Cardiovascular response to exercise Flashcards
2 ways cardiovascular system adapts to exercise
acutely (increase o2 by blood flow)
chronically deliver more o2 to active muscle mass (more effective during submaximal)
cardiovascular factors influencing o2 uptake and vo2 max
cardiac structure and function
blood plasma volume
blood flow and distribution
o2 extraction (avo2 diff)
Fick equation
vo2 = HR x SV x (a-v)o2 difference
avo2 diff
increases during training as active muscles utilise o2 more efficiently by increasing oxidative capacity
preload
about of blood in ventricle before contraction (end diastolic volume)
what does preload determine
cardiac muscle length before contraction
afterload
the pressure against which ventricle must contract (vascular resistance)
the higher the afterload …
the less blood will be ejected per heartbeat
frank starling principle
length-tension relationship within the ventricle (greater stretch = greater contraction)
in endurance athletes, left ventricular volume is
larger
increased preload = increase stroke volume = increase eccentric hypertrophy (lengthening) so lots of blood filling
in resistance athletes what is larger
posterior wall thickness and septal thickness
increased after load = decreased sv = concentric hypertrophy
what’s stroke volume determine by
preload
afterload
contractility
what is cardiac output directly related to
Venus return and vascular resistance
endurance training sv adaptations
increase preload (ventricular filling) =
increase ventricular dimensions =
increase diastolic filling time during bradycardia =
increase contractility =
increase max sv
cardiac output adaptations
vo2max
training sub maximal decreases as increase o2 extraction
