Why You Can Trust CNET Garmin Forerunner 235 review: The best watch for casual and serious runners
The Forerunner 235 tracks pace and distance, provides easy-to-read smartphone alerts and has a ton of running features that are typically found on more expensive watches.
The Garmin Forerunner 225 was one of my favorite running watches of 2015. It was a device I personally recommend to numerous friends and family members, but there's a new king of the hill -- the Forerunner 235.
Garmin Forerunner 235
The Good
The Bad
The Bottom Line
The Forerunner 235 does everything both casual and serious runners would want. It has GPS to measure pace and distance when running, it has an optical heart-rate sensor, and it can track daily activities like steps and calories. These are all features shared with the Forerunner 225, but the 235 can do even more.
It can display notifications from your iPhone or Android device and has access to Connect IQ, Garmin's third-party app store. It's also sleeker, more comfortable to wear, and like most of Garmin's products, it can be worn in the shower and while swimming.
But one of the most appealing things about the Forerunner 235 is the price tag. The watch is available for $330, AU$469 or £270, only $30 more than what the Forerunner 225 was offered for. All in all, you now get way more value with little to no sacrifices.
It's easily one of my new favorite watches for both casual and serious runners, but there's a few things you need to know before you go out and buy one.
Changes from the Forerunner 225
The Forerunner 235 adds more than a dozen new features to the 225. It's also thinner, lighter, has a higher resolution display and less of a bezel. The watch adds all-day heart rate tracking, smartphone notifications, music controls and access to Garmin's Connect IQ app store.
The Garmin Forerunner 235 (right) is slimmer and lighter than the Forerunner 225 (left).
On the fitness side of things, it includes support for GLONASS (the Russian GPS satellite alternative), which helps improve locating you in areas where GPS may be limited. There's also a feature for predicting your race times and a recovery advisor to help you determine when you're ready for that next hard workout.
The watch can even estimate your VO2 Max (a metric used by athletes for measuring the maximum amount of oxygen that can be used during workouts). All of this is in addition to the basic running features like auto pause, auto lap, interval workouts and keeping track of your personal records.
Running with the Forerunner 235 is enjoyable. It's comfortable to wear, the satellite signal is acquired almost instantly (even in New York), and it's pretty accurate. The recovery advisor seemed a bit off, as did my VO2 Max estimates, but they are just that -- estimates.
As for you cyclists out there, while the watch is primarily for running, you do have the ability to pair ANT+ speed and cadence sensors. Unfortunately, there is no support for any Bluetooth sensors.
The heart-rate sensor isn't perfect
Garmin decided to use its own in-house technology, called Elevate, for the heart-rate sensor on the Forerunner 235. The method is similar to other sensors: Three green LED lights are used to light up the capillaries while the sensor measures how fast your blood flows past.
Unlike with the Forerunner 225, the sensor on the 235 will run continuously throughout the day. Like its predecessor, I found the heart rate data to be relatively accurate. Resting heart rate fluctuated between 47 and 50 beats per minute (bpm), which is normal for me. Easy runs produced results similar to those recorded on a Polar H7 chest strap, although the 235 was delayed by between 3 and 6 seconds, but that's fairly common for optical sensors.
It was when I did an interval workout that I began to notice some flaws. Both devices recorded my heart rate each second. I then exported the data and analyzed it in an Excel spreadsheet. You can view it below.
As you can see, during my 12-minute warm up the heart rate information is similar between the two devices. The data remained consistent during my first interval and through my first rest cycle. Starting with the second interval, however, the Forerunner 235 struggled to keep pace with the chest strap. At the 21:30 mark, it measured my heart rate at 164, while the chest strap had me at 184.
This continued for subsequent intervals and rest cycles. It wasn't until a few minutes into my cooldown that the Forerunner 235 was able to close the gap. At the 50-minute mark, the watch measured my heart rate at 159 bpm compared to the chest strap's 166 bpm.
The problems I encountered could possibly be ironed out in a future software update. If you need up-to-the-second accurate heart rate data, there is the option to pair an ANT+ chest strap to the Forerunner 235. It should also be noted that the further the watch is from the wrist bone (about two finger lengths) the more accurate measurements will be.
The heart rate data recorded on the Forerunner 235 can also be shared to other ANT+ compatible devices, such as Garmin's Edge bike computers. It's a bit tricky to set up, though. You have to scroll down to the heart rate watch screen, then press and hold the up key, and select Broadcast Heart Rate.
Garmin's app still needs work
Garmin has been slowly improving its Connect mobile app on Android and iPhone. There's now personalized insights and feedback based on your daily activities. The app is better than it once was, but it's still not as good as what Fitbit and Jawbone offer.
Garmin simply tries to do too much with it. These devices can record a ton of data, but there are simply too many menus to browse through to find all of it. I've used Garmin devices more than anyone I know, and it even took me a couple of minutes to figure out how to disable or change certain features.
I've also experienced occasional hiccups with connectivity between the app and the watch. Sometimes the watch wouldn't sync my workouts until I opened the app, which was a little annoying. Other times the watch would disconnect from the app for a few minutes before reconnecting. It didn't happen very often, but app connectivity is still something Garmin needs to work on with all of its products.
The Forerunner 235 also supports third-party apps, watch faces and widgets...sort of. The Connect IQ store, which can be accessed from the Connect app, has been around for a year now, but it still lacks useful apps and widgets. There's potential here, but it doesn't seem like developers have jumped on board just yet.
Battery life is good
The Forerunner 235 will last you about 11 hours with an active GPS signal, an hour longer than the 225. That time drops to under 9 hours if you use both GPS and GLONASS. Garmin has said that in watch mode with notifications and heart rate enabled, the watch should last up to nine days. I generally charged it once a week, but your time will vary based on how much you run.
The best overall GPS running watch
If you're looking for a GPS running watch with heart rate, the Forerunner 235 is worth the investment. The heart rate measurements aren't perfect during hard workouts, but the benefits of the watch outweigh the cons by a mile. It's accurate at measuring pace and distance, provides easy-to-read smartphone alerts and has a ton of running features that are typically found on more advanced devices. Simply put: It's a great value.
If you aren't interested in heart rate, the Forerunner 230 is equally appealing. It has all the same features as the 235, but is $80 cheaper and doesn't have an optical heart-rate sensor. While the watch gets better battery life (16 hours with GPS, up to five weeks as a watch with notifications), certain features, such as the recovery advisor and VO2 Max estimates, will require a heart-rate chest strap to use.