BTEC National - Sport

Support for P4

BTEC National - Sport

Unit 1: Principles of Anatomy and Physiology in

Sport

Activity 13 – Born or built?

What do you reckon? Are top performers born that way or do they develop over a period of time?

Have a look at the following information and then make your decision!

Are you a better sprinter or distance runner? It is thought that having more fast and slow twitch muscle fibres may determine what sports athletes excel at and how they respond to training.

We therefore need to look into more detail at the type of muscle fibres. They can be broken down into two main types:

 slow twitch (or Type I) muscle fibres and

 fast twitch (Type 2) muscle fibres, which can be further categorised into Type

2a and Type 2b fibres.

To find out more about fibre types the following link is certainly useful:

Slow Twitch (Type I)

The slow twitch muscles are more efficient at using oxygen to generate more fuel for continuous, extended muscle contractions over a long time. Therefore, slow twitch fibres are great at helping athletes run events such as a marathon

Marathon runner – Paula Radcliffe

Fast Twitch (Type 2)

Because fast twitch fibres use anaerobic

metabolism to create fuel, they are much

better at generating short bursts of strength

or speed than slow muscles. However,

they fatigue more quickly. Therefore, slow

twitch fibres are great for helping sprinters.

100M Sprinter – Usain Bolt

Type 2a Fibres

These fast twitch muscle fibres are also known as

intermediate fast-twitch fibres. They can use both

aerobic and anaerobic metabolism almost equally

to create energy.

400m hurdler – Dai Greene

Type 2b Fibres

These fast twitch fibres use anaerobic metabolism to create energy and are the ‘classic’ fast twitch muscle fibres that excel at producing quick, powerful bursts of speed. Great for a high jumper!

High Jumper – Germaine Mason

On average, we have about 50% slow twitch and 50% fast twitch fibres in most of the muscles used for movement. An Olympic sprinter on the other hand tends to have 80 % fast twitch fibres!!

What are you?

Think about the sports that you excel in and decide what % type 1, type 2a

& type 2b muscle fibres you may have.

Explain your answer below…..as clearly as you can!

Having done that, can you put the each of the following statements into the correct column (in the table over the page)?