Fibre categories

Question 1

Fast twitch 2a

Structure

Answer 1

• Red-Pink colour.
• Large number of 
capillaries.
• Higher number of 
mitochondria cells.
• Diameter is larger than 
Slow Twitch, but 
smaller than Fast Twitch 
2b.
• Higher myoglobin 
content.

Question 2

Fast twitch 2a

Function

Answer 2

Type 2a can adaptively change its function depending on the type of
training that is being performed & the demand the fibre is being put under

Question 3

Fast twitch 2b

Structure

Answer 3

● Pale & white in colour.
● Fewer capillaries.
● Fewer mitochondria.
● Diameter is the 
largest.
● Lower myoglobin

Question 4

Fast twitch 2b

Function

Answer 4

● Oxygen delivery/consumption is less needed.

● Higher levels of force produced.

● Short-term contractions produced.

● Lower fatigue resistance.

● Functions anaerobically (without oxygen)

Question 5

Slow twitch

Structure

Answer 5

● Red in colour.

● Large amount of Capillaries.

● Higher number of Mitochondria cells.

● Diameter is the smallest.

● Higher myoglobin content.

Question 6

Slow twitch

Function

Answer 6

● Delivery & consumption of Oxygen is higher.

● Produces lower level of force.

● Long-term contractions produced.

● Resistance to fatigue is much higher.

● Aerobically functioned.(with oxygen)