The different types of muscle fiber: The secret of real athleticism

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What do we actually mean when we talk about “athleticism”?

Your physical appearance will actually depend on the specific muscles that are strengthened. Every athlete therefore develops a physique that is typical for that specific sport. It can therefore seem strange that long distance runners, for example, have a rather wiry physique yet sprinters are very muscular, even though the movement and thus the muscle groups they train are very similar. The secret therefore lies not in the movement itself, but in the intensity and duration itself. This is where the different types of muscle fiber come into play.

The ideal types – slow and fast twitch fibers

You already know the classification of smooth, striated and cardiac muscle and how a skeletal muscle is built structurally. Inside of each muscle, we find the muscle cells: a distinction is made between fast and slow twitch muscle fibers, as well as various intermediate and mixed types.

In this article we will briefly introduce you to the basics of these muscle types, what advantages and disadvantages they each have and why this is important for Free Athletes.

Slow Twitch – non stop in use

Slow twitch fibers are also known as red fibers since they have a high oxygen content. In order to store oxygen in muscle cells the oxygen transporter myoglobin is needed. As this protein has a red colour, the muscle fibers appear also reddish. They mainly obtain their energy from glycogen and fat by using oxygen: when oxygen is used, we talk about aerobic energy generation. However, since this type of energy supply is a lengthy and complicated process, these fiber types are not able to contract quickly and therefore are less integrated in rapid powerful movements. The advantage is that this type of fiber has a high tolerance against fatigue. Since fatigue is one of the prerequisites for muscle growth, these fiber types are only partially assessed for hypertrophy. Red muscle fibers are almost constantly in use. Without them, we would not even be able to perform the most basic natural movements such as sitting, standing or walking.

This is precisely why – for your everyday health – they should not be neglected and should be trained with endurance activities such as longer runs. Otherwise you may risk poor posture and imbalance which can result in various complaints such as back pain.

Fast-twitch fIbers – the muscle makers

Fast twitch fibers have a lower myoglobin and therefore lower oxygen content, which is why they do not appear reddish but rather bright. So they are also known as white muscle fibers. In contrast to the red fibers, they gain their energy anaerobically, which means without oxygen and mainly from the sugar glycogen. Glycogen can provide energy very quickly and in the short term, so the white fibers are able to contract faster and stronger. As fast as the energy is provided, that fast she is – unfortunately – exhausted. White muscle fibers are the first to fatigue, which is why they are the last to be activated by the body.

The good news: white muscle fibers are thicker and have a bigger potential to grow. Although training of fast powerful movements does not change the amount of white muscle fibers, it changes their size and thus their mass fraction in the muscle, letting the muscle grow.

Intermediate fibers – the allrounder

There is also a third fiber type: the intermediate muscle fibers. Depending on which aspect you look at (energy supply, color, power potential and contraction speed), there are also various subtypes. They are very adaptable – both in the short and long term.

We find all kinds of fiber types in each muscle. Depending on how and how often the muscle is stressed, its internal composition is different from others. Although it is believed that the distribution of the different fiber types is determined genetically, research has observed repeatedly, that it is possible to transform this distribution through specific training. Here, the intermediate fiber types are particularly interesting. They can be influenced and manipulated to work well in any direction. Also, a conversion of white into red muscle fibers is observed.

That is the reason why the appearance of endurance runners and sprinters is so different, although the movements they perform are similar. The muscle fibers are the secret, why athletes can look so different – depending on the sports they do. Sprinters need to perform fast and powerful movements, so many white muscle fibers are activated, while endurance runners train the kinds of muscles which have a high endurance level.

But, what do we mean by athleticism?

An athlete develops comprehensive athletic ability. Speed, mobility, strength and enduranceFreeletics Bodyweight, Running, and Gym complement each other perfectly, ensuring an athletic body.

Freeletics Bodyweight requires mainly white and intermediate muscle fibers, since it is necessary to release power at high speed over a certain period. For example, to lift off the ground, when doing a burpee. Medium and long distance runs, that will be part of your training with Freeletics Running for example, tone red muscle fibers and optimize the energy supply of the whole body. With the combination of endurance and fast forceful movements you can develop important skills: your muscles are more flexible overall, more versatile, more adaptable.

That’s what we mean by athleticism. An athlete is able to master both; distances and exertion over a medium or long period of time, as well as a very quick release of his potential. These two capabilities and their associated training methods complement each other perfectly. A muscle that is strong and durable at the same time is synonymous with increased athletic ability.

This is also shown in your outer appearance: The combination of Bodyweight, Running and Gym training challenges your muscles in different ways and builds them as nature intended. An athlete does not have unnatural bulky muscles, nor is he thin or gaunt. An athletic look is characterized by natural, toned, aesthetic muscles. The posture is upright, the walk confident and body-conscious. Therefore, don’t be deterred by running sessions even if you want to gain muscles. By now you know: You also need them to gain muscles!