I’ve been thinking about writing something in medium.com about that. Right now, I’ve got 4 fitness watches on me, a “study watch” from Google’s Project Baseline on the right arm, and an IWatch, Fitbit Charge 4 and a Garmin 4 on my left. Let me explain.
I bought a Fitbit One back in late 2012 when they were still having problems getting their shipping department up and running. About 4 years ago I got into the Baseline study and they put a watch on me. All it does is let you watch your ecg being measured, and gives you your steps the next day in the app. That’s because they are basically calibrating it through wide use. But, I was bothered because I wanted more data, so I bought a Fitbit Charge 4 and have been wearing it all along. First one died, so I bought another.
Then, my kids figured they ought to get their dad an IWatch to monitor his heart (borderline antique), and then I got into a Stanford study which gave me a Garmin. I’m told the IWatch, Fitbit and Garmin all have GPS; in fact, the Stanford study is tracking that, among other data.
I have not investigated the ability to harvest the Apple watch data; Fitbit lets you download some and, as I recall, will sell you CDs with historical data. Since Stanford is tracking my Garmin, it seems clear there’s a way to do that, but have not checked.
I can say this:
Fitbit and Garmin agree pretty well on steps, don’t seem to agree at all on “floors” (maybe they each define them differently), and are not all that comparable on sleep cycling; the IWatch needs you to download another app if you want to see your sleep stages.
I must charge the iWatch daily, Garmin every couple of days, and the Fitbit goes close to a week.
I noticed that Garmin is smart enough to stop measuring oxygen when the battery is low; Fitbit seems only to do so while you are sleeping.
One more point: I’ve taken to calling my IWatch “Bitchy betty” (after the famed FA-18 pilot’s associate known as “bitchin betty”) because, while the fitbit does a tiny bit of buzzing, and, when you cross a 10k steps threshold, it goes off on bitgasms, buzzing like mad, the IWatch does beeps, chirps, and it thunks on your arm. It does that enough to drive you to distraction. I suppose there’s a control for that, but the documentation reminds me of the prime reason you have kids - to have someone to program your damned VCR. Old farts don’t take well to diving around in menus which appear to be designed by people who don’t know an ontology from a tailpipe. Which is why I’ll conclude with this: Apple’s UX sucks (appearance is gorgeous, usability, not so much), Fitbit was nice for years, but Garmin really gets UX.