Resistance exercise 2 2.0 Flashcards
What happens as a result of a new ATP binding to the myosin head?
The head is released from the actin binding site
What happens if there is still calcium left in the cell once the myosin head has released?
The myosin head will attach to the next nearest actin filament binding site
What happens if there is no Ca2+ or ATP?
The process stops
What is hypertrophy?
Net muscle gain
What is atrophy?
Net muscle loss
What happens to muscle synthesis when amino acids are ingested?
The rate of muscle synthesis increases
What happens to the rate of muscle breakdown when AAs are ingested?
decreases
What happens to the rate of muscle synthesis a while after AA ingestion w/o exercise?
Decreases
What happens to the rate of muscle breakdown a while after AA ingestion?
Increases/ returns to original level
What happens to muscle breakdown if you do exercise a while after eating?
It increases higher than it would do if you hadn’t done exercise
What happens to muscle synthesis if you do exercise after eating?
It increases a lot
How does muscle synthesis increase after doing exercise?
The anabolic response is primed as a result of doing resistance exercise
How long is the anabolic response primed post exercise?
24-48 hrs
What happens to hypertrophy after the onset of training?
It is delayed
Why is hypertrophy delayed after training?
A lot of the muscle protein synthesis is repairing the muscles that were damaged as a result of the training, so it isnt “new” muscle
What happens to muscle synthesis as you train more?
There is less muscle damage, so more of the muscle synthesis is going to hypertrophy instead of repair
Why do muscles look larger after training even though they have been damaged?
Oedema induced muscle swelling
What is Oedema induced muscle swelling?
A swelling in response to the muscles being damaged
What happens as a result of Oedema induced muscle swelling?
The muscle size/cross sectional area is artificially increased
Why does hypertrophy slowly plateau as you train more?
The “priming effect” loses its potency so less hypertrophy occurs
What did the Damas 2017 study show about trained muscle hypertrophy effect in response to damage compared to non-trained muscle?
The initial increase in hypertrophy immediately post training for the trained muscle was the same as the untrained muscle (“priming effect”) however it dropped off over time a lot faster than the untrained muscle did
What is muscle fibre hypertrophy?
The muscle cells getting bigger
What is muscle fibre hyperplasia?
The amount of cells increasing
What increases post resistance training?
Fibre hypertrophy
How does myofiber hypertrophy happen?
myofibril splitting
What is a myofibril?
An organelle in a muscle cell
Role of myofibril?
produce contraction
Why is it a challenge to measure hyperplasia
Would have to chop leg in half, count number of cells, do exercise, chop leg in half and count cells again
When does hyperplasia definitely occur?
In utero (when foetus is growing)
At what point in utero does myofiber hyperplasia stop?
24 weeks (60-70% of mammalian gestation)
