John Galea's Blog

My blog on Gadgets and the like

Scosche Rhythm+ heart rate monitor

A heart rate monitor makes calorie counts from applications tracking fitness on your smartphone a whole lot more accurate. For years the best heart rate monitors have been chest straps. They work well but are uncomfortable. Especially when doing aerobic sports like mountain biking for example. Wrist based heart rate monitors have always been a grail, but they are inaccurate. I recently reviewed the Mio Link and ended up returning it due to inaccuracies.

Another blogger DC RainMaker brought this one to my attention. I previously played with Scosche’s earlier model but returned it due to poor application support. DC Rainmaker did a thorough post so I won’t repeat his excellent work, just add my own spin.

The previous generation of Rhythm had some issues. The clip to charge it was so tight it felt like you were going to break it. This one is much better. The previous one came in a ghastly yellow color. This one is an innocuous black/grey. The neoprene strap had no holes so it didn’t breath which meant you sweated under it. This strap is thinner, made of better material and has holes so it breathes. The previous model was Bluetooth only. This one is Bluetooth low energy and Ant+ giving it great compatibility going forward as well as compatibility with older Garmin devices. So it looks like Scosche learned from their previous model.

So this HRM (heart rate monitor) is optical in nature. It comes with a two sizes of straps, and a USB charger. I’ll steal DC Rainmakers pic 🙂

A tip, I found the hrm took a bit of time to zero in on an accurate reading. Think 1-2 mins. I also found it best to turn it off and back on if you move where on your arm you are going to put it.

It is meant to be worn on forearm. But I thought I would try it in a few other places.

The smaller strap is small enough to wear it on the wrist. So I thought I would try it. Sure enough, like the Mio it’s not accurate on the wrist. I tried it on the outside of the wrist (like a watch) and no the inside both were inaccurate. (Scosche do not suggest this would work, I just tried it to see.)
Graph of the data on the outside of the wrist.
Graph of the data on the inside of the wrist.

I also tried it on the bicep on the outside. This also tracked poorly. (Again, Scosche do not suggest this would work, I just tried it to see.)
Graph of the data on the outside of the Bicep

On the inside of the bicep it worked quite well, and I find this more comfortable:
Like the Mio I did have some issues in busy places with the Bluetooth Low energy dropping out. Fortunately the app I was using BLE Heart rate monitor has added auto reconnect.

So with all this I then went out for a mountain bike ride and did three runs. The first one is with the Scosche on the inside of the bicep. As you can see it tracks pretty well. I’m not sure if that first little blip is because I didn’t wait long enough for it to settle or what but as you can see in the graph it tracked pretty well. This is where I find the Scosche the most comfortable.

These last two are with the Scosche worn on my right forearm. Which by the way, is where Scosche recommends it be worn. I find it starts to irritate me in that location after a while. No idea why. Especially so on the left forearm. As you can see in these graphs when worn as recommended this hrm is VERY accurate when compared with a chest strap hrm. By the way I also did correlation runs between my Garmin and Zephyr chest hrm to see if they are accurate.

Battery life is impressive. After 8 hours it was still at 51%, but it drops off oddly after 51%. I got just under 9 hours of battery life. But don’t count on the battery% indicator. The curve shows how it drops off.

So all in all the Scosche is an excellent HRM and is so much more comfortable than a chest strap hrm. The ANT+ compatibility means I can use it with my Garmin Foretrex 401 and an app on my phone at the same time. And with Bluetooth low energy I can use two apps (for example Endomondo and RunGPS) on the phone at the same time (one connected with Ant+ and one with Bluetooth low energy). I wish the Mio had been accurate it was super comfortable. Oh well …

Update: I was using this monitor in -2C the other day and noticed it seemed to be inaccurate. So I sent an email to Scosche and they informed me the temperature range of the device is 5 to 40C.

August 20, 2014 - Posted by | Android

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