Muscle Building Net

There are two types of muscle fibres:

1. slow twitch fibres
These muscle fibres are slow and have so-called “endurance power”. Because of this the body uses these muscle fibres in sports where an activity takes place over a longer period. These muscles work aerobic. That means, oxygen is used to generate power.

2. fast twitch fibres
These muscle fibres are fast twitching, they don’t have endurance power. They can build up a big tension: therefore these muscles are primarily used in strength training. They work an-aerobic and can be used for a maximum of 2 minutes.

Which kind of fibres you have the most in your body is determined genetically. Endurance power athletes have a lot of (up to 80%) slow twitch fibres – strength training athletes have more fast twitch fibres. This is the real genetic difference. But it is not as extreme as you might think.

You can divide fast twitch fibres into subgroups.

From type 1 and type 2, different genetic compositions are possible.