Vivoactive heartrate by heart rate strap

It uses the chest strap if it is connected, not wrist heart rate.

It will use the strap if you are recording an activity.  If not, it will disconnect from the strap after a short time.

Thank you!! Great, because my wrist heart rate doens't messure acurate.

Thank you!! Great, because my wrist heart rate doens't messure acurate.

Of course the wrist sensor doesn't measure accurate at all. A classic business policy in order to be forced and buy additional accessories so as to increase business profits... 

vannidejo said:

When I run with my Vivoactive 4S and my heart rate strap, and I made the connection with the strap by the sensor possibility, will it then automatically measure my heartrate by the strap or does it still measure my wrist heart rate?

you can make sure that your HR is measured by a chest strap if check your optical HR sensor, it should remain inactive during started activity and  if chest strap is connected.

I don't think this is true. I've got a (non Garmin) chest strap which works fine (provided I don't wear certain tops) and which I regard as reliable. However, I occasionally forget this on morning runs and I forgot it at a parkrun last weekend. Most of the time, including the parkrun, wrist HR is fine. *Sometimes* it's clearly wrong, and it takes longer to get to a high reading. So it's buggier and a less reliable method, but not, IMO, intentionally so. I had a similar problem with wrist HR when I had a Fitbit (it would jump to stupidly high, and stay there after going up a hill, for example) and they don't even sell chest straps, so I can't see the business motivation there.

DaveInWatford said:

I had a similar problem with wrist HR when I had a Fitbit (it would jump to stupidly high, and stay there after going up a hill, for example) and they don't even sell chest straps, so I can't see the business motivation there.

true, it's not a business model but limitation of the current technology as an optical HR can't poll your heart rate fast enough to get pulse which you have in the current moment, that's why sometimes we may see high pulse after activity staying longer than if we would measure with a chest strap

I don't think it's a poll rate issue, but rather a matter of noisy signal. The algorithm must decide what is the most likely value based on recent values and knowledge about what you are doing. Sometimes the algorithm homes in on cadence instead of heart rate.