Fast-twitch muscle favours anaerobic metabolism: these fibres rely less on oxygen supply for their energy, and contain few mitochondria.

They are used in fast, short-term activities like sprinting, although they are also important in 'stop-and-go' activities such as football or basketball.

They are greater in size then slow-twitch muscle fibres and due to their less generous supply of capillaries are white or pale in colour.