a different matter but this is not my priority). Is this correct?

Uninterrupted TUT is only important when using relatively low loads, so as to maximize fiber recruitment. When using any load approx. 8RM or heavier, you are getting full recruitment the whole time.

If you are using lighter loads, like a 12-15 RM, then keeping tension on the muscle the whole time will help fatigue muscle fibers, resulting in full recruitment, toward the end if the set.

Myo-reps was developed by Borge Fagerli to do this. Normally doing 15 straight reps to failure, only the last few reps get full fiber recruitment. With myo-reps you stop near failure, take a few breaths and keep doing reps with the muscle in a fatigued state, so as to get full recruitment. TUT as you describe is really not important, I don't know where you got that info? Can you state the source, research papers?

 

[HST_Rihad]

Nice post, but I appreciated the simplicity and truth of the last statement.

"Eating enough" shouldn't be read to mean "eat to gain a pound of BW a week". What kind of growth would that be? Fiber growth happens at a small rate in comparison to BW growth. Gaining "weight" while resistance training should be done carefully, I'd say 200 gr / half a pound weight gained in a month (except at beginner stage)!

 

[Jester]

You're making the presumption that "carefully" needs to be "slowly".

There's also the problem of certifying/confirming a weight gain of 200gms, not to mention trying to determine what % of that is glycogen-water, what % is fat, what % is fiber growth.

A pound a week? Certainly excessive. If we were all capable of gaining ~220gms of LBM a month (let's assume 1:1 p-ratio for sake of argument) then there wouldn't be a lot of need for forums such as this one. However, identifying an over-estimation at one end of the spectrum shouldn't lead to making an under-estimation at the other.


I think in general the pragmatic and sensible way to do it is measure your weight constantly. If it isn't going up across weeks (not days, weeks), in terms of certifiable measurements, then you aren't eating enough. If your waistline is similarly expanding, then you're eating too much.

Regardless, muscle is the most energetically inefficient tissue to build. It takes less energy to build and sustain bone than it does muscle (yay calcium, thank you for the hard work you're doing). Entropy and enthalpy dynamics can't be cheated either - we have to eat more than we use for sustenance, and that surplus goes to building new tissue. The surplus required is (by relative comparison) v.high, but in real terms it's probably in the realm of 300-500kcals (or food cals) per day. How accurately can we make that a reality when factoring in daily energy expenses? That's the real trick.

But the principle applies no matter what; if you aren't gaining weight, you aren't gaining weight.

 

[HST_Rihad]

It's quite easy to not let BW fluctuate between early morning measurements if you make it a habit to eat at predetermined times every day. 300-500 kcals daily surplus will simply pile back up the extra weight you had to cut in the first place, with no correlation to muscle protein tissue itself, except in sarcoplasmic hypertrophy the food we eat goes to refill glycogen storage in muscles too, and if we eat extra on a continuous basis, it most likely will stay there being part of the size of the muscle together with the overall fat, in proportions determined by individual p-ratio. It wouldn't be totally unrealistic that having sarcoplasmic hypertrophy from day to day doesn't require us to constantly overeat for the simple reason that fat is designed to store surplus and is practically limitless, while muscle glycogen has a notion of depleted/full. So all we need to do is to somehow deplete muscle glycogen to some degree (using intermittent fasting, for example), and then load up carbs which would be most likely to get stored there by insulin, because muscle "needs" it and is sensitive to insulin. I will try experimenting with this later when I'm finally done cutting.

 

[Jester]

It's quite easy to not let BW fluctuate between early morning measurements if you make it a habit to eat at predetermined times every day. 300-500 kcals daily surplus will simply pile back up the extra weight you had to cut in the first place, with no correlation to muscle protein tissue itself

The source of many of our disagreements on these forums (or rather, outstanding disagreements, as you've finally come around on how to train for size, at least according to your initial response to OP in thread ... anyway), is that you haven't justified this premise (lack or near-lack of significant caloric surplus) with anything resembling scientific data or even mass-anecdotal data.

