11. Adaptations in Endurance 2 Flashcards
How do cardiomyocytes hypertrophy?
Proportional growth in length and width
How does endurance training affect the myocytes response to calcium?
Faster rise of calcium to mediate contraction
Faster decay of transient calcium rise
Explain the process of calcium release in cardiac cells
Calcium influx into t tubules leads to a release of calcium from the darcoplasmic reticulum
SerAc2a transports calcium into the Sarcoplasmic reticulum
Phospholambin (PLB) acts as an inhibitor to reduce amount of calcium accepted into SR
How does endurance training affect the calcium pumps in the cardiac myocytes?
SERC2a calcium pump increased in response to training
PLB total remaimns unchanged however phospholryated lambin increased
This is due to increased calmodulin kinase causing increased calcium re-uptake
How does caclium sensitivity of cardiac myocytes change in endurance training?
Requires less calcium to achieve half max tension
=more sensitive to calcium
What effect does endurance training have on the blod?
Heamatocrit is reduced but RBC are increased
Blood is less vicous
Decreased resistance to flow
Enhanced oxygen delivery
What causes increase in blood due to endurance training?
Increased plasms volume (ADH, aldosterone, albumin)
Increased red cell volume (EPO)
Discuss the time courses of blood changes in reponse to edurance training
Plasma volume- almost immediate—6 weeks
RBC- 3 weeks, equilibrum reached at 6 weeks
How does Red blood cell volume contribute to VO2 max
Increase in RBC cells mirrors increase in VO2 max
Why does blood flow to muscles increase more in trained individuals?
Increased vasodilation and
greater capillary density
Why are trained atheltes able to utilise more oxygen from the blood
Aerobic enzymes increase by 2 fold
Mitchondrial biogenesis increases (no. o mitochondria)
Capillary density increases by 40%
