How are the heart rate zones divided while running with the watch?

The heart rate zones of the watch can be divided into Relaxed,Light,Intensive,Aerobic,Anaerobic, VO2 max.

For example, if a user is 25 years old, the maximum heart rate = 220 - current age = 220 - 25 = 195, and if the heart rate value measured by the watch lies between 50% - 60% of the maximum heart rate, the watch will take it as the light zone. If it lies between 60% - 70%, it's the intensive zone, and so forth, and this is the way we determine how to divide the zones.