Casio has unveiled its latest Pro Trek Smart smartwatch and the big news is that it's bringing a heart rate monitor to one of its Wear OS watches for the very first time.

While heart rate monitors have now cropped up on most smartwatches, the omission from Casio's outdoor smartwatch range has always felt like a peculiar decision to us.

Wareable verdict: Casio Pro Trek Smart WSD-F21HR review

Casio Pro Trek Smart WSD-F21HR key specs Available in red and black

Compatible with color maps

Built-in GPS

GLONASS/MICHIBIKI support

1.32-inch, 320 x 300 dual layer display

Waterproof up to 50 metres

Same sensors as Pro Trek Smart WSD-F30

Optical heart monitor The Pro Trek Smart WSD-F21HR changes that with the addition of an optical-based monitor letting users view heart rate zones in real-time. There's also a new Heart Rate watch face that switches to the heart rate monitor screen when movement is detected via the accelerometer motion sensor.

Aside from that heart rate monitor, it seems we can expect much of the same in terms of what we got with the last Pro Trek. The WSD-F21HR is built to military standards in terms of durability and is waterproof up to 50 metres. It still includes that same dual-layer display and you still get built-in GPS and the ability to download offline maps.





It does of course run on Google's Wear OS, giving you the full gamut of Wear features including notifications, Google Assistant support, customisable watch faces and the ability to download apps.

Speaking of apps, Casio is introducing an enhanced version of its Activity App, which now offers profiles for running and trail running. You can customise the data shown in these running profiles to include heart rate data as well.

Read this: Best outdoor GPS watches



Battery life on previous Casio Pro Trek smartwatches haven't been all that great, and it doesn't look like that's going to change with the new one. Casio says you can expect 20 hours of battery using the GPS and heart rate. In normal mode (not using GPS), it's 1.5 days and approximately a month if you're basically just using it for the time.

Price-wise, you'll need to part with $499 for the WSD-F21HR. That's basically the same price as the Casio Pro Trek Smart WSD-F30. So you're not paying a premium it seems for the addition of heart rate. It's launching in September, so hopefully we won't have to wait too long to see what Casio's new outdoor smartwatch is made of.