Chapter 4 - Acute responses to exercise Flashcards
define acute physiological response to exercise?
am immediate response to exercise with the respiratory, cardiovascular and muscular systems that last for the duration of exercise and recovery
what is ventilation? at rest versus during maximal exercise?
air breathed in and out per minute
rest = 6L/min
maximal = 192L/min
how is ventilation calculated?
v = tidal volume x respiratory rate
what happens to ventilation when exercise intensity increases?
ventilation increases, from the increase in RR and TV. At sub-max exercise ventilation increases rapidly at the start and then more slowly until it plateaus, can be 15-30 litres more than at resting levels
what is tidal volume? at rest versus during maximal exercise?
amount of air inspired and expired per breath
rest = 0.5L
maximal = 4L
what happens to tidal volume as exercise intensity increases?
it increases, however plateaus at high intensities.
what is respiratory rate? at rest versus during maximal exercise?
breaths per minute
rest = 12
maximal = 48
what is gas exchange?
the movement of gases in and out of the circulatory system, moving from high to low concentration
what happens to gas exchange during exercise?
it increases so that greater amount of oxygen and carbon dioxide can be exchanged. this allows for greater amounts of oxygen to be available at the muscle and for greater amounts of carbon dioxide to be removed
define oxygen uptake? during rest?
the ability to consume oxygen for energy consumption
rest = 0.3-0.4 L/min
what is stroke volume? rest versus maximal intensity?
the amount of blood pumped out of the left ventricle of the heart per beat
rest = 75ml/beat
maximal = 112ml/beat
what happens to stroke volume when exercise intensity increases?
it increases due to increased demand for oxygen at working muscles, however plateaus at sub-maximal intensities, left ventricle can’t pump out blood any faster
what is heart rate?
beats per minute
what happens to heart rate when exercise intensity increases?
increases until maximum heart rate is achieved
what is cardiac output? rest versus maximal intensity?
litres of blood pumped out of left ventricle per minute
rest = 6.2l/min
maximal = 22.4l/min
what happens to cardiac output when exercise intensity increases?
it increases due to increased heart rate and stroke volume
what is systolic blood pressure?
represents the maximum pressure exerted in the arteries when the heart contracts, is the top figure
what is diastolic blood pressure?
force by blood on arterial walls during ventricular relaxation, bottom figure
what happens to blood plasma volume during exercise?
decreases
what happens to the distribution of blood flow during exercise?
redirected away from organs towards working muscles
what is a-vo2 difference?
the difference between oxygen concentration in the arteries vs the veins
what happens to a-vo2 difference during exercise?
increases because a greater amount of oxygen being extracted by working muscles from the arteries leaving less in the veins
how does vasodilation and vasoconstriction assist in redistribution of blood during exercise?
vasodilation allows for an increase of blood flow to working muscles, vasocontriction decreases the amount of blood going to non-essential areas
what is motor unit recruitment?
during exercise the force of working muscles increases, during exercise more motor units are required to produce more force, the number of units recruited depends on the level of force required
what happens to energy substrates during exercise?
they decrease: pc, glycogen, triglycerides, atp
what happens to the production of metabolic by-products during exercise?
they increase
what happens to body temp during exercise?
increases due to breaking down energy which produces heat as a by-product
what is oxygen deficit?
The amount by which oxygen consumption does not meet oxygen demand. The lag in oxygen uptake before steady state is achieved.
what is steady state?
oxygen demand = oxygen supply, only occurs at or below LIP (85% max HR)
what is EPOC?
aka oxygen debt. EPOC mean the volume of oxygen consumed during recovery above ordinary resting level. The size of EPOC is proportional to the intensity and duration of the exercise.
what are the two stages of EPOC?
Alactacid oxygen debt = restoration of PC stores
Lactacid oxygen debt= removal of accumulate LA
what is aerobic capacity?
This is the ability of the body to utilise oxygen to perform work or exercise. Depends on the efficiency and development of the cardiovascular and respiratory systems
what is vo2 max?
The maximum amount of oxygen being taken in, transported to and consumed by the working muscles to produce ATP. measured in ml/kg/min
when do we reach our vo2 max?
body can’t increase the amount of oxygen it consumes and utilises, this is your VO2 max
what causes ventilation to increase?
an increase in tidal volume and respiratory rate
what are 2 factors that will affect an individuals vo2 max?
- aerobic fitness: Vo2 max is determined by the heart circulatories ability to utilise oxygen
- body size: heaver person have larger vo2 max consumption
