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3.1 KiB
3.1 KiB
Muscle Fatigue
"decrease of a muscle's ability to maintain tension/power over time"
no oxygen -> that makes lactic acid
lactic acid is short term
fatigue - can no longer preform level of activity
often oxygen debt
recover period, failure / rest
preform glycolysis, liver breaks down lactic acid into glucose USING ATP (only works in rest period) cori cycle
muscles have different fiber types - therefore has different fatigue
- type I - slow oxidative
- type IIa - fast oxidative
- type IIx - fast glycotic
all muscles have all fivers, density is the key differentiators
Slow oxidative Muscle Fibers (Type I)
- "slow twitch"
- works in oxygen, and moves slowly
- structural characteristics
- small muscle diameter
- more vascularity/high capillary density + high mitochondria density -> aerobic!
- Metabolic characteristics!
- take three times longer to contract ( slowest of all fibers) -> sustained movement (fatigue resistant)
- impulse to move is 3 times slower than others
- contains myoglobin -> stores oxygen (short term)
- take three times longer to contract ( slowest of all fibers) -> sustained movement (fatigue resistant)
- function
- first muscle fibers to be recruited (low power)
- run marathons (can be used for hour+)
- anti-gravity + posture muscles
- basically hard to wear out. the marathon muscle
fast oxidative fibers (type IIa)
- structural characteristics
- humans largest diameter muscle fiber
- highly vascularizaion + high density density of mitochondria -> aerobic!
- high density of muscle glycogen / some myoglobin
- Metabolic characteristics
- can utilize anaerobic respiration
- glycolysis
- creatine phosphate to ADP = some ATP
- can add some extra fatigue resistance to the muscle
- fast contractility -> moderate fatigue resistance
- can utilize anaerobic respiration
- function
- 2nd recruitment order -> moderate power
- walking/sprinting (longer than one minute, shorter than 30 minutes)
Fast Glycolytic (Type IIx)
- Structural Characteristics
- intermediate diameter (humans)
- "white fibers" -> paleish pink
- very little vascularity , mitochondria -> almost no aerobic respiration
- high muscle glycogen / little to no myoglobin
- use as much energy as fast as possible
- metabolic characteristics
- primary anaerobic
- Glycolysis
- Creatine phosphate + ADP = some ATP
- Fastest Contractily -> Lowest fatigue resistance
- makes some ATP quickly -> uses it much faster
- primary anaerobic
- function
- 3rd recruitment order -> highest power
- heavy weight training / burst power (less than 60 sec)
Changes in density
- genetics + enviornmental stress
- hypertrophy vs atrophy
- changes density of muscles
- endurance exercise (trend to type Ia)
- angiogenesis (increase amount of blood vessles to the muscles)
- increase myoglobin + mitochondria
- resistance exercise (trend to type II's)
- damage leads to increase in mass
- literally split muscle fibers -> repaired bigger
- increase in myofibrils )size and number)
- increase in glysosomes (store glycogen))
- strengthens Connective Tissue, tendons, and bones
- damage leads to increase in mass
basically as you train, the muscles work on making it easier by handling those
muscle memory: going back to state of athletic state, enviornmental stress