Initially i used to train to HR and then I did a MAP test to determine my zones
This was a while ago now but this was the result
which gave me these zones
Zone 1 = <125 beats per minute.
Zone 2 = 125-144 bpm
Zone 3 = 144-165 bpm
Zone 4 = 165-178 bpm
Zone 5 = 178 + bpm
Once i’d done about 6 months of trainnig i redid the test and my zones had changed
Level 1 = <140
Level 2 = 140 – 158
Level 3 = 158- 172
Level 4 = 172 – 178
Zone 5 = 178 +
essentially my zone 2 area was really really crap. i was only utilising 43% of energy from fat.