Lab 5 - Exercise (Vo2 Max)

Question 1

What is the name of the bag that air was expired into?

Answer 1

Douglas bag

Question 2

What is the douglas bag experiment used to measure?

Answer 2

Volume of expired gases
Percentage of O2
Percentage of Co2

Question 3

What does the measurements from a douglas bag experiment allow us to calculate?

Answer 3

Ventilation, O2 consumption and CO2 production.

Question 4

What was the total volume of expired air measured in?

Answer 4

L

Question 5

What is the equation for working out ventilation in L.min-1?

Answer 5

Expired gas volume (L) divided by gas collection period (min)

Question 6

What is used to calculate oxygen consumption?

Answer 6

Ventilation
Fractional concentration of O2 in inspired air
Fractional concentration of O2 in the expired air

Ventilation x (FiO2 - FEO2)

Question 7

What is used to calculate carbon dioxide production?

Answer 7

Ventilation
Fractional concentration of CO2 in Expired air
Fractional concentration of CO2 in Inspired air

Ventilation x (FeCO2 - FiCO2)

Question 8

How do you work out Max HR?

Answer 8

208 - (0.7 x age)

Question 9

What is EPOC?

Answer 9

Excess Post Exercise Oxygen Consumption

Question 10

Why is O2 consumption still high in recovery?

Answer 10

Due to EPOC

Question 11

What is the difference between the two equations used to calculate oxygen consumption by the body?

Answer 11

(1) Looks at oxygen extraction from blood in the body (oxygen out of blood)

(2) Looks at oxygen extraction from air in the lungs (Oxygen into blood)

Question 12

When our body is in balance/homeostasis what is the relationship between oxygen extraction from tissues vs lungs?

Answer 12

The are exactly the same

Question 13

What is the RER?

Answer 13

Respiratory exchange ratio (or called the respirtaory quotent).

It is the ratio between oxygen production and oxygen consumption.

Question 14

If R is 0.7 what does it mean?

Answer 14

That there is exclusively fatty acid oxidation

Question 15

If R is 1.0 what does that mean?

Answer 15

That there is exclsuievly carbohydarte metabolism.

Question 16

What causes the RER to exceed 1.0 during exercise?

Answer 16

Hyperventilation meaning that you are breathing out more CO2 than is being produced

Lactic acid production leads to excess H+ and then CO2

Question 17

What is VO2max?

Answer 17

The maximum amount of oxygen the body can utilise.

Question 18

What does our body use oxygen for?

Answer 18

To burn feul in order to produce energy = therefore the more oxygen your body can use, the more energy you can produce.

Question 19

What do people with higher VO2max have lower risk of?

Answer 19

Premature death, cardiovascular disease, chronic conditions such as Type 2 diabetes.

Question 20

What is the highest male and female Vo2max ever recorded?

Answer 20

Male = Oskar S cyclist @ 97.5
Female = Joan B runner @ 78.6

Question 21

What is the lowest resting HR ever recorded?

Answer 21

Daniel Green aged 81 @ 26 bpm

Question 22

What is normal VO2max for male and female?

Answer 22

Male normal is 40-45
Female normla is 30-35

Question 23

If you have a high Vo2max how is oxygen consumption and supply affected?

Answer 23

With a higher Vo2max you can take more oxygen out of each L of blood with increased blood supply due to increased HR.

Question 24

At rest how is MABP mainatained within a small range?

Answer 24

Baroreceptor reflex
- baroreceptors in arteries detect BP changes and send signals to the brainstem.

The brainstem then adjusts the blance between the two nervous systems.

PSNS (resting state) = lowers HR, SV and TPR which all reduce MABP.

SNS (active state) = increases HR, SV and TPR increasing MABP.

Question 25

How is the baroreceptor reflex adjusted during exercise?

Answer 25

During exercise your muscles need more oxygen so we need to allow an increase in MABP.

Therefore a central comand sends a signal to inhibt the baroreceptove cells so that there is no baroreceptor input.

Instead skeletal muscle contraction activates exercise pressor relex which causes an increase in sympathetic nerve activity.

= Increase in MABP.

Question 26

Other than increase CO how else can the vascular system increase O2 delviery to active muscles?

Answer 26

Vasodilation (which decreases TPR)

Question 27

What is the effect of vasodilation on TPR?

Answer 27

Decreases it

Question 28

How does vasodilation occur?

Answer 28

Functional sympatholysis and B-adrenergic receptors

Question 29

What is functional sympatholysis?

Answer 29

Functional sympatholysis refers to the ability of the active muscles to override the normal vasoconstriction caused by sympathetic nerve activity. This is achieved through local factors in the skeletal muscles, like the release of nitric oxide (NO), CO2, H+ and adenosine and the decrease in O2 which cause vasodilation.

This selective “relaxation” of blood vessels in the active muscles helps direct more blood to them while allowing the rest of the body’s blood vessels to stay constricted to maintain overall blood pressure.

Question 30

Does EPO injecting change oxygen requirements at rest?

Answer 30

No

Question 31

What are adverse effects of an increased haematocrit ratio?

Answer 31

Increase blood viscosity (thickness of blood) therefore there is an increased risk of coagulation (clotting) and more work for the heart.

Question 32

When is an athlete who EPO injects at greatest risk?

Answer 32

The night after a big event - ebcause dehydrated and low resting HR when sleeping (= very thick and slow moving blood)