About heart rate intraday with 1 seconds scale

[Puntawat_Brain]

Now I'm using the API : https://api.fitbit.com/1/user/-/activities/heart/date/today/1d/1sec.json

for getting the heart rate in 1seconds resolution. But what've got is about 10-15 seconds gap between each timestamp of heart rate. So how can i interpret the missing gap? Is the missing gap means holding the recent value until the heart rate have change clearly? 

Thank you for answer my question

[Gondwana · Accepted solution]

That's fairly normal. When not in 'Exercise' mode, the watch only records heart rate every 5 to 15 seconds. In 'Exercise' mode, that drops to 1 to 3 seconds.

I'd interpret the values as snapshots (samples), not changes. If you really need intermediate values, interpolate. Just bear in mind that the data does not actually imply anything about such intermediate values (other than that they should be plausible given the values around them).

[Puntawat_Brain]

So How can i change into exercise mode or fitbit will decide by heart rate and accelerometor which periods are in exercise

[Gondwana]

Tell your watch you're going for a run/walk/workout, etc. Details depend on the type of watch. Ionic and Versa have an "exercise" app, but most other Fitbits have an equivalent.

I don't know if the auto-detect mechanism ups the sampling rate.

[Puntawat_Brain]

Yep, I see. I've try on my charge HR to change to exercise mode. do you know how long can i turn on the exercise mode? I need the details for my heart rate. Is it possible to open up to 7 or 8 hours ?

[Gondwana]

Sorry; no, I don't know. I'd imagine that having the sensor do more work would have an impact on battery life, but if you have the option to let the screen go off while you exercise, I think the impact would be small.

[Puntawat_Brain]

For exercise mode on Fitbit Charge HR, the screen will go off all the time. The screen will open when you push a button or move your arm into a position of look a time at its screen. Thank you very much for your help. Will try for recording in long time interval. Thank you 🙂