Resistance exercise 3 2.0 Flashcards
Is muscle fibre hyperplasia the cause of muscle hypertrophy?
NO
What factor other than muscle size can influence how much force a muscle will produce?
Neural factors–> how much of the action potentials are actually getting to the muscle to cause it to contract
What does each motor neuron axon join up with?
Muscle fibres
How many muscle fibres per axon?
multiple
How many axons per muscle fibre?
1
What makes up a motor unit?
The spinal cord, the motor neuron axon and the muscle fibres
How is motor unit size measured?
Fibres per unit
How many fibres per motor unit are there in the eye?
10 bc fine motor control is needed
How many fibres per motor unit are there in the hand?
300
How many fibres per motor unit are there in the gastrocnemius?
2000
What needs to happen for neuromuscular co-ordinaiton?
Agonist muscle must be maximally switched on at the right time, Support from appropriate synergistic ans stabiliser muscles, opposed by minimal antagonist activation
What can be increased regarding the motor unit to generate more force?
Motor unit firing frequency
How does resistance exercise affect motor units positively?
It allows us to increase firing frequency
Two types of motor units?
Type 1 and type 2
Type 1 motor unit?
Smaller, easier to switch on, less force
Type 2 motor unit?
Larger, harder to switch on, more force
What do type 2 fibres need to happen before they are recruited?
Type 1 fibres to be recruited, and a higher threshold of excitation than type 1
Use of type 1 fibres?
Lifting something light, clicking a button etc
How does resistance training positively impact the recruitment of motor units?
Reduces the electrical excitatory threshold required to switch on the type II motor units
What kind of runners have a higher proportion of type 1 muscle fibres?
Distance runners
Does weight load have an effect on muscle growth?
Sort of (maybe higher load better) but not 100% sure
What effect does exercise have on anabolic hormomes?
It increases the concentration of them
Examples of anabolic hormones?
insulin, growth hormone, testosterone
What happens to strength as a result of blocking testosterone?
Loss in strength
Why does leg press increase concentration of anabolic hormomes?
The muscles surrounding the gonads will spike testosterone and anabolic hormones if exercised
