Based on the Karvonen method your heart rates can be divided into 5 – 7 zones. Zone 1 is your recovery zone (up to the heart rate of fast walking), zones 2 – 4 refer to your easy, moderate and intense duration zones. The high-end of the intense duration zone is named ‘threshold’. This is a heart rate you can typically train on for 15-60 minutes. Above threshold, you are training in ‘anaerobic’ zones where you have a lack of oxygen. So you can only train for a few minutes in those zones. As long as your threshold is filled in correctly, the anaerobic zones are not so important. Be aware that selecting a too low threshold value is bad for nutrition planning, since this causes that we will overestimate your exercise level. The most accurate method to know your zones is doing a VO2Max test at a physiologist. Alternatively you can fill in that you don’t know your zones. Our system willthen estimate your zones. Please be aware that unrealistic heart rate zone values will be adjusted automatically to avoid incorrect nutrition plans.