Muscle Fiber Ratio Test

muscle fibers

Let me remind you that muscles consist of of muscle fibers, which are subdivided into slow (red) and fast (white). You can read more about muscle fibers in the article Human Muscle Anatomy

If you know the ratio of muscle fibers, then you can accurately determine whether your body is predisposed to bodybuilding or if another sport is more suitable for you. Let me remind you that the more fast muscle fibers you have, the more results you can achieve in bodybuilding. But this does not mean that a person who is mainly dominated by slow (red) fibers will not be able to build large muscles. They can, just for such a person, this process will be a little more complicated.

One-repetition maximum test

determination of the repetition maximum

Well, to start doing the muscle fiber ratio test, you need to know your one-rep maximum. That is a weight that you can lift only once without breaking technique and excess stress. If you have been in the gym for a long time, then you probably already know your one-rep max in three basic exercises. If not, or if this article is read by a beginner, then this is done as follows:

1) The one-rep max test should be done on a non-workout day, or at least at the beginning of a workout.

2) Choose a basic exercise with which you will conduct the test, for example, the bench press.

3) Warm up well and warm up your muscles.

4) Hang a weight on the barbell that you can do at least 8 reps. Do the set with 6 reps.

5) Relax for 2-3 minutes.

6) Add 10-15% to the weight on the barbell and do 3-4 reps.

7) Relax for 2-3 minutes.

8) Add another 5-10% to the barbell and do 2-3 reps.

9) Rest 2-3 minutes more.

10) Continue adding weight on the barbell in the same way until you can only squeeze the barbell once. This will be your one-rep maximum. Remember to use the help of a partner when performing this test.

Muscle Fiber Ratio Test

comparison of muscle fiber ratio

Once you know your one-rep maximum, you can begin the muscle fiber ratio test. For example, consider it on the same exercise – bench press.

1) Set the barbell to 80% of your 1RM.

2) Lie on a bench and do the exercise for the maximum number of repetitions.


– If you do less than 8 repetitions, then you have much more fast muscle fibers than slow ones.

– If you do 8 to 12 repetitions, then the number of fast and slow fibers is approximately equal.

– If you do more than 12 repetitions, then slow muscle fibers predominate.

Let me remind you that the test I described was carried out on an exercise – bench press. We determined the ratio of muscle fibers in the muscles of the chest. If we carry out this test for the muscles of the legs, then the result may be completely opposite, since in different muscle groups there may be a different ratio of muscle fibers.

Video about determining the type of muscle fibers

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