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