Method and apparatus for assessing acclimatization to environmental conditions and to assess fitness level taking into account the environmental conditions and the level of acclimatization

A wearable electronic device operable to be worn by a user, the device comprising:

• a heart rate sensor configured to generate heart rate information for the user;
• a barometric pressure sensor;
• a memory configured to store training history data for the user, the training history data including VO2max information and per-day altitudes of the wearable electronic device over at least the previous seven days;
• a GPS receiver configured to generate position and speed information for the user;
• a display;
• and
• a processor coupled with the heart rate sensor, the display, the barometric pressure sensor, the GPS receiver, and the memory, the processor configured to:
• determine altitude information of a current day using the barometric pressure sensor,
• acquire the training history data for the user,
• determine a current acclimatization altitude based at least in part on the altitude information of the current day and an acclimatization altitude of a preceding day,
• calculate an altitude correction factor based at least in part on the current acclimatization altitude and the altitude information of the current day,
• calculate a corrected VO2max value based at least in part on the altitude correction factor, the acquired training history data, the speed information for the user, and the heart rate information for the user,
• update the training history data stored in the memory utilizing the corrected VO2max value, the current acclimatization altitude, and the determined altitude information of the current day, and
• cause the display to present the corrected VO2max value and an alert indicating whether the user is ready to exercise at an altitude corresponding to the altitude information of the current day.