The 220 rule is so vague it's pretty much useless mate
There are various self tests you can do to measure your max heart rate, no matter the test they're all brutal and i wouldn't recommend attempting unless you've had a heart stress test and are reasonably fit
I used to do the max heart rate and VO2 tests when i was younger
Honestly i think they're nonsense
Even when i was cycling competitively and interval training i still found the the max heart rate test to be only a rough idea
Eventually through experience i found what heart rate i could maintain during a MTB race or a 25 mile time trial
I found this more useful than the max test
Unfitter you are, easier it easy to keep HR up so to speak.
Completely disagree
Max heart rate is in no way any gauge of someones fitness
Low fitness level means the HR will be higher more of the time during the exercise. Fitter you are, better the recovery, so HR goes more up and down, rather than keep at higher level.
Again, i disagree
1/ Heart rate is different for all of us
During a 25 mile time trial in my late 20's i would peak at 225bpm
My mate and training partner would barely see 180bpm in the same time trial
We would both finish at roughly the same times
2/ Another thing to consider is fatigue, sleep, nutrients, even weather (temperature mainly)
For me these hughley affect both my average and max heart rates during exercise
3/ I've been reasonably fit (just under 1 hour on a 25 mile time trial), although the way through to really really unfit to the point where i needed to stop for a breather walking up 2 flights of stairs
I've also be using heart rate monitors and keeping training notes since the mid 90's
My advice is to wear your heart rate monitor a fair bit during various exercises
You'll then get an idea of what your average heart rate is and how this corresponds to perceived effort
If you want to try interval training i think a heart rate monitor is pointless
Just go as hard as you can for the intervals
After years of monitoring my heart rate i'm now getting to the point where i believe it's pretty pointless
These days if i'm not on-call i won't take any electronics with me
Best things i've found about using HRM's for over 25 years is they're good for measuring fatigue
If my resting heart rate is high i know i'm either coming down with something, am stressed, didn't sleep well or i'm fatigued
Tricky thing is deciding if i'm stressed (exercise helps me with this) or ill (tends to aggravate the illness)
My fitness level doesn't seem to make much of a difference to my average heart rate
Of course my perceived effort is higher the fitter i get as my body is working more efficiently and i'm more able to maintain the discomfort, but my average heart rate stays around the same
Biggest difference i've noticed is my age really affects my average heart rate
2010 my average heart rate on a local run was 176bpm
2020 i'd struggle to see that as my max
This with the same sort of physical effort on the exact same run