I retested the Own Index/O2Max on my Polar i810 and came up this time with 45 - as high as it has ever been. I was pretty relaxed when I took it, but the average of 43 is good. Tops for my age group.
The i810 projects a maximum heart rate of 146 or so, down from the 168 or so from just a year or so ago. I thought this was too low. On this morning ride I got up to 165, so I was right. I'm leaving the set maximum at 160 in the Garmin Vivoactive though.
That leads to these five heart rate zones.
50% - 80-95
60% - 96-111
70% - 112-127
80% - 128-143
90% - 144-159
100% - 160
More accurately, based on 165:
50% - 83-98
60% - 99-115
70% - 116-131
80% - 132-148
90% - 149-164
100% - 165
Today, I was in zone 2 on the uphill of the GoWalk group's Thursday walk.
That Monday, I topped out at 165 at the top of K2.
My Monday rides put me in 2-3 a lot of the time, with a couple of 4's and on occasion, a 5. No 5 on the Wednesday ride.
An average HR of 110 on that Monday would equate to zone 2 on both sets above. Fatburner.