Lay down and take a VO2 Max reading. 3 mins. Simple.

How is this done?

Read this published scientific paper by UTH N., SORENSEN H., OVERGAARD K., PEDERSEN PK. (2004) Estimation of VO2max from the ratio between HRmax and HRrest--the Heart Rate Ratio Method. Eur J Appl Physiol. Jan;91(1):111-5.

Note: This is a medical test, and data use to calculate VO2Max is calibrated against the average population.