Exercise Physiology Flashcards
innervation ratio
number of muscle fibers innervated by single motor neuron
muscles with high IR
gastrocnemius
quadriceps
for sprinting and jumping
more excitable, conducts action potentials more slowly
small-diameter motor neuron
less excitable, conducts action potentials more rapidly
large-diameter motor neuron
strength (anaerobic) training motor unit
Type IIx motor unit
endurance (aerobic) training motor unit
type I and type II a
work formula
force X distance
power formula
work/time
force developed by cross-bridges exceeds external load, sarcomeres shorten
concentric contraction
force developed by cross-bridges is less than imposed load, sarcomeres lengthen
eccentric contraction
what muscle contraction puts more stress on muscles –> damage muscle fibers and CT?
eccentric contraction
common eccentric contraction muscle injury
rupture of achilles tendon
strength of muscle is determined by ____.
muscle size and testosterone level
what does endurance of muscle depend on?
nutritive support = amount of glycogen stores
high carb diet glycogen stored in muscle (g/kg)
40
mixed diet glycogen stored
20 g/kg
high fat diet glycogen stored
6 g/kg
products of phosphagen system
ATP and phosphocreatine
immediate energy source BUT LIMITED
what is the effect of decreased pH on contractile force of muscle?
it impairs contractile force of muscle.
central CNS fatigue is less likely to occur in what kind of individuals?
highly trained athletes
central CNS fatigue is more likely to happen in..
novice athletes/individuals
what kind of external stimulus will increase muscle force production and physical performance?
sensory input – shouting and cheering
cause of peripheral fatigue
impaired excitability, impaired calcium release
reduced excitatory input to motor centers of brain and SC can lead to
central CNS fatigue
