Garmin Forerunner 735XT review

Garmin's GPS watch for triathlons ticks all the right boxes
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Garmin Forerunner 735XT
By Garmin
The 735XT is Garmin's most compact multi-sport watch yet, offering built-in heart rate and plenty of smart training metrics. At-a-glance notifications from WhatsApp, calendar and calls using a connected phone are also helpful, especially if out triathlon training for hours at a time. The battery goes the distance too while the optical heart rate tracking is surprisingly accurate, all sitting in a comfortable frame and strap combo. Throw in Connect IQ apps to add value and longevity and you've got an impressive long list of reasons to make this your next GPS watch purchase.

  • Strong battery life performance
  • Great Strava integration
  • Accurate heart rate data
  • Bland looking design
  • Some Bluetooth connectivity issues
  • Garmin Connect app needs refining

When it comes to Garmin watches, if you see an XT you know this device is built for serious training – these are the multi-sport specific devices. Since the release of the bulky Garmin Forerunner 920XT, the company has had its engineering wizards working on overtime to shrink the wrist-dweller to what's here in the Forerunner 735XT.

Despite being small enough to wear day-to-day, the 735XT crams in a powerful battery, optical heart-rate monitoring, all-day activity tracking, smartphone notifications and plenty of training metrics. But does it stand up to the competition from Polar, Suunto and TomTom?

Essential reading: The best outdoor watches to look out for

The price tag places this above some high-end running watches but below more comprehensive multi-sport wearables. Has Garmin found the sweet spot that makes this ideal for everyone? We got sweaty to find out.

Garmin Forerunner 735XT: Design and features

Garmin Forerunner 735XT review

When you consider how much this watch offers, the Forerunner 735XT packs everything into a relatively small body. It's light and thin enough to complete a full triathlon without worrying about noticing it – even when slipping off your wetsuit. But it also looks a bit basic.

We're all for minimalist designs and have to admit this does do everything you could need. There's a good enough sized colour screen and functional, easily controlled buttons that make for ideal access while bouncing about on a run.

The gripe? It could be better looking: less bezel, more metal and a punchier screen. The Polar V800, for example, has a great mix of metal and coloured buttons to add a bit more of a stylish feel. But if it's a toss-up between looks and functionality most sports watch makers, including Garmin, seem to go for the latter.

The strap on the Forerunner 735XT is excellent, with a slight stretch to the rubberised material. This makes for a snug yet comfy fit, which is ideal for holding the watch in place to get the most accurate wrist measured heart rate.

The optical heart-rate monitor is automatic when left on, allowing the device to save battery when not in use. The problem is this isn't so smart. We found that even with the watch off, on a table, the heart rate light remained on for a little while before cutting out. That said, battery life wasn't massively affected so it's not a big deal.

The watch can also be bought with an optional heart-rate strap which delivers greater data metrics thanks to that more accurate measurement.

Garmin Forerunner 735XT: Sports tracking

Garmin Forerunner 735XT review

When it comes to the core events of running, cycling and swimming the 735XT has everything covered. Track indoor training using the motion sensors or head outside using the GPS – an ideal option when it comes to pool and open water swimming. But it's the deep data metrics that make this special.

The built-in heart rate monitor can be used for training in zones, or for at-a-glance feedback, but a chest strap still offers more accuracy and even more metrics. When activity trackers started using optical heart rate the serious GPS companies like Garmin and Polar held off, saying chest straps were superior. Then a certain fruit named gadget manufacturer plonked optical heart rate on its first wearable and Garmin folded to the will of the people.

So while the optical heart-rate monitor is there to please everyone, Garmin still offers chest straps for the more serious athlete that wants supreme accuracy and the resultant data.

Garmin Forerunner 735XT review

Heart rate tracking: Garmin Forerunner 735XT against chest strap

With the chest strap in place you can benefit from running dynamics that measure – deep breath – vertical oscillation, ground contact time, cadence, stride length, vertical ratio, ground contact time balance and even an estimated lactate threshold figure, recovery time and VO2 max. If all that lot isn't clear enough, for the less hardcore you can turn on virtual partner and set that to a pace you need to follow – ideal for specific race finish goals.

All that said, when we ran with a chest strap connected to the MapMyFitness app on our phone and the Garmin using optical heart rate the difference was minimal.

