A fight - or - flight stress response, mediated by the sympathetic nervous system, creates
almost instantaneous physical reactions, including increased
heart rate and blood pressure,
changes in attention, memory, and other bodily functions.
I found that the Huawei tended to be 5 — 10 seconds behind the Garmin when it came to displaying
changes in my
heart rate, but once it caught up it was
almost always within five beats per minute, and more often it stayed within two.