The "Time under Tension" is a term that is often used in relation to effective training and especially in connection with muscle growth. Here you can find out what is behind the term and if it really plays such a big role.
What is Time under Tension?
Time under tension (TUT) usually describes the time your muscle is under contraction (tension) while you are doing a training set. So if you need 3 seconds for one repetition and want to do 6 repetitions, your set will last 18 seconds. This means that your time under tension is 18 seconds. But if you do only 3 repetitions with 6 seconds each, you will quickly notice that you also need 18 seconds. The time under tension is therefore the same for both variants.
But why is that important? Time under tension is an important factor in determining what stimulus you apply to your muscles and what training effect you achieve with it. The following guidelines therefore apply to the TUT. The optimal duration of tension (TUT) for an increase in maximum strength is 4 - 20 seconds. The optimal duration for muscle growth is 40 - 60 seconds. Anything that goes beyond this is then directed at the area of strength endurance. You may ask yourself: "But what about the repetitions? Don't they matter at all? The answer is a clear yes. As you may have already noticed, 1-6 repetitions as you know them from maximum strength training correspond to approximately the described 4-20 seconds of TUT. In the same way, for 6-15 very controlled repetitions of an exercise, you probably also need the 40-60 seconds required for training to build muscle. You reach your time under tension mostly indirectly by the corresponding number of repetitions. TUT and the repetition range are closely related. But if we are completely honest, it often happens that even if we do 12 repetitions in one exercise, we do not reach the required 40 seconds or more. This can become a problem if you constantly fall below the required time under tension in your training. Surely you can build some muscle, even if you have never needed 40 seconds for a set, but you should ask yourself how long you actually need for a work set. It is possible that you are still leaving a lot behind in your training and you can set new stimuli with another TUT.
How do I stick to the Time under Tension?
Since it is impractical to let the stopwatch run during every set, there are some tricks or methods you can use to make it easier for you to keep the correct TUT.
In strength training, cadence is the speed at which you perform the individual partial movements of an exercise. As an example you can use the following sequence of numbers: 2-1-2 Example: Cadence 2-1-2 while bench pressing:
2 seconds = lowering the bar onto the chest
1 second = barbell is held
2 seconds = barbell moves up
If you follow the guidelines, you will need about 5 seconds for one repetition and you will get 50 seconds time under tension in a set of 10 repetitions and you will be in the optimal range for muscle growth. However, this does not mean that you always have to stick to exactly this sequence. At this point there are a lot of variations that you can build into your training. For example you can use 4-2-4, 6-2-6 or 3-1-3 as a scheme, depending on which part of the movement you want to focus on. What is important is that you focus on the area between 40 and 60 seconds.
Another way to extend the time under tension is to use half reps, which you can add at the end of a set to "artificially" extend the TUT. We stick to the example bench press. When you have finished your target number of repetitions, you will then perform further repetitions in which you lower the bar only by half to the chest.
Please keep in mind, that training is ultimately about progressively overloading the muscle, which means to set a training stimulus with each training session, which animates your muscles to adapt. You can usually achieve this overload with the right combination of weight, repetitions and sets without having to constantly monitor the time under tension. However, it can be a good approach to pay attention to how long you keep your muscles under tension during your workout in order to develop a feeling for the range of time under tension you are in. So you can use the Time under Tension as a kind of intensity technique by using one of the described techniques. The Time under Tension is not the ultimate solution that many people have made it into, but it can improve your training and set new stimuli. As you can probably imagine, it doesn't do much to keep your muscle under slight tension for 60 seconds. The tension and the weight as well as the movement must always be right.
Criticism of the Time under Tension approach
The concept of Time under Tension sounds very plausible and suggests the idea of only stopping the time of tension from now on and performing the movements as slowly as possible. This approach is followed in the so-called Super slow Training. Even though the TUT has been investigated in many studies, from which the mentioned guideline values were also developed, there are still study results which do not suggest to orient exclusively on time under tension.
The following studies give the justification to question at least the effectiveness of Super slow training. Researchers at the University of Oklahoma, for example, came to the conclusion during a four-week study that Super slow training achieved worse training results with the test subjects than with an "ordinary" training approach. The University of Sydney also found that the subjects who trained "normally quick" could improve their performance faster than those who did particularly slow repetitions.
So it can not be assumed that a training with a particularly high time under tension leads to better results than usual training. As is so often the case, there are quite contradictory results and you should always get your own picture on the current state of knowledge.
The time under tension and its role in training success can be confusing and not entirely uncomplicated. It can be said that there is an optimal range of tension duration in which to train in relation to the training goal. However, since the comparison between Superslow training and ordinary training has shown that a focus on TUT alone does not lead to better training results, one should be very careful to consider TUT as the benchmark of all things. A sensible approach would be to use the concept of time under tension to vary your training. Good training always consists of a variation of weight, number of repetitions and the correct execution of movement. So if you've completely ignored the duration of your movement so far, it's helpful to incorporate it into your workout as another adjusting factor. So test if your TUT is possibly very short and if you can set new training stimuli by extending the TUT.
Even though the TUT plays an important role in training, you don't have to pay attention to the second. You should be aware, however, that people often tend to perform movements too quickly in a set and thus significantly shorten the TUT. The TUT is therefore not the only important factor that is important for your training, but it is one of them. So you should use it to further refine and improve your training.