A tale of fail with the Fitbit Sense (way overcounting)
I’ve mentioned on Twitter that I’m currently wearing two fitness watches. Yeah, styling and profiling I know. Both are within 1% of each other when I’m actually exercising/walking. I mean it is shocking how close they are considering I am not a robot walker.
I’ve also mentioned that I don’t seem to be getting my expected results in my exercise and diet from the information I’m getting back from the Sense.
TL;DR – Fitbit Sense is counting thousands of fake steps when not exercising.
I had chalked this up to metabolism, being old, etc, but after getting on some machines at the gym my results started lining back up with what my expectations were from 10ish years ago.
I asked Fitbit support a couple of days ago if it mattered whether I was wearing the watch on my inner or outer wrist, they said yes, I changed the orientation, verified my stride length which had been set by the GPS, verified the arm side was set correctly. All seemed good. Results on the watch did not change.
I’m under embargo on one of the watches, but after comparing it to the @fitbit Sense and then consciously counting my steps all yesterday (yes, I was that bored,) I found that the Fitbit Sense was counting thousands of steps I did not take during times I was not doing jack.
Yesterday was what I would call a sloth day. I did nothing. I woke up, got the kids ready, this was one of two days a week Kim took them in. I went back to bed as I didn’t have anything at work, and 3:30pm somehow rolls around with me having slept an additional 7.5 hours and having walked down and up 13 steps, to the kitchen, made kids some food, got them to the car, and at this point the Sense was saying I had about 1500 steps, and the medical grade was at 350.
I’m going to point out this is not a regular occurrence. I was just really really really tired and can give you the whole rundown of what made me so tired, but it doesn’t matter.
I was attempting to keep a running count of my sloth day, it was somewhere around 700 steps based on what I could measure out and by what I had counted. The Fitbit Sense tells me I did 1886 steps, the medical grade told me I did about 600. Now, what’s so infuriating about this is I am not seeing where and when these false steps are happening. Like I’m sitting here typing and the count may go up by one or two, but it’s not going up at any rate that would account for the roughly 1,186 additional steps. Checks fitbit logs – ok, I am now seeing where and when.
1000 or so steps doesn’t sound like much in the course of things, but with 700 being the base, it’s right at 270% overestimating. I’ll point out here it’s stacking these in when I’m not looking, not when I am looking. I’ve had days when I reached 10,000 steps on the Fitbit and I just know that’s wrong.
Using the Fitbit dietary calculator it takes your goal (mine is slow weight loss, if I overly under-calorie my metabolism shuts down,) and factors in how many calories you’ve burned – from this you get a suggestion on how many calories you can eat and still lose weight. In my case I’m being credited for 270% of the exercise. This screws that up.
Once again, this is when I’m not moving that I’m getting this credit. When I am moving the thing is dead on and in line with the medical grade. Like I’ve typed all of this and I’ve added a total of 10 steps if that. I don’t find this all that offputting, my arms are moving, I get we’re going to have some false strides accounted for, but 10… that’s about one a minute while typing.
What I do notice however is when I am walking and paying attention, the count is dead on.

A look at the step count by minute above says that I did 238 steps from 7:15-7:20. Check cameras, nope. During that block I walked from my kitchen to the living room, got the kids to a car. Maybe 100 steps.
914 steps are recorded for that little timeframe of me walking downstairs, getting kids up, going into the kitchen and making some sammiches, walking to the living room, and taking walking them to the car and then going back to bed. As noted, sloth day.
I mean, I am a tenth of the way to my goal of 10,000 steps a day from going to the kitchen and making PB&Js for the kid’s lunches. Whooo hoo..
Step count based on other days is about 300 for me to get the kids up and ready.
I kick it into GPS walk mode, it’s dead on. I look at it and walk. Dead on. I make a PB&J bam I’m in marathon shape. I pay attention to the step count on the watch – dead on.
I’ve only been counting for a couple of days at this point, but based on medical grade watch vs the Sense we’re looking at an overcount of generally 60% which I had initially attributed to the medical grade undercounting.
Next test is to swap wrists with both of the watches and see if anything changes.