CH 10 - Adaptations to Resistance Training Flashcards
resistance training
gains in muscular fitness
- after 3-6 months of resistance training:*
- > 25-100% more strength gain
- > learn to more efficiently produce force
- > learn to produce true maximal movement
strength gains in different individuals
young men experience the greatest absolute gains vs young women, older men, and children, due to incredible muscle plasticity
hypertrophy vs atrophy
increased muscle size (hypertrophy) - > increased muscle gain
decreased muscle size (atrophy) - > decreased muscle strength
association is more complex than that
strength gains result from _________
- > increases in muscle size
- > altered neural control
why is neural control important for strength gains
strength gains cannot occur without neural adaptations via plasticity
- > motor unit recruitment, frequency of motor nerve firing rates, better synchronization of motor units during a particular movement, and other neural factors are important to strength gains
explain the synchronization and recruitment of additional (through gains) motor units
- > motor units are generally recruited asynchronously (not all at the same time) but become more synchronis as strength is gained through endurance training
- > this is caused due to changes in the connections between motor neurons
- > this increased synchonicity means greater number of motor units are firing all at once, facilitating contraction and the increasing the muscles ability to create force
- >
autogenic inhibition
inhibitory mechanisms in the neuromuscular system that prevent the muscle from exerting more force than the bones and connective tissues can tolerate (i.e. golgi tendon organs)
- > training can decrease impulses from these mechanisms
- > stimulates the contraction of the agonist/antagonist muscle to prevent further muscle
two types of hypertrophy
hypertrophy: increase in muscle size
- Transient hypertrophy*
- > is the increased muscle size that develops during and immediately following a single bout of exercise
- > results mainly from fluid accumulation (edema) in the interstitial and intracellular spaces of the muscle, that comes from blood plasma
- Chronic hypertrophy*
- > refers to the increase in muscle size that occurs with long term resistance training
- > reflects actual structural change in the muscle
*resistance training leads to inc. levels of protein synthesis (inc synthesis and dec degradation during exercise; vice versa after exercise)
- > testosterone (natural anabolic steroid) and synthetic anabolic steroids facilitates hypertrophy
muscle fibre hypertrophy vs hyperplasia
fibre hyperTROPHY
inc in size of existing individual muscle fibres
fibre hyperPLASIA
- > increase in # of muscle fibres
characteristics of fiber hyperplasia
- > most hyperplasia is a factor in the hypertrophy of whole muscles
fibre hyperplasia may only occur in certain individuals under certain conditions
- > can occur through muscle fibre splitting (caused by heavy weight training)
- > also occurs through satellite cells (myogenic stem cells; involved in skeletal muscle regeneration)
short vs long term affects on fibre hypertrophy as it relates to neural activation
research has shown that early increases in strength/maximal force production are primarily associated with neural activation
Short term
- > inc in muscle strength and substancial increase in 1RM due to an increase in voluntary neural activation
- > neural factors are critical in first 8-10 weeks
Long term
- > inc in muscle strength
- > strength is more related to/associated with significant fibre hypertrophy in trained muscle
how does atrophy and inactivity affect the muscle
- > reduction/cessation of activity leads to major changes in muscle structure and function
muscle atrophy
the wasting away/decrease in size of muscle tissue caused by lack of muscle use and the consequent loss of muscle protein
how does immobilization affect the muscle
major changes are initiated when a trained muscle suddenly becomes inactive
- > changes begin as soon as 6hr after movement/workout (protein synthesis will decrease, this decrease will trigger muscle atrophy)
first week of immobilization: 3-4% strength loss per day
- > immobilization will affect both type I and type II fibres
- > these changes are reversible
detraining
the cessation of training will result in decrease of you 1RM
- > this strength loss can be regained (~6wks)
- > once regained, your RM will exceed or match the old one
- > once training goal is met, maintenance resistance programs are required to prevent the effects of detraining by providing sufficient stress to the muscles to maintain existing levels of strength
