FAST & SLOW TWITCH MUSCLE FIBRES Year 11 P.E

How muscles respond to training and physical activity… each fiber type is unique in its ability to contract in a certain way. Human muscles contain a genetically determined mixture of both slow and fast fiber types. On average, we have about 50 percent slow twitch and 50 percent fast twitch fibers in most of the muscles used for movement.

WHAT’S THE DIFFERENCE?

SLOW TWITCH

Red fibres – best suited to aerobic, endurance work. Eg. Triathlon (Type 1 fibres)

Contract slowly (perform over

long periods, low force)

FAST TWITCH

White fibres – best suited to short-duration, high intensity anaerobic work. Eg. Sprinting (Type II fibres)

• Produce larger force, tire more rapidly

FAST TWITCH TYPE A & B P. 24 Type A : Partially aerobic Type B: Purely anaerobic

TESTING YOUR MUSCLE FIBRE MAKE-UP Muscle Biopsy (removal of a sample of tissue for lab

examination)

REVISION!!! SAC - MONDAY Create your own revision PP covering all of the relevant

information (use pictures of yourself completing movement wherever possible)

THINKING THINGS THROUGH P. 26 Complete Qu’s 3 & 4