The Polar OH1 allows you to exercise without carrying a Bluetooth device and stores that data for later. This is perfect if you want to know your heart rate at the gym and then keep track of your training long-term on your phone or computer.
When exercising intensely, you may not want your thousand-dollar phone in your pocket as you flip tires or climb walls. If this is you, the Polar OH1 is the best heart rate monitor.
Unlike other monitors here, the OH1 has internal memory, meaning you don't need a watch, phone, or bike computer to store your heart rate data. In events like obstacle racing, it's useful to have a record of your exertion — especially if you track your training carefully — but any phone or watch is not going to survive the first 10 minutes of a muddy assault course.
The OH1 is the perfect solution: It's lightweight, arm mounted, and perfectly capable of connecting to a phone or other device if you want to use it like any of the other straps here. At $79.99 it isn't much of an upcharge for having the ability to store 200 hours of workout data on this tiny strap.
Like the Wahoo, the Polar sensor uses optical monitoring to measure heart rate on your arm. It uses a soft strap that, I found, best stayed in place when secured snugly on my upper arm. As with most of the optical systems I tested, I did have to use a bit of trial and error to find a place where the sensor stayed put and recorded accurately.
The bundled app is required to start the sensor for the first time and features a lot of interesting data-analysis tools, such as quantifying training load and calorie burn. The sensor itself is small and unobtrusive — far less bothersome than some other data storing monitors I tested. It's easy to set up the OH1 to either record and transmit or just transmit. Amazon buyers loved the accuracy and ease of use of the OH1.
All this data storage and connectivity do come at a cost: The OH1 delivers only 12 hours of use per battery charge. Most of us aren't exercising for that long, but it means that if you travel or simply tend to forget to charge your strap, you might find yourself missing the data you want. As DC Rainmaker noted, the Polar charger, which plugs directly into a USB power adapter, can be a bit fiddly to use; it is very compact, so you can travel with it.
The OH1 also doesn't support ANT+, which won't be an issue for most but if you use a bike computer and want to pick up heart rate, you should check that the computer has Bluetooth compatibility.
Is the OH1 for you? If you do obstacle course racing or prefer to keep your workout and your phone apart, then absolutely. But if you can't think of why you'd want your strap to store data when you just want to see your heart rate on your phone or bike computer, then you'd be better served with a strap with longer battery life.
Pros: Unobtrusive and accurate, stores up to 200 hours of data
Cons: Battery life, charger a bit awkward to use
Buy the polar OH-1 on Amazon for $79.93