Forums SuperPhysique

les études montrent que le lourd ~5 reps développent aussi bien sinon mieux les fibres lentes que du 20-30 ou 10-12.

The exercises were performed in the fixed order of leg press, squat, and knee extension. After warming up:

· The Low-Rep group used their 3-5RM for four sets with 3 min rest between sets and exercises.

· The Intermediate-Rep group used their 9-11RM for three sets with 2 min rest.

· The High-Rep group used their 20-28 RM for two sets with 1 min rest.

During the study, the resistance was progressively increased as subjects were able to perform more reps in order to ensure subjects were always using their true RM for each rep range.

So what happened? Did the type-I fibers increase most in the high-rep group? Did only the type-II fibers hypertrophy in the low rep group? If you believe you must do high reps for type-I fibers to grow and low reps for type-II fibers to grow then that’s exactly what should have happened!

On the other hand, if hypertrophy is a matter of load, and all fibers hypertrophy in response to increasing load, then hypertrophy should go up as load goes up. In other words the group that lifted the heaviest relative weight should have experienced the greatest amount of hypertrophy in ALL fiber types irrespective of the number of reps (within reason). And that is exactly what happened.

Here is a breakdown of the hypertrophy caused by each rep range. [Remember, each group trained to failure regardless of RM used so muscular fatigue was equal between groups.]

High-Rep (20-28RM)
Type-I
· pre = 3894 post = 4297 (10.3% increase)
Type-IIA
· pre = 5217 post = 5633 (8.0% increase)
Type-IIB
· pre = 4564 post = 5181 (13.5% increase)

Med-Rep (9-11RM)
Type-I
· pre = 4155 post = 4701 (13.1% increase)
Type-IIA
· pre = 5238 post = 6090 (16.3% increase)
Type-IIB
· pre = 4556 post = 5798 (27.3% increase)

Low-Rep (3-5RM)
Type-I
· pre = 4869 post = 5475 (12.4% increase)
Type-IIA
· pre = 5615 post = 6903 (22.9% increase)
Type-IIB
· pre = 4926 post = 6171 (25.3% increase)

Les fibres IIb, il n'y en n'a pas chez l'homme (ce sont des IIx) icon_biggrin.gif

Numerous studies have shown that high resistance, low repetition exercises are more effective than low resistance, high repetition exercises in promoting muscle hypertrophy

Weight training studies and empirical observations of athletes have reinforced the importance of generating muscular tension. It must be developed at an adequate intensity and duration for the optimal development of strength. The majority of studies have found that the ideal number of repetitions are between four and eight (repetitions maximum, 4-8 RM). They should be practiced in multiple sets (3 or more). Strength gains are less when either fewer or greater numbers of repetitions are used. These findings are consistent with the progressive resistance training practices of athletes.

Body builders usually do more sets and repetitions of exercises and more exercises per body part than weight lifters or strength athletes. Their goal is to build large, defined, symmetrical muscles. It is not known if typical body building training method is the most effective means of achieving their goals. Numerous studies have shown that high resistance, low repetition exercises are more effective than low resistance, high repetition exercises in promoting muscle hypertrophy.

Results: At the mid-point of the training, the HF group had 50% greater gains in isometric strength, although this was not significant (4.5 weeks: HF, 13.3 (4.4)%; LF, 8.9 (3.6)%). This rate of increase was not sustained by the HF group, and after nine weeks of training all the strength measurements showed similar improvements for both groups (isometric strength: HF, 18.2 (3.9)%; LF, 14.5 (4.0)%). The strength gains were limited to the longer muscle lengths despite training over the full range of movement.

ideal number of repetitions are between four and eight

For example tests have compared fiber recruition in athletes when they lifted in the 5-15 second range, to the 30-70 second range and found that the latter incorporated much more muscle fibers than the former. The reason why this is true is because at a lower second range your muscles would fail due to a rapid atp( our bodies main energy source ) shortage, and this rapid shortage of energy, just doesn't allow enough time for your muscles to be stimulated enough to grow. Essentially, the total time that the muscle fibers are required to produce force is shorter in low-rep sets than in higher-rep sets. Simply put, a hard set that lasts 30-70 seconds delivers more growth stimulus to the muscle cells than a hard set that lasts below this because in a shorter set, failure may occur due to reasons other than muscle fiber fatigue and before a significant growth stimulus has been achieved. This should give you a clearer understanding of why bodybuilders tend to lift in a higher rep range than power lifters.

Simply put, a hard set that lasts 30-70 seconds delivers more growth stimulus to the muscle cells than a hard set that lasts below this

Body a écrit:Les études sur le nombre de rep, quelles conneries ! Sachant que nous n'avons pas les mêmes capacités nerveuses, le nombre de rep "idéal" ( le moins mauvais ) est individuel. Ce qui compte, c'est de trouver celui qui permet d'avoir le moins d'inhibition nerveuse tout en ayant une charge relativement lourde, qui quand ca devient dur permet d'arracher qq rep et ne coupe pas d'un coup !!

Body a écrit:Il faut regarder dans les anciens MDM vers le numéro 210 a peu près.