Stationary / exercise / spinning bike sync with heartbeat

[bennylh]

Hi

I have charge 4, cadence device, speed sensor device and of course a spinning bike.

If I just use my bike - I get calories burned but without anything about my heartbeat and my weight.

Using spinning excrecise in charge 4 (manually) will not know the speed and the intensity of the bike. 

Using app like strava or something else can know the weight, speed, intensity but doesn't know my heartbeat.

Any suggestion how can I know my exact calories burned? 

Thanks

[Rich_Laue]

Using the Spinning mode on the Charge 4 will get your heart rate recorded by Fitbit. Fitbit looks at the heart rate to determine the intensity of the exercise.