Aerobic Performance

Question 1

What advance in technology in the 1970s allowed the invention the ramp incremental test to determine maximal oxygen uptake?

Answer 1

Breath-by-breath gas analysers

Question 2

What is the problem with the use of the ‘oxygen uptake peak’ as opposed to maximal oxygen uptake?

Answer 2

‘Peak’ does not discriminate between subjects who have stopped exercising for other reasons not related to them attaining their true maximal oxygen uptake

Question 3

What is the GE threshold an indirect measure of?

Answer 3

Lactate threshold

Question 4

What does GE threshold strongly predict?

Answer 4

Performance in endurance events lasting longer than 10 minutes

Question 5

What is a VO2 peak when talking about maximal O2 uptake?

Answer 5

When a plateau in VO2 is absent during a ramp test.

Possible due to ‘insufficient effort’.

Question 6

What is suggested to check the validity of the VO2 max?

Answer 6

Carry out a verification bout.

In the form of a high intensity bout of exercise a short time after the ramp incremental test.

Question 7

Define the lactate threshold

Answer 7

Metabolic rate at which the blood lactate conc begins to incr above baseline values

Question 8

What does the bicarbonate buffering of lactic acidosis result in?

Answer 8

Production of non-metabolic CO2 + ⬆️ VCO2 measured at the mouth

Question 9

How can the GE threshold be determined?

Answer 9

Using the ‘V-slope’ method from data collected during the ramp test to exhaustion.

Question 10

What is the most popular means of establishing the GE threshold + VO2 max?

Answer 10

Ramp incremental test to exhaustion.

Question 11

When preparing the incremental ramp test, how might one reduce the possibility of premature fatigue?

Answer 11

By setting the ramp rate to result in exhaustion in 10-15 minutes.

In young, healthy subjects, usually 25-30W/min

Question 12

What is the ‘ramp rate’?

Answer 12

The rate of increase in external workload

Question 13

How long should it take to complete the ramp incremental test?

Answer 13

10-15 mins

Question 14

Why do we use a verification bout in the ramp incremental tests?

Answer 14

To validate the max O2 uptake that was determined in the ramp test.

Particularly useful if a plateau in oxygen uptake was NOT observed at the end of the ramp test.

Question 15

What do we expect to see if the subject gave a truly maximal effort in the ramp incremental test?

Answer 15

Agreement between the end O2 uptake values between the 2 tests.

(The ramp incremental test + the verification bout test)

Question 16

What proportion of participants exhibit a plateau in their oxygen uptake during a ramp incremental test?

Answer 16

Day et al (2003) found that 40% of their participants exhibited a plateau.

Question 17

What does it mean if the oxygen uptake at the end of a verification bout is higher than that at the end of the ramp incremental test?

Answer 17

Participant did NOT attain their Max O2 uptake during ramp incremental test.

Test should either be repeated, or the higher value from the verification bout recorded as max value.

Question 18

What data do we need to calculate the gas exchange threshold?

Answer 18

O2 uptake + CO2 production

Question 19

Why do we see a change in the rate of carbon dioxide measured at the mouth as exercise intensity increased?

Answer 19

Bicarbonate buffering of hydrogen ions that are being produced during anaerobic glycolysis.

Question 20

Why do we need to deduct 40s of data (or 20W; 2/3 the ramp rate) when we make our calculation of the gas exchange threshold?

Answer 20

It is important to account for the fact that what we observing in our gas exchange data at a given time in the ramp test is reflective of something that occurred slightly earlier. In the same way that oxygen uptake does not immediately adjust to the new demand in a ‘step’ test, it also does not immediately adjust during ramp incremental testing. Think of a ramp test as a bunch of tiny steps, where the measures we are taking are always slightly behind as the body is in a constant state of adjustment.

Question 21

Why would we be interested in determining the gas exchange threshold?

Answer 21

1. Dictates % VO2max (and speed) that can be sustained for endurance exercise
2. Provides measure of endurance capacity or functional work capacity which is independent of VO2max
3. Predicts performance in events of >10 min duration
4. Mechanisms of fatigue may differ above + below the LT
5. Its measurement may be important in the prescription of optimal training

Question 21

Define aerobic energy

Answer 21

ATP generating reactions where O2 is the final e- acceptor in the ETC.

Question 22

What happens if O2 availability is limited?

Answer 22

• e- flow reduces + ‘backs up’ the ETC
• NADH + H+/FADH2 accumulate
• Flux through Krebs cycle is reduced

Question 23

How do we continue to exercise if O2 availability is limited?

Answer 23

By incr. our anaerobic energy turnover.

⬆️ amount of pyruvate being reduced to lactate = ⬇️ pH = ⬇️ muscle function = fatigue.

Question 24

Define VO2 max

Answer 24

Max rate that ATP can be synthesised aerobically

Question 25

What equation is used to calculate VO2 max?

Answer 25

Fick equation

VO2 MAX = Qmax x a-VO2 diff max

Question 26

In the Fick equation, how is the Qmax calculated?

Answer 26

SV max x HR max

Question 27

In the Fick equation, how is a-VO2 diff max calculated?

Answer 27

CaO2 - CvO2

a = arterial 
v = venous

Question 28

What does it refer to when we talk about aerobic aspects in regards to central?

Answer 28

Pulmonary diff capacity

Max CO

O2 carrying capacity of blood

Question 29

What does it refer to when we talk about aerobic aspects in regards to peripheral?

Answer 29

Extraction/utilisation of delivered O2 at the muscle.