The party line appears to be that if you use both you get DOUBLE COUNTING so you should use one or the other. However, the reason one would like to actually use both is that we often forget the FitBit, but sometimes have the darn phone and so won't lose the steps if both are active.
What would we ideally want to see happen? and does it?
Ideally what you would want to have happen is that whatever FitBit unit you use takes priority over data collected from other devices (Mobile Track) WHEN the data occurs at the SAME time. This requires that your FitBit and your smart phone device actually have the same time (which is a pretty good bet if they are linked and synced at least once a day). The Mobile Track then fills in data when the FitBit is forgotten at home for dinner or some other event and you don't lose the steps. This makes sense as the program clearly knows when data is being entered for the same time (as happens when you put in a new activity) and will only keep one set of data not two (usually the new data you put in).
What actually happens?
Well here is what I seem to have observed, but I'm wondering if others have seen different results.
1. For Apple's Health program the steps seem to be added as extra and there is sometimes double counting. I say sometimes, because I have almost ZERO confidence in Apple Health and have NOT found it to be very reliable and so I can't tell for sure but have the impression that it tends to double count. You would think the app would realize data is coming for steps from TWO different devices at the same time and so one set of data should take priority.
2. For FitBit App. If there is double counting on the FitBit App when I run 3 miles (approximately 7K steps) I should on a regular basis hit 10K steps right off the bat. This NEVER happens. So without further testing, I am left with the impression that the FitBit data overides the iPhone's data when the data points are the same. It is possible the iPhone data overwrites, but that is NOT my impression. I have not fully tested and compared to verify.
3. Missing Data. My impression is that if the FitBit is left at home and I still have the iPhone that simply doing a sync to mobile track adds in the data that was missing (very nice). I don't have the perception that the count is automatically doubled. It is pretty clear to me that the app is processing the data and I do see the numbers go up and down, but finally settle usually on something that makes sense.
Does anyone have any other RELIABLE testing or information on this? I've asked FitBit customer service and oddly they didn't know and said they would check into it. It's been two days and I have the sneaking suspicion they will never get back to me. This sadly has been my experience whenever a really tough question is asked.
I think people want to know, because it is useful to have both services at the same time and that doesn't eliminate the need for the FitBit. It actually should mean you get a more accurate step count over the day.
Community Moderator Alumni are previous members of the Moderation Team, which ensures conversations are friendly, factual, and on-topic. Moderators are here to answer questions, escalate bugs, and make sure your voice is heard by the larger Fitbit team. Learn more
Best Answer
