Lecture 30 Flashcards
Physiology of Aerobic Fitness and Training Adaptations
why is aerobic fitness important
- health and wellness
- performance
- survival
- extreme environments
- help prevent and also treat several conditions
we need to keep resynthesising ATP to support 3 types of work, what are they
cell transport processes, mechanical work, and chemical work
what are the 4 main ways to increase ‘aerobic fitness’
- increase VO2 max (aerobic power)
- increase ‘anaerobic’ threshold (max sustainable power)
- increased economy
- increased endurance capacity (max duration at a given power)
why measure max aerobic power …. major determinant
it is a major determinant (and therefore also predictor) of endurance performance
why measure max aerobic power
sets the upper limit for producing ATP aerobically
tests the response capacities of almost all systems
suitability for surgery
exercise prescription and monitoring training outcomes
what is direct measurement of aerobic power (what to measure and when the participant will stop)
measure VO2 and rate of CO2 production
the participant will stop when :
- fatigue
- plateau VO2 despite increasing intensity
- HR within 10 bpm of age predicted max
- RER > 1.1
- RPE > 18 or 20
how long will VO2 max be and why
around 8-12 minutes in duration because duration must allow full activation of aerobic metabolism in muscle not too long
what are ways to measure non/sustainable thresholds
- max sustainable pace (e.g pace you can hold for 30 mins)
- ventilatory thresholds
- lactate curves
people that are fitter have what O2 and energy at matched speed or power
decreased O2 and energy needed
change in VO2 is equal to =
change in VO2 = cardiac output x oxygen extraction
in the equation of change in VO2 what are the central components
O2 delivery : heart rate and stroke volume
in the equation of change in VO2 what are the peripheral components
O2 extraction
higher VO2 maxes have higher what
cardiac output
what aspect of your heart rate can you change and what cant you
can decrease the minimum but can not change the maximum
what are 5 factors that influence O2 delivery
- alveolar ventilation (tidal volume and breathing frequency)
- cardiac output
- oxygen carrying capacity
- capacity of arteries and arterioles
- capillarisation
is ventilation trainable
yes and no
what is a reason as to why ventilation could be trainable and how
decreased ventilation at a given VO2
- deeper breaths in trained (therefore decreased ventilatory threshold than untrained)
what is a reason related to respiratory muscles as to why ventilation could be trained and how
increased respiratory muscle resistance to fatigue
what is a reason as to why ventilation is not trainable
little effect on ventilation at max effort
pulmonary ventilation isnt normally a limiting factor
pulmonary ventilation isnt normally a limiting factor except when :
- obstructive pulmonary disorders
- some elite endurance athletes
- extended strenuous exercise
stroke volume increases due to training because of what several local factors
- increased left ventricle capacity
- increased left ventricle mass
- increased compliance
- increased capillarisation
- increased anti-oxidant capacity
what does increased left ventricle capacity mean related to stroke volume
gives increased diastolic volume
increased compliance of the heart means what
- faster relaxation (filling)
- less passive resistance to shortening
why would rowers have higher increased ventricular wall thickness, volume and mass
rowing involves endurance and strength, leading to thicker walls and volumes
is it clear what you should overload for optimal cardiac adaptations
no it is not clear
increased pre load with aerobic training is due to
- increased blood volume
- increased time for filling (decreased heart rate)
increased pre load of the heart means more what (due to what law)
means more stretch so stronger contraction (frank starlings law)
aerobic training allows for increased time for filling when, due to what which allows for ….
at rest and during submaximal exercise due to decreased SNS and increased PNS
this allows for greater contractibility
what does increased blood volume mean in terms of stroke volume with aerobic training
increased blood volume means you can get more blood back to the heart (increased venous return) and therefore can increase stroke volume
what is meant by decreased afterload with aerobic training
decreased arterial pressure
what does decreased afterload with aerobic training allow for
higher ejection fraction since less work needed to eject blood
what is decreased afterload from aerobic training due to
- no change or reduced total peripheral resistance
- increased arterial capacities
- increased arteriole reactivity
- increased capillarisation
aerobic training leads to what change in heart rate and what is the likely cause of this
lower heart rate at rest, and all submaximal intensities
likely due to increase PNS and decreased SNS
lower heart rate rest is more vulnerable than what
than higher max
what is lower heart rate rest more beneficial than heart rate max
more filling time (increased stroke volume)
lower O2 and energy demand
