Yes Howie thanks for your reply. I have two weeks of recordings now and overall they do make sense. I think also if I do get unprecise measurements one day it will correct itself pretty quickly.
I have looked at one of Bioforce's Finnish competitors testing protocol. It is more rigorous. For example they want you to lay in bed two minutes before starting the measurement and avoid swallowing.
I'm about to return to training after a long sedentary period and started taking HRV readnings one week ago.
This isn't as straight-forward as I hoped it should be. I'm having trouble getting consistent meaningful readings. So far I have measured HRV supine just after waking up. My baseline appear to be around 85. My first real workout in months, a 90 minute sRPE6 mountain walk, brought HRV down to 75 the following day, which was saturday. Red indicator and I didn't exercise that day. On sunday I woke up after sleeping a little bit less than usual, and I felt agitated and nervous because I planned to do strenuous exercise that day. I felt I couldn't relax well while taking the HRV reading, and I got a figure in the 70s. That didn't seem meaningful for me. I meditated for a while, got relaxed, and measured HRV to 91.
Late in the day yesterday I did a heart rate-based workout with kettlebellwings that lasted for more than an hour, sRPE6. Today I would expect HRV to have fallen to just below 80. Straight out of bed I measured it to be - 89! This is even with less sleep than usual.
My heart rate around 60 while taking the readings.
I also do Polar OwnRelax readings at the same time as taking HRV. The figure I get from there vary wildly but the conclusion from it has so far always been "well rested".
I'm not sure what to make of this.
I usually meditate each morning, seated. I might try take readings just after the meditations ends, before moving. That could help remove influence from temporary emotions, though belt moisture might be a problem.
Has anyone else experienced similar problems?