Adaptations to endurance training

Question 1

VE?

Answer 1

Minute ventilation

Question 2

VO2?

Answer 2

Rate of oxygen uptake by the lungs.

Question 3

QO2?

Answer 3

Rate of oxygen consumed by cells.

Question 4

VCO2?

Answer 4

Rate of carbon dioxide output by lungs.

Question 5

QCO2?

Answer 5

Rate of carbon dioxide production by cells.

Question 6

R?

Answer 6

Respiratory exchange ratio (VCO2/VO2)

Question 7

RQ?

Answer 7

Metabolic quotient (QCO2/QO2)

Question 8

What requirements are there of normal gas exchange between muscle and the environment?

Answer 8

1) Effective lungs and chest bellows.
2) Effective pulmonary circulation so regional blood flow is matched to appropriate ventilation.
3) Heart capable of pumping the quantity of oxygenated blood necessary to to sustain tissue energy exchange.
4) Effective system of BV that can selectively distribute BF to match tissue gas exchange requirements of working muscles.
5) BF with an adequate Hb concentration
6) Respiratory control mechanisms capable of regulating arterial blood gas tensions and pH.

Question 9

How do you measure O2 consumption during exercise.

Answer 9

Mouth piece - valve allows air to be taken in from atmosphere and also allows expired air to go into a Douglas bag. Measure concentrations and volumes.
Work done on ergometer - can be controlled. Set braking resistance and pedal frequency - allows power output (watts) to be set.
To calculate VO2 and VCO2 we also need to know - barometric pressure and temperature.

Question 10

Explain the relationship with low exercise intensity and VE, VO2 and VCO2.

Answer 10

At low intensities - all rise linearly with increasing power output.

Question 11

What is the anaerobic/lactate threshold?

Answer 11

HIghest exercise intensity/O2 uptake that is not associated with an elevation in blood lactate concentrations above the pre exercise intensity.

Question 12

What happens to LA as work intensity increases?

Answer 12

As work rate increases, lactic acid is buffered by sodium bicarbonate producing CO2.
THis Co2 must be eliminated to prevent pCO2 rising.
Increased pCO2 is the driving force for increased ventilation.
VCO2 and VE increase more than VO2

Question 13

What happens as work rate increases to max?

Answer 13

[H+] from HCO3w- decrease and stimulates carotid bodies to increase VE even more. This a respiratory compensation for a metabolic acidosis.

Question 14

What changes happen to the CV system during dynamic exercise?

Answer 14

QO2, HR, SV, MAP all increase.

TPR decreases as BV in legs dilate to allow O2 in.

Question 15

Explain how the pulmonary system may limit the body’s ability to utilise O2 (Limit VO2 max)

Answer 15

Limiting in high altitudes and those with COPD or asthma.

We know this because VO2 max can increase when increase when taking in O2 enriched air.

Question 16

Explain how oxygen carrying capacity may limit the body’s ability to utilise O2 (Limit VO2 max)

Answer 16

Blood doping increases VO2 max.
Erythropoietin (EPO) - genetically engineered version of natural hormone produced by kidneys to stimulate RBC production.

Question 17

What happens is someone has a mutated EPO receptor?

Answer 17

Always on! EPO always being produced.

Question 18

Explain how cardiac output may limit the body’s ability to utilise O2 (Limit VO2 max)

Answer 18

Max CO and man O2 uptake correlate suggesting that the size of the heart or max SV is key in determining max O2 uptake.

Shown if you isolate and just train one knee - O2 uptake is 2-3 x higher in isolated knee than when working the whole body.

Question 19

What is the Fick equation?

Answer 19

VO2 = CO x (CaO2 - CvO2).

Question 20

Define training.

Answer 20

TO cause biological adaptations to improve performance.

Question 21

What are 4 other the general principles of training?

Answer 21

Overload
Specificity
Individuality
Reversibility

Question 22

What is the highest level of fitness determined by?

Answer 22

VO2 max

Question 23

With endurance training you get an elevated CO/SV - why?

Answer 23

Improved diastolic filling and increased EDV…
Expanded plasma volume…increased venous return…prolonged diastole…enlargement of ventricular volume…greater ventricular complience.

FRANK STARLING

Question 24

What 4 other adaptations does sub-max training cause?

Answer 24

Decreased vasopressin and renin (vasoconstrictors)
Decrease relative VO2.
Decreased Respiratory Exchange Ratio.
Increase exercise intensity before OBLA.

Question 25

What happens to mitochondria with exercise?

Answer 25

increase in number and sixe and increase the mitochondrial enzymes.

Question 26

What happens to the fuel source after a period of endurance training.

Answer 26

Total energy expenditure is the same but fat combustion increases and CHO and glycogen are saved.

Question 27

What is PGC-1?

Answer 27

The master regulator of mitochondrial biogenesis and also regulates other slow genes suchas slow troponin and slow myosin.

Question 28

What stimulates PGC-1

Answer 28

AMP activated kinase
Calcium:calmodulin activated kinase
p38 MAPK increases the phosphorylation of PGC-1

Question 29

What changes occur to BF and BVs with endurance training?

Answer 29

Increase capillary density through angiogensis.
Increase transient time (blood flows through more slowly - therefore more time for O2 to diffuse.
Increases O2 extraction.

Question 30

Can fibre types convert?

Answer 30

IIX - IIA - YES!

IIA - I - VERY HARD!!