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Are heart rate monitors on fitness trackers accurate?Several fitness trackers, as well as the Samsung Galaxy S5, now boast the ability to measure your heart rate. How do their readings stack up to an EKG? CNET's Sharon Profis, with help from Kaiser Permanente cardiologist Dr. Jon Zaroff, puts the Garmin...
[MUSIC] The EKG, which is what we're recording with electrodes, shows the electrical activity in the heart, so that's an electrical sensing technology. So these chest straps, essentially have an EKG lead right over the chest, so it's the same technology, so we would generally expect that to work very well. Whereas an optical sensor is not near your heart and it's not. Sensing the electrical activity with your, in your, within your heart. It's sensing the flow of blood to your capillaries, one pulse per each heartbeat. In the beginning when these wristbands came out, they were essentially glorified pedometers. Now we're seeing them incorporate heart rate monitoring. I should be able to get a continuous heart rate from this guy. Good. So far, resting this seems to be pretty accurate. But we should see how it does when I get my heart rate up. How is your device looking? So right now, my chest strap is sending signals to the Vivo Fit, and it's reading 175. Wow. That's spot on. That's pretty dead on. For this one, it comes in a clip and an arm band. So, you would have it on your waist, and you would take out the pulse. Okay, so there's the heart. Now I have to place my finger over this optical sensor here. So, the pulse, 02, is telling me I'm at, 93 beats per minute. Our EKG [LAUGH] is about 50 points above that at 146. So we know that's, not only not accurate, it's way off. Our next contender, is the Basis Carbon Steel. And this one, like a lot of the wearable heart rate monitors, is a on-demand heart rate monitor. So, you'll have to queue it up, to let you know what your heart rate is. I'm trying to get the heart rate right now, but it's not working. And I wonder if it just can't tolerate any movement whatsoever. Okay, we should stop and see if it's maybe because I'm moving around too much? So I'm still trying to get my heart rate. It's all the way up to 170 and it's still not getting it. Yep, it's about 130 by the old fashioned pulse rate too, and you do have a perfectly strong wrist pulse, so. Okay. So? Not sure what the problem is. Doc says 130. Carbon Steel says 86. That's a no go for us. Here we've got the Samsung Gear Fit, and this one has an optical sensor. So when I enable the heart rate monitor, a light will illuminate my capillaries, and then a sensor will see how often the. Blood is pumping. Is that right, doc? Okay. So, here we go. I'm gonna put it on first. Get my resting heart rate. Okay, I've got 110. The EKG says, well at the time, it said 117. Right now we're going to simulate what it would be like to exercise. And then pause to get your heart rate, because this one won't let you measure while you're in action. Let's see how it performs when my heart rate is really up. So it's still unable to measure. A couple of minutes have passed since I stopped exercising when my heart rate was up at 180. Now it's down to 128. So we'll see if that helps the fit measure my heart rate. The gear fit says 104, it finally got my reading. But the EKG says 141, so that's way too far off. Our last contender is the Galaxy S5. And this one has a built in heart rate monitor right here on the back, it's an optical sensor. It's kind of a wild card. Lots of people think it's a gimmick, but now we can actually put it to the test and see if maybe it's accurate. I launched the app, I'll hit start and the light illuminates my finger. So it's measuring right now. It's asking me to keep still and be quiet so I won't talk anymore. 150. EKG says 147. That's, that's not bad at all. Do this right away. Alright, I have my app out. Start, my finger. You see the red light there? Alright, we're at 190 over there. 193. Excellent. So far that's the fastest and the most accurate. And it's on the phone. Now that's [LAUGH] really inconvenient if you're exercising. The last thing you wanna do is carry around. A phone this large, that's really the point of these wearable devices but, if you want a pretty accurate reading, that's pretty dead on.