It's all conjecture and theories. Some of your ideas are quite logical, but they don't possess exclusive-logic (ala they are opposed by equally logical theories/essentially proven/borne out scenarios) and until you back them up, it's just you firing off your flavour-of-the-week idea.



Related but unrelated: if you want to deplete muscle glycogen; exercise. Fasting is not a particularly efficient way to do it.

"Overeat" - this doesn't mean stuff your face like a pig. It means eat beyond what is required to maintain your body weight. Your body doesn't want to building muscle when it's calorically starved (to use common vernacular), and why would it? If the tissues you have are suffering from an energy deficit, why use protein (or any calorie source) to build MORE tissue (that will also be energy starved) as opposed to using those calories to meet energy needs?

If there's some leftover, great, you're in surplus already. If it isn't enough, you're in deficit.

 

[HST_Rihad]

Fasting along with external activity is an obvious way of depleting energy sources (in fact, both our BMR and exercise *are* activities). Moreover being sensitive to insulin means that insulin is more likely to bind to a muscle receptor and store glucose there, and fasting is a normal way of decreasing blood insulin concentration, thereby increasing sensitivity to it.

Tissue doesn't need as much as 500 kcal surplus for energy or material. Surplus is a stupid term anyway because we don't live in a lab environment calculating all our intake and expenditure with great precision. This is life, the fact that body tends to maintain its body weight during what we call "eating for maintenance" is simply because this is what it tries to always do - maintain homeostasis, and not because of our meticulous attempts to hit a macro goal to the gram. Only when we decide we're smarter than our bodies and rapidly start shoving in an extra 500 kcals (we're bulking, bro) it hasn't yet grown accustomed to, will it begin to store the excess as fat. It's that simple. We only need to cover our expenditure of what has already taken place, we *don't* need to overeat in advance.


Body is very good at optimizing resource usage, not initially, but it always tries to gradually adapt to whatever environment we put it in. From someone's calculated "maintenance" 2200 kcals body can always steal a few grams of protein and use it as material, because that's one of the things it needs to take care of. Trying to judge if we're making size progress or not shouldn't be based on a weight scale because it's an easy trap to fall into.

 

[Jester]

We only need to cover our expenditure of what has already taken place, we *don't* need to overeat in advance.

If you've done the training properly (i.e. provided the stimulus), it isn't in 'advance'. I can't recall suggesting this, not anyone else here suggesting it. Both on the micro and macro scale, your energy needs increase post-stimulus, not pre-stimulus.

Surplus is a stupid term anyway because we don't live in a lab environment calculating all our intake and expenditure with great precision.

The term is perfectly apt and not the least bit stupid. You might be unhappy or disagree with what it's definition ought to be commonly used as, but the term itself is perfect for the relative caloric intake it refers to.

To build tissue, any tissue, you need the energy to do it. You can't preferentially direct your energy supplies (food, fat) to build muscle when your bodies energy pathways are telling it that it needs to maintain (homeostasis) the status quo (i.e. conditions are implying its starving). Building muscle is an incredibly energy inefficient process, and not something that complex life does very well. Skeletal muscle in humans is no different. Your body doesn't 'want' excess muscle. It (the excess, in its literal meaning of 'beyond necessity') requires extra energy to maintain, isn't particularly useful in Darwinian terms (think speed impact, flexibility impact, bigger target, increased vulnerabilities, increased requirements for food and water) and doesn't serve a function not otherwise provided by adequate (existing) skeletal muscle. We train to tell our bodies we need what it currently considers 'excess' (those aiming for hypertrophy, that is).


