I have been slowly ramping up my exercise - cardio first with my long walks and time on my elliptical and my rowing machine. After a treadmill test, I was provided with a target heart rate range that I should maintain for these exercises. And I had trouble with measuring the heart rate.
I use a Fitbit Versa 2 as my primary tracker and I found while using it, the heart rate was all over the place. It would suddenly shoot up. And then go down. It was not dependable at all. I also used the built-in heart rate monitor on my Elliptical and it was higher by a factor of 10-15% than the Fitbit, leading to more confusion.
So, for the next few days, I used both my Fitbit and my Apple Watch SE both during my walks and my elliptical usage. But, no go. These did not agree with each other. More so, they were not consistently different from each other, but inconsistently different varying in the range of differences with each other.
Finally, I had a breakthrough today. Had my first Cardio rehab session at the hospital and was able to calibrate the devices against the Elliptical at the hospital. I could confirm that the Apple Watch SE and the Elliptical both agreed with the heart rate all the time. And the Fitbit was all over the place. So, I had my answer on which device to depend upon. Until I hit the next roadblock.
And hopefully from here, a sustainable cardio training program will emerge. Day after day. Week after week. Month after month, and year after year. And very soon, adding the strength training regimen starts. And for one it is a major change for me, as I have never ever wait trained in my whole life. But, I guess, it is never too late to start - with one more change.