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. For help watch this video https://youtu.be/lV5oyoW213A or contact me on https://twitter.com/ZoneTrainingApp/ for help. Note: This is not a medical test, and data use to calculate VO2Max is calibrated against the average population. Medical disclaimer: The medical/health information is provided for general informational and educational purposes only and is not a substitute for professional advice. Accordingly, before taking any actions based upon such information, we encourage you to consult with the appropriate professionals. We do not provide any kind of medical/health advice. THE USE OR RELIANCE OF ANY INFORMATION CONTAINED ON OUR MOBILE APPLICATION IS SOLELY AT YOUR OWN RISK.