pe ch 4 Flashcards
What are acute responses?
they are immediate responses to exercise.
what are the three systems that respond to exercise
- respiratory
- cardiovascular
- muscular
What are the respiratory responses to exercise
- increase ventilation
- increase tidal volume(plateaus at higher intensities)
- increase respiratory rate
- increase in diffusion
what is the aim of respiratory responses?
to get more oxygen in the body.
what is ventilation and how to we find its value?
Ventilation is the amount of air breathed in one minute
tidal volume x respiratory rate
What is respiratory rate?
respiratory rate is the number of breaths taken in one minute.
What is tidal volume?
tidal volume is the amount of air taken in one breath.
what happens to tidal volume as intensity increases?
tidal volume will plateau.
What are the cardio vascular responses to exercise?
- increase in HR
- increase in stroke volume
- increase in cardiac output
- increase in systolic blood pressure (greater with high intensity)
- no change in diastolic blood pressure
- increase in venous return
- decrease in blood volume
- increase in a-VO2 difference
what is diffusion?
Diffusion is the exchange if gas between alveoli to the capillaries in the lungs or vise versa.
what is stroke volume(SV)
SV is the amount of blood ejected by the heart each beat
roughly around 70 ml at rest
what happens to SV at submaximal exercise, and why?
it will then decrease because HR is so fast it does not have enough time to fill and eject blood.
What is the formula for cardiac output?
HR x SV- the amount of blood ejected by the heart per minute.
what is systolic and diastolic blood pressure?
systolic- pressure in the arteries as the heart beats
diastolic- pressure in the arteries as the heart relaxes
why does blood volume decrease with exercise?
This is because of the loss of plasma content via sweat, thus the rate of loss is dependent on the hydration of the individual
why does venous return increase with exercise?
Because the muscles are contracting at a higher rate with exercise, this will force venous return to increase as the veins force more blood back to the heart.
why does AVO2 diff increase with exercise?
This is because the muscles will consume more oxygen during exercise meaning there will be less o2 in the veins.
what is the percentage of blood muscles get during exercise
84%
What are the muscular responses to exercise?
- increase in motor unit recruitment
- increase in blood flow to working muscles
- increase in body temp
- decrease in ATP, CP, Glycogen and triglycerides
- increase in lactate production
when exercise begins what fuels the muscles?
ATP stored in the muscles
What is oxygen deficit?
When the oxygen supply does not equal the demand due to insufficient amounts of oxygen being available in the body.
How is the body working during oxygen deficit?
Anaerobically.
What is steady state?
When the oxygen supply is equal to demand, usually when the aerobic system is meeting the task.
What happens HR, BP, Q and VE in a steady state
They will all plateau
What is Excess post oxygen consumption (EPOC)?
Also known as oxygen debt, this is the oxygen consumed after exercise that still remains above the amount required for resting levels
what is the formula for oxygen debt?
VO2 used during recovery - resting VO2
What does the EPOC fast replenishment restore and how long does it take?
This stage primarily restores phosphocreatine(PC) and takes aprox. 2 to 3 minutes.
What is the purpose of EPOC slow replenishment?
Its primary concern is to remove lactic acid that has been accumulated through exercise.
What is VO2 max
The maximum amount of oxygen that can be taken up, transported and utilised in one minute.
Describe the relationship between oxygen uptake at rest, during exercise and recovery
Rest: supply equals demand
Exercise: increase in uptake to meet the demands of the activity, we often see an oxygen deficit at the start of exercise as oxygen supply does not equal demand.
Recovery: The consumption of oxygen to return the body systems to normal resting rate.
Why does oxygen supply not equal demand on the onset of exercise, resulting in an oxygen deficit.
This is because the aerobic system which is responsible for transporting oxygen, takes time to become active. Therefore we have to supply our bodies anaerobically which eventually transfers to aerobic.
What are some acute responses that enable steady state to be achieved?
Increase in HR, Q, BR, diffusion and distribution of blood flow.
What are the acute responses of submaximal exercise
- Reach steady state
- Lower O2 deficit and EPOC
- HR increase to steady state
- Q, SV, TV, VE and diffusion increase
- reduction in fuel (glycogen)
- increase in body temp
- recruitment of more muscle fibres
- increase in AVO2 diff and venous return
What are the acute responses of maximal exercise
- high O2 deficit and EPOC as more reliant on anaerobic activity
- steady state no reached
- HR increase to max
- SV and TV will decrease
- reduction in muscle substrates (ATP, PC)
- max recruitment in muscle fibres
- increase lactate production
- increase in AVO2 diff and venous return.
what is vasoconstriction?
this is a decrease in the diameter of the blood vessel, resulting in a decrease in blood flow to the area supplied by the blood vessel
what is vasodilation?
this is a increase in the diameter of the blood vessel, resulting in a increase in blood flow to the area supplied by the blood vessel
what is stroke volume compared to an untrained individual compared to a trained athlete.
Untrained: 75 mls per beat
trained : 105 mls per beat
what is heart rate compared to an untrained individual compared to a trained athlete.
untrained : 82 bpm
trained : 58 bpm
how can muscular fatigue occur as a result of acute muscular responses.
muscular fatigue can occur due to the accumulation of lactic acid, this is dependent on ones tolerance to it and how fit they are.
