Muscle Fibre Types Flashcards
What are the two types of muscle fibres
Slow twitch
Fast twitch
Name all 3 muscle fibres and list what energy system them would be used in
Slow twitch type 1- aerobic system
Fast twitch type 2a- anerobic glycolytic system
Fast twitch type 2b- ATP-PC system
What two factors depend on which fast twitch fibre is used ?
The intensity and duration of exercise
What do i need to know about the muscle fibres for the exam ?
Both the structural and functional characteristics each muscle fibre type
What do i need to explain when asked about muscle fibres types ?
HOW and WHY these characteristics make them suitable for activity
What functions do the slow twitch muscles fibres have
High aerobic capacity
High fatigue resistance
Slow speed and force of contraction
Low anerobic capacity
Used long distance activity and events
What functional characteristics do fast twitch type 2a muscle fibres have ?
Fast speed of contraction
High speed of contraction
Moderate/high anaerobic capacity
Low/moderate aerobic capacity
What is another name for name for the fast twitch type 2a muscle fibre ?
Hybrid fibre- this is because it can be used for both anaerobic and aerobic exercise
What are some functional characteristics of the fast twitch type 2b fibre ?
Low fatigue resistance
Very high anaerobic capacity
Very fast speed of contraction(fastest out of the 3)
Very high force of contraction(fastest out of the 3)
Intended for maximal intensity exercise e.g sprints
List all the structural characteristics of the slow twitch type 1 muscle fibre type ?
Small fibre size
Large capillary count
Large mitochondria count
Large myoglobin stores
Low anaerobic stores(pc+glycogen)
List all the structural characteristics of fast twitch type 2a muscle fibre
Large fibre size
Moderate amount of capillaries
Moderate amount of mitochondria
High anaerobic stores(pc + glycogen)
Moderate myoglobin stores
List all structural characteristics of fast twitch type 2b muscle fibre.
Large fibre size
Small Capillary count
Small mitochondria count
Low myoglobin stores
Highest anerobic stores out of the 3 (pc and glycogen)
Which fibre type has the largest motor unit size
Fast twitch Type 2x
Fast twitch Type 2b has intermediate
Slow twitch Type 1 has the lowest
Can fast twitch type 2a muscle fibres be converted into fast twitch type 2b muscle fibres ?
Yes
What must i do if this comes up in the exam
Describe physical demand of the event
Must refer to characteristic of muscle fibres(structural and functional)
Explain how the structure or function impacts performance
Link to energy systems
What are other names for all 3 muscle fibres types ?
Fast twitch type 2b- fast glycolytic
Fast twitch type 2a- oxidative glycolytic
Slow twitch type 1- oxidative