My personal opinion is that much of your position is biased by your poor experiences bulking in the past - it's coloured your viewpoint and led to generalisation and self-satisfied logical connections, rather than scientifically established outcomes. Not to say you're an idiot - you clearly aren't. But you're ice-skating up hill if you think you can cause the conditions needed for fat loss and muscle growth simultaneously, and also implement both of those processes simultaneously. You over-ate on your bulked and definitely didn't train optimally (or close to optimal). Doesn't matter, you're on the right side of 40. Just don't waste a decade going for 're-comping' and come out a still-average size in the end.

There's a reason that surplus-deficit-repeat has worked for so many people, thousands of them.

2200 kcals body can always steal a few grams of protein and use it as material, because that's one of the things it needs to take care of.

No, it isn't something that needs taking care of. Sustaining what muscle it has? Yes. It will use amino acids to maintain the muscle it is (when in deficit/maintenance). It will not build new muscle if it can't energetically afford to. If you cut the training and maintain the eating, you'll get fatter and lose muscle. This is not 'catabolic', as some would argue. It's merely the lack of stimulus required to maintain the muscle mass and current homeostasis resulting in the (always present) muscle degradation processes winning out (ala your muscles are building and degrading at the same time, all the time, it's merely a matter of where the ratio is at - hence why we provide a stimulus -> being resistance training). You don't need the extra energy that you previously did for muscle building, expenditure and system maintenance, so your body doesn't the most energetically efficient process it knows and whacks those lipids into fat cells.

I agree that a scale is not the only measure you should use to judge LBM gains. However, it certainly should be one of them, and its most apt use is to judge whether you are caloric surplus or deficit. If you aren't gaining weight, you aren't building muscle. Sustaining? Sure. Gaining? No, not unless you have substantial fat stores - say bf = 25% plus at a minimum). If you're eating too much, you aren't giving your body any reason to burn it's valuable fat stores. Those stores are the result of thousands upon thousands of evolutionary processes that there for the day when you don't have food and your tissue doesn't want to die right away because of that. They're not there to build muscle when you have no food, and they don't get used as such by any of the energy pathways available, at any (as yet) measureable or significantly relevant magnitude. If they did, we'd all be shredded and bigger.

Surplus? Yes, you need it. As I said, what your/anyone's necessary surplus actually is - that takes figuring out.

 

[HST_Rihad]

Building muscle is an incredibly energy inefficient process, and not something that complex life does very well. Skeletal muscle in humans is no different. Your body doesn't 'want' excess muscle.

Oh, come on. The mechanism of protein breakdown/resynthesis is something that always occurs, whether we train or not. Growing muscle bigger (or generally getting better at something) is what body does to withstand future bouts of stress it's been exposed to. The wizardry is built in. No matter how undernourished you are if you accidentally let a carelessly tossed dumbbell cut through a small piece of your finger skin & some meat, body will start its recovery process lasting for a few days/weeks (depending on severity), after which... no you won't get a bigger finger - but the the look & feel of it would have been 100% restored. You don't need to be eating at a surplus (or even at maintenance!) for that.

We train to tell our bodies we need what it currently considers 'excess' (those aiming for hypertrophy, that is).

Or, quite similarly, what we've trained isn't considered excess, it's our daily expenditure that we'd better cover if we don't want to lose weight.

You over-ate on your bulked and definitely didn't train optimally (or close to optimal).

This is true.

Doesn't matter, you're on the right side of 40.

Age doesn't really matter, 60 year old people who've been training since their teens lose what, 5% of their mass?

Will answer the remaining in a while, need to go cover some expenditure

 

[HST_Rihad]

as you've finally come around on how to train for size, at least according to your initial response to OP in thread ... anyway)

Not really, I haven't changed my mind. It's just that technically, it's nearly impossible to hit maintenance. We're always off in either direction within any time frame. If the discrepancy is negligible body somehow tries to maintain homeostasis. I've been eating sensibly day after day without calculating anything, and my body weight has stayed stable for the past 3 months. If body does its job maintaining BW this easily, replacing damaged body protein fibers seems to be a snap to fit into that. The body HAS to replace tissue damaged by workouts anyway, so if it perfectly does it, and I'm on a deficit, why can't it simply make it a tad bigger? So it's mostly now a function of adequate load/volume.

