Kirk McElhearn puts a Fitbit One and his Apple Watch through their paces, to get a sense of the accuracy of the Apple Watch as a fitness tracker.
Lots to read here, but from his conclusion:
I’ve said before that fitness trackers are more about motivation than accuracy. If they get you to be more active, by prodding you to reach new goals, then they are successful. They should give you reliable data about your activity, though, and not be far off the mark. (I consider that the 5% difference in step count is acceptable.) But they shouldn’t lead you to wonder whether your activity is counted correctly, as the Apple Watch does. Either the Apple Watch is severely flawed in its fitness tracking capabilities, or I received a dud (I’m going to call Apple later to try and find out). I’m curious as to whether other readers have compared the Apple Watch with other fitness trackers, or whether anyone has similar data, reported by the Apple Watch, which just seems wrong.
I think accuracy is incredibly important if you use your Apple Watch to manage your personal health. The difference between a long run at 150 BPM and 145 BPM is not a big deal, but a run at 160 BPM when you think you are at 140 BPM can be life threatening, more so the older you get.
Obviously, as Kirk points out, accuracy in step counting is less critical, but it is important. If one device can get it right, then Apple should be able to get it right.
Clearly, this is Apple’s first kick at the can here, their first shipping medical sensor and their first activity tracking device. I have no doubt that, just like Apple Maps, Apple’s medical and fitness efforts will continue to evolve, continue to get more accurate over time.
The problem looks like he was just comparing the Apple watch to the Fitbit assuming the Fitbit is almost always is correct!
I mowed my lawn this past weekend wearing both an Apple Watch and a FitBit Flex (Apple Watch on my left wrist, FitBit on my right wrist). It takes about 2 hours to mow. FitBit clocked about 11,000 steps, and Apple Watch measured about 2/3 fewer steps, at 3,300. Given my pace and length of time walking, I’m inclined to say the FitBit did a much better job measuring steps. The interesting thing here is I think the step counting on my iPhone 6 Plus is more harmonious with my FitBit than the Apple Watch is, but I can’t figure out how to check the number of steps logged by my iPhone, which was in my pocket when I was mowing.
My wife is a personal trainer. She is very aware of her resting, zone 1-5 heart rate. She has indicated to me she see’s very accurate heart rate recording in the last few weeks with her Apple Watch. I also see very accurate heart rate with mine.
The Apple watch made me feel guilty on Sunday for not having exercised at all on Saturday so I dutifully went off and did a 5 mile cycle over 20 or so minutes. However for some reason the Activity App didn’t deem it of sufficient quality of access to add it to the daily figures. I can go and examine it but it seemed to think 20 minutes of cycling only burned 61 calories.
I’m confused.
But not deemed worthy to add to the exercise goal? Surely cycling for 20 mins is worth recording as exercise?
Apple Watch has been completely accurate for me.
the steps on your phone and watch are synced with each other. Also the watch must be used while walking/running with your phone to get a good baseline, which will then give you more accurate results when using by itself.
Maybe it didn’t get your heart rate up enough to count. That’s how it bases whether or not your activity counts as “exercise”.
It’s not clear that it’s the heart rate that counts as exercise. I’ve gotten several minutes for watering the lawn and for walking in a supermarket. And, if it is the heart rate, there should be a threshold setting; not everyone can do cardio.
Any Fitbit worn on the wrist is terribly inaccurate. I’ve tested two of them – the Flex and Charge – and they both overcoat by 20-30%, compared to the One, which is the most accurate, since you wear it on your belt.
The problem is that, if you mow your lawn likeI do, you’re not moving your arms back and forth much – you have them on the mower.
Also… 11000 steps is about 5 miles depending on stride length. Do you really walk five miles every time you mow your lawn??
It’s just odd that the FitBit recorded the number of steps so differently from the Apple Watch. Both devices are worn on my wrist, so I was expecting a similar reading.
Being that it takes me just under 2 hours to mow, I probably do get the 11,000 steps / 5 miles in. But who knows, the FitBit and Apple Watch are the only way I’ve ever measured it, and their readings are wildly different.
“but a run at 160 BPM when you think you are at 140 BPM can be life threatening” I don’t think this is true at all. Do you have anything to support this statement?
Accuracy of data is baseline important, but it’s only a first step. With so many of these devices, all we get is data, but no interpretation. That creates a situation where the only conclusion that can really be drawn is that more is better, something that would hopefully be obvious without a device. I’ve written about the hardware in the Apple Watch from a fitness perspective over at TidBITS, and I’m working on the software side of the equation next. http://tidbits.com/article/15663