Temps sous tension "TUT"

Ayant vu à plusieurs reprise dans le forum que l'important est la contraction du muscle et qu'il faut que le muscle soit sous tension durant un certain laps de temps, j'ai effectué quelque recherches.

Voici une partie d'un article de Charles Poliquin. (En anglais malheureusement car je n'ai pas trouvé de traducteur en ligne assez performant)

Citation :

The “Time-Under-Tension” Principle
Muscle growing isn't just about reps and rest periods. It all comes down to something called "time under tension". In some circles, time-under-tension refers to the amount of time you spend tailgating that Ford Pinto that's doing about 45 in the fast lane. It also refers to the time your muscles are actually working and weight, sets, and reps all play a part in the equation. For instance, if you do a set of 10 reps, but you pistoned them up and down like the pelvic thrusts of one of those horny baboons in a National Geographic special, your total time under tension was about two seconds. Muscle is not going to grow when your time under tension is inordinately low (see the next principle for more info on "time under tension").
Typically, and depending largely on your muscle fiber ratio (some people have more fast-twitch fibers than slow or vice versa), your time under tension should be anywhere from 30 seconds to about 70. Any more or any less is counterproductive over the long run. (Determining your exact muscle fiber make-up is probably a little more complicated than we want to get into here in this article).
As you progress from one set to another and you tire, you have one of two choices: reduce the weight, or reduce the number of reps. Given that choice, you should always reduce the weight and keep the rep range the same or roughly the same. In other words, if you just did 8 reps at 200, you'll need to reduce the weight about 4 or 5% on the next set in order to do 8 reps again.

The “Change the Beat Around” Principle
In the previous principle, we talked about time under tension and we mentioned the wisdom of keeping the duration of a set somewhere in the 30 to 70 second range. How do you do that without doing 30 to 70 reps? The answer is something called tempo. For instance, if I'm doing sets of dumbbell bench presses for sets of 4 to 6 reps, my time under tension is going to be something like 15 seconds if I do them at "normal" speed. However, if I slow them down, particularly on the eccentric, or lowering part of the movement, I'll increase time under tension.
Whenever you look at a Poliquin workout sheet, you'll see numbers that look like 302, or 501, or something similar. They do not refer to different styles of Levi's jeans. Instead, they refer to tempo, and the first number indicates how many seconds you should take to perform the eccentric portion of that particular lift. For instance, a "5" means you should take a count of five to lower the weight. The next number refers to the pause taken between the eccentric and the concentric portion of the movement, while the last number refers to how long it should take you to raise the weight.
Okay, so what this means is that if you're working in a 4-6 rep range, you have to adjust the tempo in order for that set's time under tension to reach at least 30 seconds. Along the same lines, if you're working in the 8-10 rep range, the tempo should be a little quicker so that you won't exceed the 30 to 70 second time-under-tension frame.

Je me suis basé sur ces données pour ma dernière séance. Les perfs ont été moindre du fait du rythme plus lent. Mais les sensations ont été au rendez-vous !!!
Je me suis basé sur les 40 à 70 secondes donnés par Proforce, mais sur certains mouvements (le développé militaire par exemple) il a été difficile de dépasser les 30 secondes.

Voici un lien sur une discussion sur ce point précis :

http://www.t-nation.com/tmagnum/readTopic.do?id=515288

Voici un extrait :
C. Thibaudeau

Citation :

Well, first of all, hypertrophy is first and foremost a question of muscle loading and force production. The magnitude of intramuscular tension is thus the most important factor in stimulating an hypertrophic response.

Intramuscular tension is a function of the force that has to be produced by the muscles which itself is determined by the good ole F = ma formula.

Both Weineck and Rhea et al. (2003) have found that once a trainee is past the beginner stage, an external loading of less than 80% of his maximum doesn't lead to optimum gains. For an advanced athlete, it's probably even higher than that.

Now, time under tension *is* also of significance when talking about hypertrophy. However I think that the *total* time under tension of a muscle is more important than the time under tension of each individual set. So you can increase TUT either by increasing the length of each set, or adding more sets.

Furthermore, I think that it's a bit simplistic to categorize training goals into TUT categories... 1-20 seconds for relative strength, 20-40 for functional hypertrophy, 40-70 for total hypertrophy, etc. While these might give us a good basic guideline to follow, we shouldn't follow them to the "T". The true ideal TUT will vary depending on each individual.

As I see it...

