As a runner and a running coach, not surprisingly, I have an interest in the runner’s heart and measuring its activity.
But, I gave up on heart rate monitors some years ago. It’s not that I’m not interested, I just couldn’t get any meaningful results from any devices I tried: Polar (x 2), Cardiosport, Garmin, they all gave very unreliable data; all were chest-strap devices. Sometimes I got half-decent readings by using lashings of electrode gel and a very tight strap, but that wasn’t ideal or even a particularly durable set-up.
However, recently I obtained a Tomtom Runner with optical heart rate (OHR) monitoring. No chest strap, the monitor works by shining high-intensity light on to the skin and analysing the result. High-pressure blood causes less light to return to the sensor, thus the pulse can be detected — very clever.
But, I wasn’t quite there yet. The TomTom Runner watch has an integral lighting unit on the back of the watch. This sounds great, but in practice, it’s hard to maintain the constant contact required for accurate measurement. I also found that the unit took a long time, perhaps ten minutes or more, to even begin to record accurately. Furthermore, once it was stabilised, the monitoring wasn’t particularly consistent. I already knew that I have an odd-shaped chest, and now maybe my wrist isn’t quite normal either. I achieved better results by moving the watch towards the elbow. But, not surprisingly, it was difficult to keep it in that position; the watch wanting to move to the thinner part of the wrist. Although it wasn’t ideal, I was quite encouraged and could see that optical heart rate monitoring can work.
I began checking out other wrist-based OHR devices which seemed to be used with varying degrees of success by other users. My research led me to an alternative that monitors heart rate optically but is not part of a watch.
Polar OH1 +
Because it’s not part of a watch, the Polar OH1+ can be positioned in a more reliable position, either on the forearm or upper arm between the elbow and shoulder. Polar OH1 +. It is a very small device, not much bigger in diameter than a pound coin or American Quarter, 9.5mm thick and weighing just 5g.
The Polar OH1+ can operate in two modes
- As a HR sender unit
- As a standalone HR recorder
When used as a sender unit, the device sends real-time HR data to another utility, for example, a sports watch, cycle computer or training app such as Strava. It’s very simple to set this mode, just switch the device on with a press of the silver button on the side. Depending on your receiving device, you might have to pair the OH1 first. In my case with TomTom Runner, all I needed to do was turn on the HR sensing from the watch menu by pressing the down button, then selecting ‘SENSORS’, then ‘HEART’, then ‘ON’. That’s all that was required, from then on, if the Polar OH1 is switched on the heart rate reading is displayed on the watch. This was surprising to me because HR monitoring on the TomTom Runner is not obviously facilitated.
But you don’t need a watch or even a smartphone to record HR data. As a standalone recorder, the Polar OH1 + can store up to 200 hours of training data, which later can be later uploaded to the Polar Flow app for analysis. However, be sure to actually switch on in standalone mode otherwise nothing gets recorded. This caught me out a couple of times before I realised what was happening. One press switches the OH1 on, but then you must press the switch twice to turn on the standalone mode. This is a little trickier than it seems because the press-button switch does not have a tactile confirmation that it’s been switched; there’s no click to it, so it’s hard to tell if the two presses have been registered. The way to tell for sure is by looking at the LED on the opposite side to the switch.
These two modes can be run together
The original OH1 communicated to other devices by Bluetooth only, the newer ‘+’ (or plus) version also incorporates ANT+ technology. ANT+ is used for many wireless sensors, mainly in fitness monitoring applications, e.g heart-rate monitors, speed and cadence sensors on cycles, GPS trackers, etc. I had no trouble at all using the OH1 + with my TomTom Runner watch. As far as I know, my TomTom is the first version and whilst it’s not obviously a heart rate monitor, it was very quick and easy to set it up to show the readings from the OH1.
I also cycle and use a Bryton 10 cycle computer (which by the way must be one of the most value-for-money cycle computers out there). Again, very easy to set up the OH1 + directly from the Bryton 10.
The TomTom Runner uses Bluetooth and the Bryton 10 uses ANT+ for their respective pairing connections.
Charging the OH1 +
The box contains a USB shoe to hold the OH1 and connect it to a USB port on computer or charger socket. This is unique to the OH1 and it is small, so it’s worth taking care of it. It’s clear how to insert the OH1 into the charging cradle because there are electrical contact points that need to be matched.
The LED shows green when fully charged. a full charge should last for 12 hours of training time.
LED Guide (from Polar instruction manual)
Charging: Yellow LED blinks slowly
Battery full: Green LED continuously on
After Switching ON
Battery status normal: Green LED blinks five times
Battery status low: Red LED blinks five times
Using as a SENSOR
Heart rate not detected: White LED blinks once every two seconds
Heart rate detected: Green LED blinks once every two seconds
Using as an independent training device
Training recording set on but first time use not done: Red LED blinks three times
Heart rate not detected: White LED blinks quickly twice
Heart rate detected: Green LED blinks quickly twice
Battery low: Green and Red LED alternate every other second
Battery critical: Red LED blinks quickly
During Fitness Test
Heart rate not detected: White LED blinks once every two seconds
Heart rate detected: Purple LED blinks once every two seconds
Connecting, Syncing or Pairing: Blue LED blinks
Searching or waiting for confirmation: Blue LED blinks quickly
Updating firmware: Blue LED continuously on
Error: Red LED continuously on
Using the Polar OH1 +
There are various mounting options for the device. For swimming, there is a goggle mount which positions the sensor at the temple. For running/cycling, etc there is an armband. I’ve not used the google mount.
It’s easy to mount the OH1 into its armband. The armband holds a plastic shoe for the device; it’s just a simple push-fit.
It does not need to be tight, just tight enough to stop it moving is fine. When mounted in its armband, I found the OH1 to be very comfortable and hardly noticeable (unlike a chest strap).
Streaming heart rate to a watch or an app
To start streaming heart rate data just switch the unit on with one press of the silver button. The six green monitor LEDs light up brightly. Then you are good to go and you should see heart rate displayed on your watch or app (if you don’t then check the pairing instructions of the receiving device). As mentioned, with my Tom Tom Runner I just needed to ensure that the watch was set to read an external HR sensor.
Using as a standalone heart-rate recorder
As already mentioned, if you want the device to record HR data (and not just stream it to another device or app), then you must press the button twice whilst it is switched on. So the standalone sequence is:
- Press once to turn on
- Then press twice to activate recording mode
You can check that the monitor is recording by looking at the LED on the side of the device: the LED blinks twice quickly every 3 seconds. If it is just monitoring it blinks once every 3 seconds. When the device detects heart rate, the LED blinks green and when not it blinks white. So ensure the LED is giving 2 quick blinks before starting your workout if you want the OH1 + to record your session. If not set in record mode (but still switched on) it will pair and transmit HR data to your chosen app or device.
To turn off
Regardless of mode, one long press will turn the OH1 off. The six green LEDs will switch off to confirm.
Where to buy
The usual retailers of fitness gadgets: running, cycling, triathlon retailers, I got a good deal on the Polar OH1+at Amazon
I highly recommend it; at last, I can see reliable heart rate reading both in real-time during the session and also for analysis on Strava or Polar’s own Polar Flow app.