Author: Akhmetova Aigerim
Editor: Merentsova Anastasia
As you know, humans have two types of muscle fibers: fast and slow.
Slow fibers have a slow rate of contraction. They are maximally adapted to perform continuous continuous work. These fibers are called red because of their color. They are surrounded by a network of capillaries that constantly deliver oxygen. White muscle fibers are capable of high-intensity, hard, but short-term work. It is assumed that the white type of muscle fibers predominates in bodybuilders.
The study involved 12 people, including 6 bodybuilders and 6 physically untrained people. The area and maximum voluntary contraction of the quadriceps femoris muscle, as well as the architectonics of the vastus lateral muscle, were determined. In addition, a biopsy (intravital collection of cells for diagnostic purposes) of the muscles was performed and individual fibers were analyzed.
According to the results obtained, in the control group of bodybuilders, the cross-sectional area of the muscle fiber and their voluntary contractions were 32% higher. On sections of biopsy samples, the number of fast fibers of subtype 2A was 24% more than in the group of less trained people.
The results obtained indicate that it makes no sense to engage in strength training in order to improve endurance, since the red (slow) muscle fibers responsible for endurance develop during prolonged monotonous work that does not require explosive efforts.
Source: https://pubmed.ncbi.nlm.nih.gov/32921001/