1) Start by selecting the appropriate load for maximum hypertrophy (something like 70-80% for beginners, 80-90% for intermediates, 85-95% for advanced)

2) Select the eccentric tempo (something like 1-3 seconds for strength, 3-5 seconds for functional hypertrophy, 4-6 seconds for total hypertrophy)

3) The concentric portion is ALWAYS performed as fast as possible. Obviously if the external load is heavy OR as fatigue sets in during the set, the actual speed of the bar will decrease. But the intent to lift it fast remains

4) Select the number of sets

So I believe that TUT and TTUT is a "by-product" rather than a significant training parameter.


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on est dans le sujet avec ça ou non :

http://www.workout2.tonsite.biz/phpBB2/news.php?action=detail&article=24&sid=18eb8469c1aa4fa27b1f5d6cb580dbf7

Il s'agit d'une traduction d'un article de Chad Waterbury. Lui semble contre cette durée de 40 à 70 secondes pour recruter correctement et complétement ses fibres musculaires.

c'est pour cela que j'ai mis ce lien, avis divergent (mais je ne savais pas s'il traitait exactement de la même chose)

Voici un autre extrait d'un document de Charles Poliquin concernant le temps sous tension et la façon de cycler :

Citation :

TRAINING FOR MASS PRINCIPLES

...

Principle 6: Alternate between volume and intensity as training stressors.
For most individuals, I find that alternating every 3 weeks cycles of high volume (accumulation phase) with 3 week cycles of high intensity. (intensification phase) works best . This type of training has had great success with my athletes. On average 16 to 18 lbs of lean body weight are gained over a 12 week period. Samples routines are provided in Part II of this chapter.

During an accumulation phase, for most individuals the loading parameters should look like this:

Reps: 8-20
Sets/exercise: 3-4
Rest intervals 60-90 seconds
Number of exercises/bodypart 2-3
Time under tension per set 40-60 seconds
Total sets per bodypart 6-8

During an intensification phase, for most individuals the loading parameters should look like this:

Reps: 5-8
Sets/exercise: 4-5
Rest intervals 3-4 minutes
Number of exercises/bodypart 1-2
Time under tension per set 30-40 seconds
Total sets per bodypart 8-10

I suggest you start off with a 3 weeks accumulation alternated with 3 weeks of intensification to get a base level concept. That usually for about 70% of trainees. After this, I suggest you experiment with the right ratio of volume and intensity that works for you.

You may find that 2 weeks of accumulation alternated with 3 weeks of
intensification works best for you because your tolerance for volume is limited. On the other hand, your cousin may find that 3 weeks of accumulation alternated with 2 weeks of intensification works best for him. There is no best ratio, only the one that works best for you. The 2% rule as explained in principle 3 will help you determine how long you should stay on a particular program.

...

Principle 8: In accumulation phases, load the muscles for at least 40 seconds per set.
To gain size the muscles need to be loaded long enough. Of course, there are genetic freaks who can gain with sets of only 5 to 10 seconds duration, but they are the exception not the rule, and they don’t even need to read this chapter anyway. Powerlifting champion Roger Estep comes to mind in this matter, he had a better physique than most Mr. America contestants, yet his preferred rep/set scheme was multiple sets of one rep.

So for example, lets say you take 5 seconds to complete the eccentric portion of the lift, and 1 second to complete the concentric range, your repetition cycle is of 6 seconds on average, therefore you want to do minimum of 7 reps per set if you are following that tempo prescription.

When people fail to make gains, it is often because they rush through sets. If one were to ask me what is the ideal time under tension to gain size, I would say 40seconds, this will work in about 60% of individuals. For individuals with high fasttwitch make-up, this value is around 20 to 30 seconds. On the other hand, about 20% of individuals get better hypertrophy response from doing sets in the range of 60 to 70 seconds per set.

Principle 9: In intensification phases, load the muscles for at least 20 seconds per set.
In this phase, your goal is tap in higher threshold motor units, therefore you will be using greater loads for less reps.

So for example, lets say in the bench press, you are taking 2 to complete the eccentric portion, taking a 2 second pause in the bottom position of the lift, and 1 second to complete the concentric range, your repetition cycle is of 5 seconds on average, therefore you want to do minimum of 4 reps per set if you are following that tempo prescription.

In intensification phases, pausing between reps permits greater motor unit
activation, thus the handling of greater loads. A pause as short as 2 seconds in the favorable angle of the range of motion is sufficient to greatly enhance activation of the muscle’s motor unit pool.