HR Zones calculation methods
I have a few questions regarding the 2x20 and other methodologies:
The 2x20 method generates a linear line. Is “effort” really linear? Other methods suggest none liners graphs (or is it really related to Exertion). The non-linear line is taking into account a Factor increases with effort.
Other methodologies do not use same percentages range for Zones. For example, a recovery Zone is much larger than the Aerobic or Lactate Threshold.
Are the Zones really generic or individuals may have various Zones. Like the MHR, the Zone ranges can vary.
How can I make the transition/translation between these methods?