T Nation

The TUT Principle


Okay, I know this sounds moronic, but I am serious.

Why do we as trainees even have to move the bar up and down? According to the Time under Tension principles should't it be enough to be in a flexed position for 30 to 75 seconds?

e.g. Barbell Curls: grab a 80 pound bar move it up till your arms are at about 90 degress and wait in that flexed position till your bis cannot take it any more.


Why not try it out yourself if you think it would work? Come back six months from now and with some pictures of you progress and let us know how it went.

Seriously, why try to re-invent the wheel when the version that is already out there works quite well?

Peter Sisco and John Little already tried to market this type of training ("Static Contraction training"). To date I honestly can't think of one person who has built an impressive physique using this program (or method) exclusively.

That should probably tell you something. :wink:

Good training,



Range of Motion. By keeping that bar in one spot, you're not going to work as many muscle fibers.


I read a piece Sisco did on SCT and found it intriguing, but like you say that little voice tells me that this isn't going to be real productive as a program.

On the other hand I've toyed with the idea on occasion of doing like a single week just to see what I thought. This could be a use for the Smith Machine (the other thread), load up like 125% of 1RM, set the stoppers and do it like a one giant eccentric rep holding on as long as possible. Of course while praying for your knees.


Yeah, the concept actually isn't that far fetched, which is why I think that many people get suckered in by it. Same as "Power Factor" training. Sisco makes a great argument for it in the book and quotes some pretty impressive names as to the benefits of using partials.

And, while I still think that using supramaximal partials or static holds could be beneficial if used sparingly and infrequently, I still feel that you can't really build an entire system around them.


I actually tried the Static COntration Training years gago with a training partner of mine. We'd load up the bar in a power rack, unload it and hold it halfway in a benchpress fashion with way more weight than we could actuzally move up and down. USing a stopwatch we;d time how long we could hold it each week. We did get sore, and yeah, teh #s went up, but nothing we really wanted to happen did (growth?!). I read afterwards (dont recall where), that you actually need some movement for an exercise to be productive. I know that doesn't sound very technical, and I wish I could recall the exact argument, but it made me think that static holds would likely be a great way to extend a regular set (burn outs?), but not as a core training method.

Just my thoughts.



Its a misapplication of the principle. Doing that is the same as taking the heavy lifting principle and only ever doing 1 rep maxes, you wont get anywhere. The point with TUT is that it is very necessary for maximal growth, but you can take the concept too far.

For instance you could use the constant tension principle and do 12 reps of incline dumbell press with 20lbs and take 20 seconds for each rep. Of course this would be very difficult and you have alot of TUT but there is a minimal threshold of weight needed to elicit muscle growth, and if you are using too low a percentage of your 1rm your body will get better at buffering lactate and recruiting slow twitch fibers because what you are asking out of your muscle is endurance not strength.

Also, like another poster said you need to work through your full ROM to maximally stimulate the muscle you are working. You need to find the sweet spot with your tempo and feeling the muscle work. Then, keeping that in mind, use the heaviest weight you can use. You be using quite a bit less than usual.


TUT is not everything. Yes, muscles burn energy just to stay flexed, but more energy is being spent if you actually move the bar. The stimulus is greater.
Also, probably not enough fibers are recruited if you don't actually move.


Nothing is everything


Isometrics are useful for some things, athletically and for muscle growth. I have used isometrics, specifically yielding isometrics (like you described, holding a position rather than pressing against an immovable object), a lot in my lower body training with success. I feel like they have served a great purpose and as a bit of a side effect, I have very well developed legs.

Some exercises lend themselves better to this than others. I have probably had the most success with weighted Bulgarian split squats, picking a heavy weight that I could only hold for 20-30 seconds or so. I attribute them to helping put a lot of size on my legs.

Interesting study on yielding isos:

During submaximal eccentric, isometric, and concentric voluntary contractions, the AL increased linearly with increasing tension level. The significantly weaker slope of the AL-torque relationship obtained during eccentric contractions indicates that the voluntary activation reduction is not limited to maximal eccentric efforts but may be an inherent characteristic of the command to activate lengthening muscles voluntarily.

It, therefore, supports the fact that, during eccentric contractions, less neural drive (number or discharge rate of the motor unit) is needed to develop a given submaximal muscle tension (8). Identical findings have recently been obtained on human soleus muscle using a different technique, i.e., comparison between submaximal electrical activation and maximal and submaximal voluntary efforts (30).

Nevertheless, according to Pinniger et al. (30), this activation reduction would happen at least for torque levels >30% of the MVC and not for the whole eccentric torque range. The reduction of the motoneuronal excitability during eccentric contractions (31), possibly originating from presynaptic inhibition changes, may explain this result.

Indeed, it has already been reported that, during submaximal lengthening contractions, high-threshold motor units may be preferentially activated (27). However, contrary to the eccentric condition, submaximal concentric efforts indicate a similar relationship to that fitted during isometric contractions. Such similarity has already been observed using short trains of stimuli (28).

Thus a discontinuity between submaximal and maximal concentric contractions is revealed that is probably due to different neural mechanisms intervening in the activation regulation for the different tension levels. "

The study can be found at the following link