EXAM 2- Adaptations to Resistance Training

after 3-6 months of resistance training…

• 25-100% strength gain

• learn to more effectively produce force

• learn to produce true max movement

strength gains result from..

• increased muscle size

• altered neural control

strength gains can occur without

hypertrophy

strength gains cannot occur without

neural adaptations such as

• motor unit recruitment

• stimulation frequency

• synchronization

crossover effect

what you do on one side will help the other side

synchronous recruitment

motor units fire together, rather than at slightly different times

Neural drive

RT increases the number of motor units recruited to perform a maximal contraction

rate coding

RT may increase rate coding of motor units

autogenic inhibition

normal intrinsic mechanisms that inhibit muscle contraction if tendon tension is too high (golgi tendons)

how does RT impact autogenic inhibition

can decrease inhibitory impulses allowing the muscle to generate more force

how does the coactivation of agonists and antagonists lead to strength gains?

reduced coactivation may contribute minimally to strength gains

how does the morphology of neuromuscular junctions lead to strength gains?

increased PGC1-a

How does RT impact PGC1-a?

• increased branching of presynaptic neuron

• increased presynaptic vesicles containing ACh

• increased number of ACh receptors on cell membrane

transient hypertrophy

increased muscle size that develops after a single bout of exercise

chronic hypertrophy

increased muscle size that occurs with long term RT

what are satellite cells?

• assists with muscle recovery

• fuses to damaged muscle fibers

• are stem cells

• can turn into either actin or myosin

repeated bout effect

attenuated muscle damage with successive stimuli at the same intensity. Highlights the importance of progression

what happens when there is fiber hypertrophy?

• increase in size (cross sectional area)

• more myofibrils

• more actin/myosin

• more sarcoplasm, connective tissue

what happens to protein synthesis during exercise?

synthesis decreases and degradation increases

what happens to protein synthesis after exercise?

synthesis increases, degradation decreases

RT increases protein synthesis due to the release of anabolic hormones such as

• testosterone

• GH

• IGF-1

How does GH directly impact cellular growth?

GH released from the pituitary gland will directly travel to muscle tissue

How does GH indirectly impact cellular growth?

GH released from the pituitary gland will travel to the liver which will release IGF-1 and travel to the muscle tissue

what is myostatin-1 responsible for?

limits muscle growth ensuring that muscles do not grow too large

what muscle fiber types hypertrophy?

All muscle fiber types hypertrophy. Type 2 have greater hypertrophy than type 1

Hyperplasia

increase in the number of fibers within a muscle

type 2 become more _______ with aerobic training

oxidative

type 1 become more ________ with anaerobic training

anaerobic

How does diet impact protein synthesis?

eating more protein after resistance training can increase protein synthesis

when does protein synthesis occur?

• eating

• insulin

• exercise recovery

• exercise + eating

when does protein degradation occur?

• fasting

• during exercise

• disuse (aging)

• disease (cancer, HIV, etc)