 

[Bulldog]

Not really, I haven't changed my mind. It's just that technically, it's nearly impossible to hit maintenance. We're always off in either direction within any time frame. If the discrepancy is negligible body somehow tries to maintain homeostasis. I've been eating sensibly day after day without calculating anything, and my body weight has stayed stable for the past 3 months. If body does its job maintaining BW this easily, replacing damaged body protein fibers seems to be a snap to fit into that. The body HAS to replace tissue damaged by workouts anyway, so if it perfectly does it, and I'm on a deficit, why can't it simply make it a tad bigger? So it's mostly now a function of adequate load/volume.

It doesn't work that way. If you stay on a deficit for a long period of time you will eventually lose muscle mass. There is no way around it.

 

[HST_Rihad]

It doesn't work that way. If you stay on a deficit for a long period of time you will eventually lose muscle mass. There is no way around it.

I've lost in sheer size, no doubt. A little over an inch in arms, among others. But did I lose in bicep curling strength? Not at all. So most likely none of that was contractile elements, but was connective tissue, water, fat, glycogen, and whatnot (inessential LBM). Will I eventually lose strength/contractile elements if I continue dieting while training? After more than 8 months, most likely not.

 

[Jester]

Not really, I haven't changed my mind. It's just that technically, it's nearly impossible to hit maintenance. We're always off in either direction within any time frame. If the discrepancy is negligible body somehow tries to maintain homeostasis. I've been eating sensibly day after day without calculating anything, and my body weight has stayed stable for the past 3 months. If body does its job maintaining BW this easily, replacing damaged body protein fibers seems to be a snap to fit into that. The body HAS to replace tissue damaged by workouts anyway, so if it perfectly does it, and I'm on a deficit, why can't it simply make it a tad bigger? So it's mostly now a function of adequate load/volume.

The body doesn't have to, actually. Not all damaged muscle fibers are restored to their previous size; it depends on the amino acids and calories available.

In the end, you're still asking the wrong question. It isn't a matter of "why can't simply make it a tad bigger?", it's a case of "why would it make it a tad bigger?". There's no reason for an organism that is calorically deprived (deficit) to increase it's size. It's basically evolutionary suicide, the equivalent of a bankrupt company taking on more staff and sending out purchase orders for equipment and supplies it can never fulfill.

I've lost in sheer size, no doubt. A little over an inch in arms, among others. But did I lose in bicep curling strength? Not at all. So most likely none of that was contractile elements, but was connective tissue, water, fat, glycogen, and whatnot (inessential LBM). Will I eventually lose strength/contractile elements if I continue dieting while training? After more than 8 months, most likely not.

Why would you lose connective tissue (tendons) and ligaments but not fiber tissue? You didn't lose bicep strength because your neuromuscular connection is far more efficient now than it was 8 months ago. Your muscles are capable of far more strength than you realise. If you run the correct current through them using an electrode, they'll snap your limbs in half and tear tendons from the bone; that's how strongly they're capable of contracting.

Did you lose much muscle? Likely not. Your resistance training is keeping the stimulus high enough that despite your deficit, it's been a minimal loss. But it's still a loss, and no gains were made.

 

[adpowah]

"Losing fat and gaining muscle" is the el Dorado of working out. Once I made that mental adjustment I've been able to make better gains than I ever have. Cutting sucks and bulking kind of does too but it offers results. Maybe there are people out there who can do both at the same time but it wasn't me and when I stopped acting like it was me, I saw results.

 

[Sci]

"Losing fat and gaining muscle" is the el Dorado of working out. Once I made that mental adjustment I've been able to make better gains than I ever have. Cutting sucks and bulking kind of does too but it offers results. Maybe there are people out there who can do both at the same time but it wasn't me and when I stopped acting like it was me, I saw results.

Amen to that. Same experience here.