Your device displays heat and altitude corrected VO2 max. values when you are acclimating to high heat environemnts or high altitude.
Heat and Altitude Performance Acclimation
Environmental factors such as high temperature and altitude impact your training and performance. For example, high altitude training can have a positive impact on your fitness, but you may notice a temporary VO2 max. decline while exposed to high altitudes. Your fēnix® device provides acclimation notifications and corrections to your VO2 max. estimate and training status when the temperature is above 22ºC (72ºF) and when the altitude is above 800 m (2625 ft.). You can keep track of your heat and altitude acclimation in the training status widget.
NOTE:The heat acclimation feature is available only for GPS activities and requires weather data from your connected smartphone. Full acclimation takes a minimum of 4 training days.
