acute responses to exercise Flashcards
acute responses
when exercise begins, increased demand for energy
in response bodys respiratory, cv and muscular systems experience a series of change to meet new energy requirements
respiratory response description
increase volume of oxygen taken in at lungs
lugs and airways is responsible for taking in O2 and expelling Co2
increase oxygen available to be transported to and utilised by the body
respiratory responses
respiratory rate
ventilation
tidal volume
pulmonary diffusion
respiratory rate
number of breathes per minute
tidal volume
volume of air breathed in and out in one breathe
ventilation
volume of air breathed in per minute
TV x RR
pulmonary diffusion
increased activation of alveoli results in more sites being available for gas exchange between lungs and bloodstream
meaning more occurring, results in increased oxygen uptake
cardiovascular response description
when exercise starts, aim is to increase the volume of oxygenated blood delivered to working muscles
will increase oxygen available to be utilised by body
speed up removal of Co2 and waste products
cardiovascular responses
heart rate stroke volume cardiac output blood pressure venous return A-Vo2 difference blood volume redistribution of blood flow
heart rate
number of beats of the heart per minute
stroke volume
volume of blood pumped per beat of the heart
cardiac output
amount of blood pumped out of the left ventricle of the heart per beat
blood pressure: systolic
the pressure exerting by the blood against the arterial walls when heart contracts
increased in blood exiting heart= increase in blood pressure is higher when doing strengthening exercise
redistribution of blood flow
altering the % of cardiac output that is distributed to various body sites
during exercise blood flow will increase to the heart and working muscles
less blood going to internal organs
this happens due to vasoconstriction is narrowing of blood vessels
vasodilation is opening of blood vessels
venous return
allows required increase in stroke volume and cardiac output that exercise demands
when exercise begins= increase in venous return
A-Vo2 difference
difference in concentration of oxygen in the arterial blood and venous blood
blood volume
body temp regulated by sweat
fluid comes from plasma in blood
reduces overall volume of blood in the system
and inhibits blood flow around the body
fast twitch fibres
used for short explosive bursts of energy
little need for oxygen
more power, stored ATP, fatigue quicker
fast contraction time
slow twitch fibres
have greater capacity to use O2 so are used for longer, less intense activities more stored glycogen oxidation enzymes high capillary density increased mitochondria
muscular responses
motor unit recruitment muscle temperature oxygen uptake and consumption (V02) energy substrate stores metabolic by products
motor unit recruitment
1 motor unit= 1 motor neuron and all muscle fibres it stimulates
during exercise, amount of force developed in working muscles increases
increase in force production occurs by increasing number of motor units stimulated or increasing frequency of messages to arrive at motor unit
muscle temperature
heat= by product of aerobic e.p
exercise begins and rate of energy production increases, so does body temp
warm up prior to events allows muscle temp to increase including muscle elasticity, flexibility and reduce risk of inury
regulating body temperature can become a fatigue factor in prolonged events or in hot environments where blood required to be redistributed to the skin to facilitate heat loss
oxygen uptake and consumption (V02)
the volume of oxygen the muscles consume increases as the intensity of exercise increases
energy substrate stores
ATP-ANG-AG
all available fuel sources within the muscles decrease as exercise is undertaken
duration and intensity of exercise which fuels and fibre types are preferentially used
therefore impact on the degree of fuel used
this response can have implication on performance in fatigue factor of fuel depletion is experienced
metabolic by-products
lactic acid is produced at rest and during exercise
however it is the balance between lactic appearance and removal that determines the extent to which it will impact on performance and sport
LIP
why does ventilation increase
respiratory system is responsible for o2 delivery and co2 removal
at start of exercise=breathe in deeper
muscles aim to stimulate it by sending messages to r.s in which brain increases TV and RR
ventilation at sub max exercise
increase rapidly at start and then slowly until plateau 4-5min
ventilatory threshold
point where v can no longer increase linearly with increase exercise in exercise intensity
basis of cardiovascular responses
focus on getting blood to working muscles to deliver greater amounts of oxygen and energy substrates
trained heart rate
lower heart rate and increased SV
venous return parts
vasoconstriction
muscle pump
respiratory pump
valves/vasoconstriction
one way movement of blood
muscle pump
constriction of blood vessels to force blood along when muscles contract
respiratory pump
breathing in difference in pressure force blood to flow through veins. increase pressure= increased flow
