Quantifiedself.com recently had a few posts comparing the Nike FuelBand with the Fitbit Ultra. Since I’ve been using both devices since August, I thought I’d pull my data and weigh in. From my experience, the Fitbit consistently reports higher numbers than the FuelBand and the discrepancy seems to increase as my activity level increases. These results are very similar to Bastian’s, but it was interesting to see that Ernesto found the two devices to record nearly identical step counts during his one week test. My current hypothesis is that since FuelBands are worn on the wrist, they have to eliminate hand movements from their step counts, and the FuelBand might be not counting a lot of valid steps because the algorithms are miscategorizing the movement.
Below is a graph of my steps since August 14, 2012 when I bought a FuelBand (I already had a Fitbit Ultra). This should be roughly 160 days worth of data, but I’ve removed about 40 data points because I have repeatedly lost, forgotten, or washed my Fitbit and didn’t have comparable data on those days (for what it’s worth, Fitbit’s customer support has been great at providing me with replacement devices). As you can see, the blue line (Fitbit) tends to be higher than the red (FuelBand), and the differences are highest on my high activity day where the blue spikes, but the red doesn’t.
Here’s another chart showing just the difference between the two devices. Positive numbers are where the Fitbit had a higher step count, negative are where the FuelBand did. As you can see, almost all of the numbers are positive. In fact, the results weren’t even close. My Fitbit had a higher step count 81.5% of the time.
On January 12, I replaced my Fitbit Ultra with a Fitbit One. I’ve only had it for ten days, but I feel like the One counts fewer steps than the Ultra. The differences are small and unfortunately I can’t directly compare the two devices since I gave away my Ultra, but the delta between my Fitbit and FuelBand step counts has narrowed slightly (down from an average difference of 18.2% to 17.0%). It’s too early though to tell if that difference is significant.
A few other notes, I used to wear my Fitbit clipped to my pocket, but after repeatedly losing it, I now leave it in my pocket clipped to my keys which I always have with me. It’s possible that my jingling keys might increase my step counts, but that seems unlikely. As for my FuelBand, I wear it on my left wrist and I am left-handed. If this is increasing my step count, it’s not doing it enough to make the FuelBand steps catch up with the Fitbit.
I’d like to run some more calculations and use a bit more advanced statistics to compare the two devices, but I think I’ll wait until I have at least a month or two of data from my Fitbit One to see if there are any differences between the two devices.
If anyone wants to play with my full data set, the Excel file is here: Fitbit vs FuelBand