What endpoint is being used to determine whether a tracker is being worn?

[HannahRND]

Hi,

I am working on a health tracking project.

What endpoint can I use for checking if the trial attendees are consistently wearing the tracker?

I am considering using 'last Sync Time' under 'get Device'. Is it the recommended one?

Or are there other items? Thank!

Hannah

[JohnFitbit · Accepted solution]

Hi @HannahRND,

Welcome to the forums! This is a great question.

We don't have any endpoints that will specifically tell you if a device is being worn. However, if you have Intraday Access on your application, you can use the GET Heart Rate Intraday by Date endpoint with 1sec detail-level to see if heart rate was collected from the user over the course of a 24hr period. You can use this data to confirm if the device was worn when/if heart rate was present for that timestamp.

I hope this helps. Let me know if you have any additional questions!

[HannahRND]

Thanks for your reply John.

After some discussion, we decided to use the element 'lastSyncTime' under 'Get Device' since we saw either 'not wearing tracker' or 'not running Fitbit App' stops sending data to server, whereas what we need is to read data from server. 

Hopeful there will be a 'tracker detection' element in the future which will make my life easier. 😄

Thanks for your help.

Hannah

[bklounge]

Hi @JohnFitbit 

Related question about Intraday API returning Activity (steps) and HR (exercise zones and bpm) data when I wasn't expecting it to return anything. Here's sequence of events: Didn't wear device (Luxe) at all for an entire day, but I did move it (put in backpack, put in trunk of car, drove 500+ miles, removed from backpack, put on shelf). My skin never made contact with device sensors during handling.

I subsequently learned that bumpy roads can generate step activity and that "default heart-rate zones are calculated using your estimated maximum heart rate. Fitbit calculates your maximum heart rate with the common formula of 220 minus your age" which likely explains the source/cause/trigger of Activity (steps) and HR (exercise zones) data.

However, I'm stumped on how to explain Intraday API returning HR (bpm) data. Further confusing things is that the Fitbit app doesn't show a resting heart rate figure (see screenshot below). That makes sense: resting heart rate can't be generated if you're not wearing the device. Thus, it's only logical to assume no bpm data would be returned by Intraday API.

Can you confirm whether Fitbit backfills missing bpm data based on my personal history or common formula for bpms that corresponds to each zone?