lecture 30 Flashcards
why is aerobic fitness important?
health and wellness
performance in rec, sport and industry
extreme environments (heat)
help prevent and treat several conditions
what are examples of conditions that aerobic fitness can help prevent and treat.
cancer, insulin resistance, T2DM, CHD, depression
four ways to increase aerobic fitness
INCREASE
vo2 max
anaerobic threshold
economy
endurance
how much can vo2 max increase by
5-30%
how much can you increase economy
5-10%
how much can you increase anaerobic threshold?
from 60-70%. to 80-94% of vo2 max
what are the two key mediators for endurance athletes and how do these increae over time
vo2 and aerobic threshold
increase in vo2 max is smaller but faster than the increase in threshold.
can someone excel in all factors/determinants in aerobic fitness
rare for someone to
why measure max aerobic power?
major determinant of endurance performance in many contexts
sets the upper limit for producing ATP aerobically
tests the response capacities of almost all systems
suitability fro surgery
exercise prescription and monitoring training outcomes.
what do you need at least two of to measure max vo2.
fatigue, plateau vo2
hr within 10 bpm of age-predicted max. RER> 1.10 RPE >18/20.
how to measure non/sustainable thresholds of aerobic capacities?
max sustainable pace e.g for 30 minutes.
a crictical power curve
ventilatory thresholds
lactate curves
informally: <15/20
efficiency =
work rate/metabolic rate *100
what happens if you increase economy.
will be able to have a decrease in o2 at matched speed or power.
decrease in heat load, dehydration, glycolysis.
is economy a short term effect?
no long term effect and small.
how to measure economy?
energy use or vo2 at steady state power and speed.
what does CO * o2 extraction =
vo2
which part of the vo2 equation is o2 delivery
the cardiac output (HR *SV)
and (Ca) in o2 extraction. this is from the central
what is the o2 extraction equation.
(CaO2-cvO2)
cao2 is the arterial
cvo2 is the venous
peripheral aspect of vo2
factors that influence o2 delivery
alveolar ventilation
cardiac output
oxygen carrying capacity.
capacity of arteries and arterioles
capillarisation.
why is Ve trainable ?
yes: decrease Ve at a given VO2. (deeper breaths - helps alveolar ventilation)
yes: increase respiratory muscle resistance to fatigue.
why is increase respiratory muscle resistance to fatigue helpful
maybe important in very hard sustained or repeated exercise.
why is ventilaition not trainable
little effect on ve at max effort. as ventilation isnt normally a limiting factor for max effort
when is ventilation a limiting factor for max effort
obstructive pulmonary disorders
some elite endurance athletes
extended strenuous exercise.
what are the local factors that increase stroke volume
increase all
left ventricle capacity
left ventricle mass
compliance
capilarisation
anti oxidant capacity
how much can the left ventricle increase in mass
around 20%
how would increase ventricle capacity increase SV
gives increase in end diastolic volume
how would left ventricle mass increase sv
allows increase contractility (force generated)
how does increase compliance in the heart increase SV
faster relaxation
less passive resistance to shortening
how does anti-oxidant capacity in the heart effect SV
protects cells against prolonged ischaemia and reperfusion
what sport has the highest ventricle thickness, volume and mass
rowing.
external factors allowing increase SV aerobic training. with preload
increase BV (venous return)
increase time for filling (decrease HR). due to increase SNS and decrease PNS.
what does pre load mean
increase preload means more stretch so stronger contraction
external factors allowing increase SV aerobic training. with after load
decrease after load.
decrease BP
decrease TPR ( decrease SNS at reat and e)
increase aterial capacities
increase capillarisation
what is afterload
decrease afterload allows higher ejection fraction since less work needed to eject blood.
what would decrease in afterload mean
decrease in arteriol blood pressure
what is more valueable to change HR rest or higher max HR and why?
lower HR rest.
gives more multiples of increase to HR max.
more filling time (increase SV)
lower o2 and energy demand
three ways to use HR
HR
%HRmax
%HRRange