Garmin Forerunner 735XT review

Swim tracking is pretty much spot on for length count thanks to the auto stroke detection system. On a 1,000m swim we found it to be one length out in a 50m pool – although that might have just been our pesky fleshy brains miscounting when tired. However if you're planning on stopping and starting you will need to press pause, as this doesn't do it automatically like the Suunto Ambit3 Vertical, for example. Despite the built-in heart rate monitor, you'll need the tri-chest strap to track heart rate as all that water sloshing disables the wrist HR tracking.

Garmin Forerunner 735XT review

When cycling the data is accurate thanks to Garmin GPS smarts, but we'd say that the optical heart-rate monitor can get glitchy here. If you're riding a racer the drop-handlebars can flex your wrist muscles in a way that works the watch off your wrist and down to your hand, we found. Tightening the strap helps sort this but it's verging on uncomfortable, so we opted for the chest strap when out on the bike.

Garmin Forerunner 735XT: Garmin Connect app

Garmin Forerunner 735XT review

The Garmin Connect app is the Marmite of the sports tracker world. Love it or hate it. There are plenty of options to deep dive data but you get a clear at-a-glance top level view that works for beginners too.

However, we suffered some Bluetooth issues with the Connect app (and other Garmin watches) with an Android device. There's no button to sync the watch and phone as it works automatically. While this is done to make it easier, when problems arise you're left without much control to fix them. We even lost a bunch of runs as we had to reset the watch to get it to connect with the app as if for the first time again.

Garmin Forerunner 735XT review

Connectivity issues aside, the app does show off routes clearly with maps and paths plotted out. While data is laid out obviously in graphs, there isn't a great deal to do with that data – it's left to you to decide what it all means. With activity tracker manufacturers like Jawbone investing a lot in apps that translate data into actions, Garmin could do with expanding the app here. It does have a section called Insights but this is largely limited to step focused tips like "walk faster".

Thanks to Garmin's GPS heritage and adventure gadgets there are some nice options for routing. You can save a course to repeat in future or create routes with waypoints that can be followed as you run. This is ideal if you have a specific distance or route with the right hill climbs you want to train on regularly to track progress more clearly.

Then there are the Connect IQ apps that sit on Garmin's own app platform. These range from cool watch faces and Strava live cycling to find-my-car and gym timer apps – there are plenty to pick from. While the platform is limited, it adds a lot to the value of the watch and makes the time between buying and getting bored far longer. This should ultimately keep you using the watch, which is always going to be a good thing for training.

Garmin Forerunner 735XT: Smartwatch notifications

Garmin Forerunner 735XT review

Garmin has got smart notifications right. It just works. Sure, you can't respond but that's not the point. This is primarily a watch for serious training where you ignore most notifications, only using them to keep you aware of anything serious enough to interrupt your attempts at a new personal best.

The watch is able to deliver call alerts, with caller name, text messages, WhatsApp notifications and even emails. You can read most of those right on the watch, excluding emails. Calendar notifications can also be of use when out and about.

Amazon PA: Garmin Forerunner 735XT

Since the watch also acts as a daily activity tracker, you can have movement alerts vibrate to stop you staying too stagnant. This is accompanied by Garmin's red Move bar that grows if you remain still for too long.

Garmin Forerunner 735XT: Battery life

Thanks to the extras on the 735XT and the drop in size from its predecessor, the 920XT, this model tops out at about 24 hours of UltraTrac GPS or 14 hours of pure GPS tracking. Compared the the 50 odd hours of the Fenix 3, suddenly that extra heft doesn't seem so bad. That said most people, even first timers, will finish a triathlon in 14 hours since that's around the cut off point.

It seems Garmin has made this watch with that very specific time in mind. You get a good week of use for daily step tracking, smartphone alerts and heart rate on the wrist. So there's very little to worry about on the charging front.

TAGGED Garmin Sport

How we test


Luke is an AOP Award-winning and APA Award-nominated journalist with over ten years' of experience in technology writing.

He works for The Metro, IdealHome, The Guardian, The Sun, Daily Mirror, Wired, BBC Focus, T3, Stuff, Tech Radar, Recombu, Trusted Reviews and more. 

Luke spent time at the world's best-selling gadget magazine, in charge of news, reviews, and presenting videos for 

He was news editor at Pocket-Lint where he sourced, wrote and edited daily tech news features and reviews.

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