CERTAIN ACTIVITIES CAN AFFECT HEART RATE PERFORMANCE
False Heart Rate Detection
Changes in blood volume aren't always caused by changes in heart rate. Your vascular system is
like a balloon, so movement of your body or flexing of large muscle groups can affect the level
of blood volume in the wrist area and make it more challenging to accurately detect heart rate
among the presence of other signals that have a much larger magnitude and that change more
dynamically.
In the following example the watch initially detected and locked onto the runner's pulse,
but around 20 minutes in it locked to their running cadence:
Why does this happen?
In some cases there isn't much blood in the tissue on the back of the wrist. This issue is
common when it is cold outside or early in a workout before your blood really starts pumping.
How can I prevent this from occurring?
When you plan to workout, warm up a bit before starting the activity. In addition to this, make
sure you are properly wearing the watch. Tips on fit are described in the next section.
