chapter 5 Acute physiological responses to exercise Flashcards
(29 cards)
define acute responses
Short term physiological changes during exercise to meet energy demands.
Define variation
responses depend on exercise intensity and duration
what does the purpose do
highlights how these systems supply oxygen and energy to working muscles
What is oxygen uptake (VO2)
Is the amount of oxygen transported to, taken up by and used by the body for energy production.
What is VO2 max
the maximum amount of oxygen per minute that can be taken in, transported and used by the body for energy production.
what is the average oxygen uptake at rest
approximately 0.25-0.3 litres per minute.
What fuels are used at rest for ATP production?
Carbohydrates and fats - as it is used to resynthesise ATP aerobically when the body is at rest
what happens to oxygen uptake when exercise begins
It increases to meet the higher energy (ATP) demand for oxygen by the working muscles.- The respiratory and cardiovascular system respond by increasing breathing rate, heart rate and blood flow to deliver more oxygen. However there is a short delay before oxygen supply fully matches demand - which is oxygen deficit.
what is the relationship between oxygen uptake and exercise intensity
it is linear, as intensity increases, oxygen uptake increases until VO2 max is reached
what is oxygen deficit
A shortfall between the oxygen required and the oxygen supplied at the beginning of exercise
Why does oxygen deficit occur
this occurs because the respiratory and circulatory system need time to adjust to the new oxygen demands.
What energy systems are relied on during oxygen deficit
The anaerobic energy system.
What is steady state oxygen consumption
A pint during exercise where oxygen supply meets oxygen demand
What is EPOC
Excess post exercise oxygen consumption- the increased oxygen intake after exercise to return the body to resting state.
What does EPOC help restore
helps restore ATP-PC stores and remove lactate and return body systems to resting levels.
what is steady state
a state during exercise when oxygen supply equals oxygen demand, allowing almost all ATP to be resynthesised aerobically
How long does it take to reach steady state
between a few seconds and over a minute, depending on exercise intensity
what happens if exercise intensity increases after reaching steady state?
oxygen demand increases again, causing another oxygen deficit until a new steady state is reached.
why does EPOC occur
To restore the body to pre-exercise conditions, including ATP-PC replenishment, lactate removal, and cooling the body.
5 factors that increase EPOC
- elevated muscle temperature
- increased mitochondrial activity
- continued ATP production
- CP restoration
- lactate removal
Why is VO2 max often expressed in mL/kg/min?
To compare aerobic fitness between individuals of different body sizes.
5 factors affecting VO2 max
body size
gender
genetics
age
training status (aerobic fitness)
Why do females typically have lower VO2 max then males?
Because females have higher body fat % and lower muscle mass, lower blood volume and haemoglobin levels as well as a smaller heart and lung size
How much of VO2 max is influenced by genetics
25-50% of the variation between individuals.
