Respiratory system and exercise 2 Flashcards
importance of VT/LT
workloads at which they occur are highly related to endurance training and performance
AT is correlated with
performance endurance events like 10km/marathon
thresholds can be used for 2
purpose of exercise prescription/training intensity
1 - mod
2 - heavy but sustainable
prediction of performance
incremental aerobic exercise to VO2max effect on external respiration (2)
gas change is generally not a limiting factor in maximal exercise - increased pAO2 with increased f exercise induced arterial hypoxemia - some ind experience significant decrease in PaO2 and SaO2 mild 93-95% SaO2 mod - 88-93 severe - less than 88% - limits capacity increased A-aPO2
4 possible mechanisms for EIAH
transition time too fast (ventilation-perfusion mismatch)
capillary damage during shear stress for high hematocrit and increased Q
quality of air - cold/dry/polluted
potentially intrapulmonary anatomical blood vessel shunts that bypass alveoli during intense exercise
transition time in pulmonary capillaries
rest =0.75 seconds
complete gas exchange = 0.3-0.35 seconds
max exercise transit time = 0.3-0.4 seconds
- seems that there is enough time for O2 and CO2 exchange at all levels of exercise , but this might not always be true
transport time between pulmonary and muscle capillaries
similar
exercise induced pulmonary hemorrhage
experienced by some thoroughbred horses - high BP due to high Q causing rupture of pulmonary capillaries - resulting in blood leaking into alveoli
brochoalveolar lavage after exercise in cyclists
4km uphill sprint - increase level of RBC
77% submax - no detection of RBC
conclusion - brief intense exercise compromises integrity of blood gas
athletes have tasted blood or had iron taste their mouth after intense exercise
run until you taste blood - smell of iron from the alveoli triggering the smell/taste receptors - not conclusive
incremental aerobic exercise to VO2max on internal respiration (2) PO2 PvO2 aVO2 PCO2 PvCO2 oxygen to mucls alveolar o2 PaO2 PaCO2 SvO2
PO2 in active muslce falls toward 0 - pvo2 decreases
- avo2 increases
PCO2 approaches 90 - pvCO2 increases
amt of O2 released to muscles increased by 3 times of resting level
increase in alveolar o2 - decrease ventilation because you increase frequency but decrease tidal volume
PaO2 increases slightly
PaCO2 decreases
svO2 decreases
recovery of VE (4)
VE remains elevated after exercise and decreases in relation to the fast and slow phases of EPOC
fast - rapid decrease - 2-3 mins
slow - slow decrease - 3-60 min
getting rid of heat and getting in o2
exercise response to static exercise (2)
a-vo2 diff i limited due to occluded blood flow - limited perfusion to tissues - cant get rid of metabolic byproducts
or use it as signals, some proprioceptors for stimulation
upon cessation there is a rebound in VE and a-VO2 diff (metabolic byproducts stimulated)
entainment (4)
synchronization of limb movement and breathing frequency that accompanies the rhythmical exercise
- naturally in some athletes
- forces in sports like swimming
- elicit a slightly improved ventilatory efficiency which can reduce fatigue
should you consciously control breathing during exercise
challenging to train and not much improvement
side stitch and 4 potential causes
exercise -related transient abdominal pain
- decreased blood flow to diaphragm
- subdiaphragmatic visceral lig stress - liver and lung moving up while organs are being compressed
- skeletal muscle cramp
- irritation of parietal peritoneum - rubbing against each other
respiratory muscle training (2)
less than 80% VO2max - respiratory muscles do not fatigue
greater - they do (e.g. diaphragm)
- fatigue induces reflex vasoconstrictor activity at muscles
- stimulate SNS, E/NE to get vasoconstriction, glycogenolysis - more lactate and oxygen for fatigue
respiratory muscle training:
3 ways
makes the work of breathing harder
- inspiratory flow resistive loading
- voluntary isocapnic hypernea training
- inspiratory endurance threshold loading
pressure
flow x resistance
inspiratory flow resistive loading (3)
adjust the resistance by changing the diameter of orifice
improves strength of respiratory muscles
same about of flow with more resistance to get more pressure - easy to cheat on
voluntary isocapnic hypernea training (2)
voluntarily increased VE for 30 mins, to prevent hypocapnia - drop in PCO2, a device is used to increased the conductive zone (VD)
improve endurance capacity of respiratory muscles - mostly inspiratory, maybe expiratory
inspiratory endurance threshold loading
users must create enough negative pressure to overcome the pressure setting of the device in order to initiate inspiration
improves strength of respiratory muscles - hypocapnia - light headed - increased capacity of conductive zone
reduced inspiratory muscle fatigue
increased strength, power, and endurance
performance effectiveness of submaximal exercise due to respiratory muscle training
some but not all studies - decreased VE, decreased VO2, decreased lactate - maybe a result of attenuated reflex vasoconstrictor activity
results of respiratory muscle training (2)
reduced dyspnea and ratings of perceived exertion
no improvement in VO2max
decreased RPE
perform and feel better -
why do carbs make you feel better
stimulates the reward centre
how to test fatigue on muscle
EMG on muscle
controlled frequency breathing training (4)
restrict the number of breathes to train respiratory muscles
- swimmers - hypoxic workouts - breath/7-12 strokes
- slight decrease in VO2 despite compensatory increase in VT and oxygen extraction
- acute training with controlled frequency training increases inspiratory muscle fatigue
is controlled frequency breathing training effective?
no clear evidence of improved performance - but high intensity effect for low intensity training
concerns with controlled frequency breathing technique
induces hypocapnia - slow down HR and cause headaches, increased CO2
Respiratory adaptation of lung volumes and capacities
lung volumes are not modified by training
- not usually stressed during maximal exercises
- at VO2max VE is less than maximal voluntary ventilation
maximal voluntary ventilation
volume of air that can be ventilated in one minute
exception for respiratory adaptation
why (2)
swimmers - improved static and dynamic lung volumes relative to land based athletes
- breathe against increased resistance from water
- use restricted breathing pattern with high VT
respiratory adaptation on pulmonary ventilation
decreased VE at submaximal exercise (increased VT and decreased f
- improved efficiency of the CRS and NS
increased VE at maximal exercise (increased VT, increased f)
- increased VO2 requires a greater VE
- increased strength and endurance of respiratory muscle
VT1 and 2 increase to higher workloads
respiratory adaptation of external respiration
generally few improvements in diffusion capacity with training
- slight decrease in A-a PO2 diff at submaximal exercise
- elite swimmers have improved diffusion capacity
respiratory adaptation of internal respiration
potential rightward shift in oxygen dissociation curve
decreased PvCO2 at submax exercise (related to increased ventilator thresholds)
avo2 diff shows no change in children, but increases in young adults except for submax
why are there so few respiratory training adaptations
pulmonary system has a large reserve colume - not stressed to the same extent as the CV and neuromuscular system with training
3 situations where the pulmonary system may from a weak link in the O2 transport system
elite athletes - when VE at VO2 max reaches maximal voluntary ventilation
ind with exercise induced arterial hypoxemia - factors leading to it can be eliminated -
exercise - induced asthma/bronchospasm -
all can be diminished
