Is Time Under Tension (TuT) a myth?

By Marwan / July 1, 2014

What is Time Under Tension or TUT and is Time Under Tension a myth? Time Under Tension refers to amount of time the muscle is constantly under tension within a set, usually measured in seconds.
As ever in the bodybuilding community you will talk to those who swear by it and those that think Time Under Tension is a myth. Well, have a read below and judge for yourself.
Before you choose a TUT period you first need to determine what your goal is, by that I mean increase strength, improve endurance, or build muscle?
The graph below shows you how the different energy systems and time spent under tension go hand in hand in creating a training effect.

Energy systems used with Time Under Tension

Time under tension is calculated in the following manner:

[Eccentric time(sec) + pause time(sec) + concentric time(sec)] x no. of reps in set = TUT

The following is a working example of this calculation:

[3 sec ecc + 1 sec pause + 1 sec ecc ] = 5 sec x 8 reps = 40 seconds of TUT

In the table below I show you how the amount of time the muscle is spent under tension uses different training methods and adaptations.

If the average tempo is 321, the TUT is 6 seconds per rep, and if the average number of reps is 10, the average duration of TUT per set is 60 seconds or 1 minute.

eg.       321 = 6 seconds

            6 secs x 10 reps = 60 seconds

Time Under Tension is very misunderstood in the bodybuilding community.  Here is a basic breakdown of how it works, (Ian King and Charles Poliquin were the two who advocated TuT)

The amount of time that you have a muscle under tension determines the anabolic response that will elicit in the body.  I have done a small table below to explain it better;

Time under Tension                    Dominant Effect                          Rep Range

1-20 Seconds                                          Strength Training                                1-5 Reps


20-40 Seconds                                      Functional Hypertrophy/                6-8 Reps

Strength Second


40-70 Seconds                                      Hypertrophy/ Functional

Hypertrophy Second                         9-12 Reps


60 Seconds +                                          Endurance                                             13 Reps+


So, if your goal was hypertrophy i.e. build muscle, optimally you need to put the muscle under tension between 40-70 seconds.

If your goal is strength then 20 seconds of time spent under tension is all you need.

The above is not set in stone.  You can still train in the 1-5 reps range and put the muscle under 40 seconds of constant tension by manipulating the variables.  A ,lot of the variables described above will overlap so just because you are doing 8 reps that does not mean you are not getting stronger.

Inevitably the more you put the muscle under tension the more DOMS you are likely to get as you are breaking down the muscle fibers.

The faster the rep is completed the more force is generated but with less tension, the slower the rep is completed the more tension there is but less force.  As tension increases force decreases and vice versa.

That is why slowing down the weight on the eccentric part of the lift is better for hypertrophy as more tension is created with less force.

  1. An explosive concentric will generate maximal force with little tension
  2. A slow concentric will generate greater tension but with less force
  3. An isometric contraction will generate greater tension than a concentric but will generate less force
  4. An eccentric contraction will generate maximal tension with the least amount of force.

What this means:

For Strength Training (Neural Adaptations) you should lift explosively because force generation is the goal with little attention being paid to the amount of tension created on the muscle.

If Hypertrophy (sarcomere) is your goal you should lift slower because the goal is to create a lot of tension on the muscle, the focus should be on trying to squeeze the muscles as hard as possible to create that tension.

So to summarize the above, improvements in force generation improve strength, increasing the amount of tension on the muscles creates hypertrophy.  You need to incorporate both styles into your programme.

One of my favourite ways to keep the muscle under tension is using the rest pause method.

Basically when I get to failure instead of terminating the set, I drop the weights by 10% and go to failure, drop the weights by 10% and go to failure again (preferably you have a training partner with you so you can minimise the rest period).  Then depending on how I feel or how much more time I want my muscles to be under I might do another drop set.

That’s it folks, next time you see guys or girls in the gym throwing weights around you can show them this article ;) and tell them that Time Under Tension is not a myth.

As always if you have any comments leave them below.



About the author


Hi, my name is Marwan and I set up this site to help skinny guys and girls just like you to end their frustrations and have the body of their dreams. I believe there are no limitations to what mankind can achieve.