1. Muscles Types of muscle fibre. Muscle fibres & Sport.
How muscles work in pairs.

2. 10 1 9 2 8 3 7 4 6 5

3. Deltoid
Trapezius
Biceps
Triceps
Latissimus Dorsi
Gluteals
Abdominals
Hamstrings
Quadriceps
Gastrocnemius

4. Types of Muscle Fibre
There are two different types of muscle fibre which can be found in muscles.
Fast twitch fibres.
Slow twitch fibres.
Fast Twitch Fibres
These contract faster than slow twitch fibres & with much more force. They are used whenever rapid, powerful movements are needed. They do not have a good supply of oxygen, so they tire very quickly. They are suited to activities that need bursts of strength & power such as sprinting & weightlifting.

5. Slow Twitch Fibres
These work for long periods of time because they have a good supply of oxygen. Slow twitch fibres are not as big or as strong as fast twitch fibres, & they also take longer to contract. They are most suited to activities that need endurance such as long-distance running & cycling.

6. Every muscle contains a mixture of these different fibres.
For example, in the gastrocnemius, there is a high percentage of fast twitch muscles.
Athletes will have a different mix of fast & slow twitch fibres depending on the sport they play. Distance runners have about 80% slow twitch fibres while some weight lifters have 80% fast twitch fibres.

7. Fast or Slow Twitch?

8. Fast or Slow Twitch?

9. Fast or Slow Twitch?

10. Fast or Slow Twitch?

11. Fast or Slow Twitch?

12. activity average % ST range of % ST
marathon
cross country skiers
cyclists
800m runners
untrained
shot putters
sprinters
The table above shows the average % & range of slow twitch muscle fibres in sports performers. Use the data to explain the differences in muscle fibre relevant to the events they perform.

13. How Muscles Work