L20 Flashcards
what is the major fueling pathway for our exercising
skeletal muscles
Oxidative
phosphorylation
when do we use oxidative phosphorylation
when we excersize over 2 min
We need to get O2 to the muscles which diffused into the blood in the lungs then it goes to the mussels where CO2 is produced and then that cose back to the lungs where it is expelled. For all of this to happen we need…. what
a healthy respiratory system
3 main goals of respiratory
system during exercise
Ensure that partial pressure of O2 (PaO2) in our arteries is well
maintained to allow adequate O2 supply to exercising muscles
To eliminate metabolic and nonmetabolic CO2 to maintain the partial pressure of CO2 (PaCO2)
in our arteries
To assist in the buffering of
metabolic acids produced
during high intensity exercise
at sea level what is the PP of O2
159 mmHg
at sea level the PP of O2 = 159mmHg, what is it when it reaches the alveoli
105mmHg
what is the process in which O2 is consumed by the muscles
oxidative poshorilation
at rest what % of O2 do we use (because of oxidative phosporilation)
This drops the conc of O2 down from 100 to 40 therefore at resu we use about 60 of O2
at rest how many mL of O2 do you have per 100mL of blood
20 mL
at rest how many mL of O2 will the muscles extract from the blood
4-5mL
when we are excersizing this chages
what are the sources of CO2
Metabolic (oxidative phosporilasiatin)
• Glucose + 6O2 → 30 ATP
+ 6CO2 +6H2O
• Palmitate (FFA) + 23O2 → 108ATP + 16 CO2
Non-metabolic
• H+ + HCO3 → H2CO3 →
CO2 + H2O
H+ ions get buffered by bicarbonate which is in the muscles but when H+ binds it produces CO2
what is tidal volume
definition and velue
Tidal volume is the amount of air breathed in with each normal breath. The average tidal volume is 0.5 litres (500 ml).
how do you increase ventilation
(1) Increase tidal volume
(2) Increase breathing frequency
what is the relative increse in ventilation rate, tidal volume and breathing frequency that occurs because of excersize
VE = 32x
VT = 8x
f = 4x
The increase in ventilation during exercise
is controlled by what
both neural and humoral
(chemical) pathways.
when anticipating to excerise you breathe quicker to prep your for that extra O2 that you will need.
what is this done by
This is done by the brain
The first few minutes of excersize feel really hard and then after awhile its not so bad. why is this
This is because the neural response steals down and the chemical response takes control
how does work in the muscles lead to an increase in ventilation rate
Lactate that is produced causes an increase in H+ which increases the acidity levels of the blood
This is buffered by hydrogen carbonate. This H+ leads to the formation of CO2. this CO2 then diffuses into the CSF where it gets converted back into H+ ions. It then acts on the central chemoreceptor to tell the lungs to increase the respiration rate as CO2 levels are getting too high
what is the best way to breath to maximise O2 intake and CO2 output
deep breath in (O2)
sharp breath out (CO2)
ATP generation is dependent on 3 things. what are these
in terms of exercise
Intensity of excersize
Duration of excersize
How fit are you
what does fitness have to do with excerise (3 points)
The fitter you are the longer ti takes for you to get to the point where you have to use your aneraobic system
The more fit you areobic system is the longer and the faster you can go
The longer you can preform in the anerobic zone the stronger you are
describe the % of energy production/time graph
the graph with all the different energy systems
NOTE that all of the energy systems are active all the time it is ject that in some phases some are more active then others
0-2 sec you use all of the ATP stores therefore % of energy production decreases
0-2 sec ATP creatine phosphate increases % of energy production and the 2-10 sec the % decreases
0-10 sec the % of energy produced from the lactic acid system slowly increases and then decreases from 10 sec to 2 min
the airobic system is fairly constant with but is the main form after exercising for longer then 2 min
main energy system 0-2 sec = ATP stores 2-10 = ATP creatine phosphate system 10 sec - 2 min = lactic acid system 2 min onwards = aerobic system
what is the ventilation vs workload (intensity) relationship
As work load increases so des our ventilation
The harder you are going the faster you are breathing and the more tidal volume you will try and recruit
what is another name for the functional threshold power
anaerobic threshold
what is the functional threshold
The maximum intensity an athlete can hold without accumulation of lactate, or the fatigue that goes along with that phenomenon
why did the term anaerobic threshold lose its popularity
The term anaerobic theshold loss its popularity when it became apparent that there is no point in time where O2 is simply not used. This is because at all times both systems are being used it is just that at different times one system is dominating the other
what is functional theshold power dependent on
- Aerobic system : how quickly lactate can be removed
* Anaerobic system: how much lactate is produced
when de we start to rely on anerobic systems
When we satrt to rely on the anerobic system it is because we are unable to get sufficent O2 to the muscles in order to sustain the excerise aerobically
Anerobic produces more …..
latate
what is the latate threshold
The latate threshold is when the intensity get even higher than the anerobic threshold
This happens when we run out of energy stores and we have to stop and we have to slow down and go back to our areobic system
what is VO2 max
the point at which we have to stop (or slow down)
this is the point where the max amount of O2 is getting to the muscles
what does it mean if you increase your aerobic fitness
The more aerobically fit you are the further along the exercise intensity you can maintain before you switch over to the anaerobic system
how long can you rely on your anaerobic system
Anaerobic systems is will trained then you might be able to use this system for 2 min before you run out of energy stores. Untrained people is less then 1 min
describe the graph that describes functional thresholds power
HR, VO2 and VCO2 all increase linearly
lactate increases exponentially. slight increase at aerobic threshold and sharp increase at anaerobic threshold
what is the unit for VO2 max
max volume of oxygen a person can use
mL/Kg/min
how do you measure VO2 max
To mesure VO2 max you push an athlete until the anaerobic system takes over and then keep pushing until they have to go back to aerobic
Which of the following sports in an anaerobic activity? • Baseball • Marathon running • Weightlifting • 1500m running
weightlifting
