Use Resting Heart Rate formula instead of Max Heart Rate

[Mjshuster]

Since the RHR is supposed to be more accurate than the MHR, why not use it. The device has already captured our Resting Heart Rate, so why not run it through the formula and base the daily heart rate graph on the RHR?

[JohnnyRow]

The formulas I have seen that use RHR also require max heart rate.

What they do is just base heart rate zones on how far your heart rate is up as a % of difference between RHR and max HR.

But are you thinking of some other formulas and measurements?

[Mjshuster]

No. I am thinking of the Karvonen formula. I was led to believe that there’d be a difference between (220-age) and the Karvonen formula, but in my case, they are identical. Therefore, the Fitbit formula is just fine for me. I spoke too soon.

[MrMarv]

@Mjshuster and @JohnnyRow - 

Came across this thread while searching for a post on another thread...

For most devices and all devices prior to the Charge 4, the Traditional method of flat percentages of Max HR (50, 70 and 85%) for the three zones were used.

The Karvonen formula is what we have recently seen referred to as the "Heart Rate Reserve" formula here on the boards. The "new" formula used by the Charge 4 and now the Ionic and Versa family of devices.

For me, the numbers changed in the following way: