Muscle fibers and training – what you need to know

The human body has about 650 muscles. Unfortunately, it cannot be said precisely. Some muscles merge into each other, and some are no longer found in old age. But one thing is sure: the muscle fibers of the skeletal muscles enable us to move. So it might be a good idea to get to know about them and their function better. Read more about muscles fibers and training.

We have three different muscle types

We do not know exactly how many muscles we have, but we know how many muscle types we have. There are three: the heart muscles, the smooth muscles in the organs, and the skeletal muscles. The skeletal muscles are the only ones we can control by our will. Muscles such as the biceps or the thigh muscle consist of a bundle of elongated cells that make up the muscle fibers. Connective tissue holds these muscle fibers together. They are skinny but can reach a length of up to 12 inches.

Muscle contraction with actin and myosin

Inside these muscle bundles lies the secret of movement: the protein bundles known as myofibrils. They consist of the parallel subunits actin and myosin. When they shift against each other, the muscle shortens and develops its strength.

There are three different types of muscle fibers

Depending on the genes and the training condition, the fibers react at different speeds. On the one hand, there are the slowly reacting muscle fibers, called type 1. Good endurance athletes have a high proportion of them. Sprinters, on the other hand, have an above-average proportion of type 2 myosin fibers. For most people, the ratio of the two muscle fiber types is approximately balanced.

Muscle fibres can be changed by training

For a long time, scientists assumed that the proportion of muscle fibers was genetically fixed. But that is outdated. By appropriate training programs or electrostimulation, it is possible to change the balance a little. A change is also caused by aging processes. The slow muscle fibers dominate more and more in the aging muscle. This process can be stopped by training, but there are also limits to this at some point. But muscle growth works into old age. The adaptation symptoms take a little more time, but even 80-year-olds can still effectively train their muscles.

Slight muscle soreness is not so bad at all

The best indication of muscle growth through training is muscle soreness. This leads to micro-injuries in the muscle fibers. The body reacts immediately and activates so-called satellite cells. They form new protein structures and thus ensure that the muscle adapts and grows. But be careful: only a slight soreness of the muscles with a bit of pain or stiffness is recommended. If you overdo it, you can expect a compulsory break of several days.

Inactivity let shrink the muscles

If you do not train regularly or reduce your physical activity, your muscles and strength decrease. And unfortunately, at an alarmingly fast speed. What you have built up in a year may have almost completely disappeared after four weeks of inactivity. Regular training is therefore essential.