Muscle fibre types Flashcards
1
Q
What are the three types of muscle fibres?
A
- Type I (slow twitch)
- Type IIa (fast twitch)
- Type IIb (fast twitch)
2
Q
List 6 characteristics of type IIa muscle fibres.
A
- Fast contraction speed - used for speed endurance-based activities.
- Moderate force of contraction.
- Generate greater force and more powerful contractions as they are larger than red fibres.
- Possess some aerobic characteristics such as moderate levels of myoglobin, mitochondria and blood capillaries.
- Fatigue resistant but not as much as slow twitch fibres.
- Stimulated by large motor neurons and are stimulated at a moderate frequency.
3
Q
List 6 characteristics of type IIb muscle fibres.
A
- Rapid contraction speed - used for speed, strength and power-based activities.
- High force of contraction.
- Fatigue very quickly - no oxygen.
- Generate greater force and more powerful contracting as they are larger than red fibres.
- Possess very few aerobic characteristics such as low levels of myoglobin, mitochondria and blood capillaries, but very high anaerobic characteristics such as high levels of glycogen.
- Stimulated by very large motor neurons and are stimulated at a very high frequency.
4
Q
List 6 characteristics of type I muscle fibres.
A
- slow contraction speed - used for endurance activities.
- Low force of contraction.
- Fatigue resistant.
- Contract repeatedly for continuous activity.
- Posses more aerobic characteristics such as high myoglobin, mitochondria and blood capillaries.
- Stimulated by small motor neurons and are stimulated at a low frequency.
5
Q
What are 2 examples of sports using type IIa muscle fibres?
A
- 200 metres.
- 400 metres. (up to 70% fast twitch)
6
Q
What are 4 examples of sports using type IIb muscle fibres?
A
- 100 metres.
- High jumper.
- Long jumper.
- Shotput thrower. (up to 80% fast twitch)
7
Q
What are 3 examples of sports using type I muscle fibres?
A
- Marathon runner
- Endurance swimmer.
- Cycylist. (up to 80% slow twitch)
