Week 5 Seminar - VO2max

Question 1

What time period should you average your VO2 data for? Do you get different values when averaging over 5, 20, 30, or 60 seconds?

Answer 1

There is no “gold standard” for this, but in the literature values between 20 and 60 seconds can be found.

Shorter averaging intervals can lead to inflated values, due to very short time intervals with high VǚO2 values that have a more pronounced impact.

Single outliers also have a larger impact for smaller time averaging intervals.

Question 2

Which information can we get from VO2 data that could be of interest to athletes?

Answer 2

• RER can be used to estimate substrate oxidation.
• Breathing frequency or tidal volume (the amount of volume for each single breath) can be used to answer questions about exercise-induced asthma.

Question 3

Is a VO2 plateau visible? You can use the plateau criterion of <2 ml/kg/min.

Answer 3

Express your data as “relative VO2” if you use the criterion above. Look for the highest value, and check whether the values found in the minute surrounding it do not change by more than 2 ml/kg/min.

Other criteria found in the literature are based on the absolute VO2 (for example, <150ml/min) – here you would check whether values do not change by more than 150ml/min.

Question 4

RER can be used as a secondary criterion to check whether VO2max has been. Which other secondary criteria could you use to confirm your VO2max?

Answer 4

Cut-off values AT EXHAUSTION can be found for RER values of 1.10, 1.15, or 1.20. Other secondary criteria include a minimum blood lactate concentration at exhaustion, or a percentage of the age predicted maximum heart rate. The latter is a very crude measure:

Age predicted maximum is often calculated as 220-age, so for a 25-year-old person I would expect 195 bpm.