Chapter 10: Adaptations to resistance training
Effect of strength training on strength
40% increase in strength over 10 weeks
Immobilization: major changes after 6h, first week, effects on type I and type II fibers
6h: reduced rate of protein synthesis, initiates process of muscle atrophy first week: strength loss of 3-4% per day, decrease in size and neuromuscular activity (Reversible) effects: decreased CSA, cell components degenerate. Type I more affected than type II
Fiber type alterations (not conversion)
Fiber types stay the same, but their characteristics may shift to resemble a different type (i.e. type II fibers become more oxidative with aerobic training)
Higher intensity exercise leads to type ___ fiber hypertrophy
II
Effects of immediate ingestion of protein post-exercise vs delayed ingestions (2h post-exercise)
Immediate ingestion increases CSA to a much greater extent
Improvements in resistance training are related to:
Intensity Repetitions Frequency
Strength increases in older adults depend primarily on _____________ ______________.
Neural adaptations
Muscle plasticity
cross sectional area changes with training. Type II fibers increase more than Type I
Atrophy
decrease in muscle size and strength
Detraining
decreases 1RM (but can be regained with retraining)
Transient hypertrophy
due to edema formation from plasma fluid
Short term increase in muscle strength
due to increase in voluntary neural activation, neural factors critical in first 8-10 weeks
BCAAs and insulin _____________ protein synthesis
increase
Hypertrophy
increase in muscle size and strength
Fiber hyperplasia
increase in the # of muscle fibers, can occur through fiber splitting or through satellite cells (triggered by stretch, injury)
Strength gains after the first 3 weeks of training occur primarily because of ___________
increased muscle mass
Strength gains in the first 3 weeks of training occur because of _____________
increased neuromuscular efficiency
___________ & increased muscle CSA are primarily responsible for strength gains from resistance training
increased neuromuscular efficiency
Fiber hypertrophy causes
more myofibrils (only in animals) more actin & myosin filaments more sarcoplasm more connective tissue increases in contractile protein synthesis
The difference in strength between men and women is not due to quality of muscle, but rather due to _____________
muscle mass
Effect of endurance training on strength
no change in strength
Effect of strength + endurance training on strength
paralleled strength training for ~8wks, then leveled off
Chronic hypertrophy
reflects actual structural change in muscle, maximized by eccentric training
Golgi tendon organs
sense strain on muscles and prevent contraction if tension is too high to prevent damage, but training may decreases these inhibitory impulses
Long term increase in muscle strength
significant fiber hypertrophy, increase in net protein synthesis takes time, hypertrophy is a major factor after first 10 weeks
Synchronous recruitment results in ______________
strength gains