I am not sure, while the values obtained this way might require calibration, it sounds like very controlled conditions to me. The exercise should bring your body into a very controlled state, beyond the physical load very relaxed. So after a short rest, this should be a good time to get reliable readings. But I am not a doctor.

Yeah, agreeed, and I think the BP is a bit lower because I'm warmed up and then rested a bit. My worst BP is in the mornings after getting up and sitting and drinking coffee.

I've been using Google Fit to track my blood pressure over time. I've been measuring every other day. The charts really are helpful.

The biggest correlation with my blood pressure is how regular my sleep is. Once I started militantly waking and sleeping on a set schedule, the numbers came down. They seem to spike for a few days if my sleep gets messed up badly somehow.

I also have been trying to standardize my measurement: same time of day, after sitting quietly alone for five minutes.