Factors affecting maximal performance and ergognenic aids Flashcards
what are potential sites of fatigue that may impair tension development?
central fatigue: CNS
peripheral fatigue: neural factors, energetics of contraction, mechanical factors
is there evidence that CNS may contribute to fatigue?
yes
the evidence that it didn’t was disproved so it absolutely does
- electrical stimulation CAN produce more tension in the muscle
-CNS can have arousal when opening eyes
when looking at peripheral fatigue, what neural factors may contribute?
- neuromuscular junction is NOT A LIKELY STIE OF FATIGUE
- the sarcolemma and t-tubules: cannot maintain Na+ and K+ contractions.
- the Na and K+ pump cant keep up and gets blocked
- less Ca++ is released and impaired myosin cross bridge activation
- WITH TRAINING IT CAN HELP
How does high H+ concentrations effect muscle tension?
H+ interferes with cross bridge formation and is potent chemical fact.
-it reduces the force generated at a given CA++ concentration
Why is the recruitment profile of muscle fiber types dependent upon exercise intensity?
type 1: slow oxidative @ 40% VO2 max- relys on mitochondria
type 2a: fast oxidative glycolytic @ 40-75% VO2 max -depends on O2 delivery- relies on glycolysis
type IIx: fast glycolytic @ 75% VO2 max. low mitochondria but high force production (increased lactate production and increased H+ ions)
what factors affect fatigue for performances lasting >1 hour?
- diet.
- supplement during exercise
- VO2 max
- dehydration
- heat load
- running economy (biomechanics and bioenergetics)
what causes DOMS and how do you prevent it?
- bout of unfamiliar exercise results in DOMS
- strenuous muscl contraction which damage membranes
- calcium leaks from the SR into the mitochondria inhibiting ATP
- edema and histamines stimulate pain receptors
- NO COUNTER MEASURES ARE EFFECTIVE such as ibuprofen or creatine supplementation
- DOMS is due to microscopic tears in muscle fibers or conn. tissue which results in cellular degradation and inflammatory response
DOMS is due to Lactic acid buildup?
FALSE: DOMS is due to microscopic tears in muscle fibers of conn tissue which results In cellular degradation and inflammatory response
-you can avoid DOMS by slowly beginning specific exercise training for the first 5-10 training sessions
what is blood doping and how does it affect endurance exercise performance?
increasing number of RBC
- it can greatly increase performance with endurance exercise
- blood doping improves performance by 15-37%
how can caffeine improve performance?
can decrease RPE
- increase tension
- increase FFA mobility
- ** by using phosphodiesterase, caffeine can increase output of 3 FFA + glycerol
true or false: there are no gender differences in response to short term strength training
True: the only difference is in long term strength training
true or false: men have more muscle mass than women and their cross sectional areas are different
FALSE: men have more muscle mass, but their cross sectional area between men and women are similar!
what percent of athletes report using supplements?
50% of adults report using supplements
groups in which protein supplementation has been found to be useful with resistance training
elderly and cancer patients
breathing pure O2 before or after exercise has ___ effect on performance
zero effect on performance
-may increase performance during tho
