I do an estimation of max HR, with different methods. This is really just an estimation. For resting HR, which can also be used to get the Zones if you select Karvonen method, I use an export from Apples HealthKit. I currently do the average of the last 7 days. Not sure if Apple does an estimate for this value, too?
Oh how cute, estimates. 220-age is so accurate lol. Just a joke to even talk about this nonsense, it's completely unhelpful in all manner. I just set myself an arbitrary goal for the run (say 160bpm over an hour, which is something i'm working towards so i may be say averaging 165 currently) and try to attain that progresively each week. No idea what zone that is, don't care. If it's currently 'zone 4' so what? It will eventually become 'zone 2'. If i spend all my time doing 'zone 2' at worst i'll be wasting time, at best, i'll be spinning my wheels.
