1. What are the three types of muscle fibers?
Neuromuscular Function
Muscle Fiber Types
What are the three types of muscle fibers?
Briefly describe each
Fiber type
Slow Twitch (Type I)
Fast twitch A
(Type IIA)
Fast twitch B
(Type IIB)
Contraction time
slow
fast
Very fast
Fatigue resistance
high
intermediate
Low
Used for:
Aerobic activity
Long term anaerobic
Short term anaerobic
Capillary density
High
Intermediate
Mitochondria density

2. Neuromuscular Function
Recruitment of muscle fibers
Recruitment order of voluntary isometric & concentric contractions**
Type I type IIA type IIB
(Slow) (intermediate) (fast)
**No matter the type of exercise muscle always recruit this way

3. Neuromuscular Function
Recruitment of muscle fibers
Changing the recruitment pattern of muscle fibers
Eccentric muscle contractions (muscle lengthening) can change the recruitment pattern.
Fast twitch can be recruited first, then the slow twitch if the speed of the exercise is moderate to fast.

4. Neuromuscular Function
Training specific muscle fiber types
How can we train our bodies to become better at certain activities?
What an athlete is born with is what he
or she must live with.
You cannot increase the number of a specific fiber type but you can hypertrophy a specific type of fiber through specific training , thus increasing the volume of that specific fiber type.

5. Neuromuscular Function
Muscle fiber composistion
How do we determine our muscle fiber type?
Muscle biopsy (best method)
Testing an athletes muscle groups for different muscle fiber properties. (chart from question 1)
Example:
establish a 1RM of any exercise.
lift 80% of 1RM as many times as possible.
7 or less reps most likely more than 50%FT fibers
12 or more reps most likely more than 50% ST fibers

6. Neuromuscular Function
Training specific muscle fiber types
Training recommendations:
Increase neuromuscular component of maximum strength:
95% of 1RM, 1-3 rep range.
Increasing maximum strength by stimulating muscle hypertrophy:
80% of 1RM, 5-8 rep range.
Increasing muscle size with moderate strength gains:
% 1RM will vary, 6-12 rep range.