L9 Muscle strength Training: Neurophysical changes Flashcards
List the neural adaptation that occur with resistance training that increase muscular strength:
- greater efficiency in neural recruitment patterns
- Increased motor neuron excitability
- Increases CNS activation
- Increased firing rates and motor unit synchronicity
- Lowering of neural inhibitory reflexes
- Potentiation of reflexes in some muscles
- Inhibition of golgi tendon organs
Give a brief explanation of experimental evidence that support neural adaptation to strength training
in a study of strength training, the results showed an improvement in lifting the weight but holding a static force showed a lot less improvement. if the muscle had hypertrophied, you should get the same % increase in both tasks, therefore indicates neural changes.
Increases in strength but no increases in size
Explain the classic tri-phase EMG pattern seen in fast dynamic movements.
- Agonist activation moves limb.
- Antagonist provides braking force
- Agonist fine tunes the movement.
Agonist line above antagonist on the EMG. Both begin as a straight line. Big inverted U curve for agonist, then same for antagonist, then a second smaller agonist inverted U
Explain how change in firing rate and pattern can alter force output from a motor unit
you need a high firing rate to generate a fast movement.
The rate at which a muscle will increase to its max tension will be quicker with the higher stimulus frequencies
Trained athletes can maintain a higher firing rate of motor units and therefore peak forces for longer than an untrained individual.
Describe the relative contribution of hypertrophic and neural changes to strength gain in the first 8-10 weeks of strength training
Neural contribution decreases from about an 87% contribution to only about 10% contribution after 8 weeks of training. Hypertrophy on the other hand contributes to about 10% of the strength gain at the beginning, which then increases to about 85% after 8 weeks
