S2L9 Central Fatigue Flashcards
What is Central Fatigue and how does it occur?
= reduced voluntary activation of muscle related to reduced neural output of central structures.
- increased seratonin
- decreased dopamine
- hypothermia
- hypoglycaemia
How does influencing seratonin effect performance?
- 5-HT agonist= stimulates effects. reduced endurance time
- 5-HT antagonist=inhibits seratonin. increased enfurance time
- increased seratonin = increased fatigue, decreased performance.
What are BCAAs and some examples of Branch Chain Amino Acids?
= reduces the shutting of tryptophan across the blood brain barrier
- Leucine
- Isoleucine
- valine
What happens to serotonin levels at rest in the brain?
- FFAs and Trp bind to Albumin.
- less Trp in blood than FFA
- BCAAs and Trp transported across BBB into brain - still less Trp.
- Trp = building block for serotonin
- less seratonin produced in brain
What happens to serotonin levels during exercise in the brain?
-FFA bind to albumin and push out Trp - now more Trp in blood
- Trp and BCAAs transported into brain - more Trp in brain
- so more serotonin produced - negative effect
What does supplimenting with BCAAs do?
- balanced ratio between Trp and BCAAa so less serotonin produced
- but theories suggest this doesn’t work.
What happens to dopamine levels during exercise?
-synthesis and metabolism of dopamine increases
- but decreases associated with central fatigue
- so important dopamine maintained to delay fatigue
How does supplimenting with Tyrosine effect dopamine?
- increases
- performance - supp with Tyr and CHO – decreased time but mainly due to CHO
- evidence that Tyr attenuates decrements in cognitive function
How is hypothermia associated with central fatigue?
- more exhausted and produce less force
How is hypoglycaemia related to central fatigue?
- decreased performance asso with low blood glucose levels
- glucose mouth rinse increases time trial as stomach anticipates it
