Muscle fiber type

# Which muscle fiber type do you have? Muscle fibers are the basic structures of the musculature and can be roughly divided into muscle fiber types 1 and 2. This division is based on various properties of the muscle fibers, such as contraction speed, fatigue resistance and energy source. # Muscle fiber type 1 Type 1 muscle fibres are so-called slow-twitch fibres and specialize in prolonged endurance exercise. They are equipped with a high number of mitochondria and use both glucose and fatty acids (fat burning) to generate energy, for which they require sufficient oxygen (aerobic). These muscle fibers are suitable for sports over a longer period of time, but with low to medium intensity. Examples include endurance sports such as long-distance cycling, marathon running, swimming, dancing, etc. # Type 2 muscle fibers Type 2 muscle fibres are fast-twitch fibres and are specialized for explosive, powerful movements. They show a faster contraction speed, but are fatigued more quickly. In order to be able to perform high-speed strength, they use readily available glucose and burn it without oxygen (anaerobically). This makes them interesting for speed and strength sports with their short-term but intensive movements such as sprinting, weightlifting, crossfit, etc. > ## Good to know > > The composition of the muscle fibers in the muscles is genetically determined, but can be influenced by consistent training. Training can change the ratio between type 1 and type 2 muscle fibers in one direction or the other. > Repeated and consistent endurance training improves the type 1 muscle fibers, while repeated and consistent strength training causes the type 2 muscle fibers to hypertrophy and the muscle gains in size and strength. # Are your sport type and your muscle fiber type contradictory? It may be confusing at first glance if your sport type (strength/endurance) and your muscle fiber type (Тур 1/Type2) seem to give contradictory results. At second glance, this result can open up worlds. With this result, your potential lies in both strength training and endurance. This makes training (frequency, intensity, regeneration...), nutrition (glycogen stores, fat burning...) and their enthusiasm for certain sports more important. An example of how epigenetics (lifestyle and life circumstances) and your genetic potential can never be considered separately. Good luck setting new goals! # What do genetics have to do with it? We examine a gene with regard to your muscle fiber type: The ACTN3 gene (alpha-actinin 3 gene) carries the blueprint in cells for the protein of the same name, alpha-actinin-3, which plays a central role in regulating muscle fiber types and their muscular contraction and performance. Variations in the gene influence the production of alpha-actinin-3 in skeletal muscles with the following effects: - Variation rs1815739 of the ACTN3 gene: genotypes C/C and T/C produce sufficient alpha-actinin-3 in their muscle fibers. This correlates with improved muscular contractility, especially in fast and explosive sports. - Variation rs1815739 of the ACTN3 gene: The T/T genotype produces little to no alpha-actinin-3 protein. This results in a limited ability for high-speed strength sports and longer regeneration phases after sport. This does not necessarily mean that you are less athletic, as other epigenetic factors such as training, diet and environment also play an important role.