tcjohnsson
Well-known member
Just curiously, I am a numbers geek, too, so I get the "second by second" basis "want to know" thing, but the truth is - Heart rate monitoring really goes by an average. Can you tell me why it matters that your heart rate is EXACT every single second? It really doesn't, if we think about it. It's nice, for those of us used to a Polar, to see EXACT numbers..but at the end, it matters what you maintained during the workout, not what it was at 37 minutes and 12 seconds in to it. Maybe we need to rethink how important the exact accuracy is and stop being so OCD. Myself included.
You're right... it doesn't matter if it's correct every second. But that is not the case whatsoever. The Gear 2 will go more than just a second or two being inaccurate - try 5, 10, 20 minutes or more straight. This completely invalidates peoples' exercise sessions (caloric expenditure feedback) when they may be pushing "hard" for only 10-20 minutes out of their entire daily workout. I'm going to illustrate the gross inaccuracies of the Gear 2's HRM for you with the following images. I am wearing both the Mio Alpha and the Gear 2 very tightly against my wrist (see my skin creasing up along side of the watches on the first image) and wearing them so the sensors are facing the more sensitive underside of my wrist as some suggested I do. There were no wild movements - all exercise is done in a controlled environment and my hands/wrists were being very still holding the treadmill's safety bars and HRM sensors. Note that the Mio Alpha was compared to the Zephyr and Polar chest HRMs and they would always be within 2-3 bpm of each other. Consistently. The Mio is extremely reliable. I also tried swapping the two on another test so that Mio was closer to my hand and the Gear 2 was further from my hand. Both tests yielded the same gross inaccuracies.
The first image shows me driving to the gym (taken immediately after a quick walk to my car). Note I'm reading 72 bpm on my Mio Alpha which is consistent with my Polar and Zephyr chest strap HRM but we have a whopping 138 bpm on the Gear 2. Note that I am sitting in my car driving (slightly elevated at 72 bpm because I just briskly walked to my car) - not running at a relatively fast pace as a 138 bpm rate would suggest. Note the elapsed time as I started the exercise app (hiking) earlier in the day.
The second image shows me on a treadmill walking at a very fast pace on a 14% incline. The Mio has me at 121 while the Gear 2 thinks I'm just sitting around at 73 bpm! You can see the treadmill rubber band track below the watches. Note the elapsed time at 2:17:48.
Here on the third image I am running on the treadmill at a quick pace on a 14% incline (just stopped quickly to take the pic). You can see the perspiration forming on my arm. Note the elapsed time of 2:22:47. The Mio has me at a fair 139 bpm (the treadmill HRM showed me at 138 bpm; sorry tried to include in pic to throw it into the comparison but once I took my hands off the sensors it disappeared). The Gear 2? Yup, nailed it. WAAAAAY OFF at 84 bpm.
Do you see how grossly inaccurate this device is? I hope this shows some of you that the device is not just utterly useless - it's an insult to those that bother using this feature at all.
Finally, I wanted to add that the caloric expenditure calculation on the Gear 2 is also horribly inaccurate (actually more inaccurate than the HRM believe it or not) - this is completely exclusive of the broken HRM. Despite the huge discrepancies evident in my images above, the Gear 2 did report the data while I was on a stairmaster for about 30 minutes and it was within 25-30 bpm accuracy for most of the duration. Check out the last image where it shows my total caloric expenditure over the 50-minute period at the gym which included mostly medium to high energy output. What did I burn? 76 CALORIES!! I burn that much just walking around the mall for 30 minutes. The gym Stairmaster's computer depicted a caloric burn of 270 calories alone (I ascended 146 stories). The Gear 2 was monitoring my heart rate the ENTIRE time. So not only is the HRM useless, the algorithms used to extrapolate the HRM data is grossly inaccurate too. Everything about this device from a health-tracking perspective is a major failure.
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