Best triathlon watch 2021: track your swim, cycle and run with these advanced multisport watches

The best triathlon watches for the discerning athlete from Garmin, Polar, Suunto and more

Included in this guide:

The best triathlon watch can help you train more efficiently by measuring performance stats and providing feedback on your progress
(Image credit: Wahoo)

Is the best triathlon watch a must-have? Although it's not essential, monitoring performance and recovery during tri training and races can provide you with a competitive edge over your fellow triathletes. Track your swims, cycles and runs without excessive button pressing using one of these capable wrist wearables.

Triathlon watches are different from the best running watches and definitely from the best fitness trackers. For instance, triathlon watches usually have a dedicated triathlon mode, and some of them can even read heart rate underwater. For even more accurate heart rate readings, pair your tri watch with one of the best heart rate monitors.

Triathlon is a great sport, and if you have been practising even just one of its sport principles before (swimming, cycling or running), it is worth trying. Triathlon challenges your endurance, and since there are so many different race lengths, you can pick one that suits your fitness level the most.

That said, you should take race preparations seriously. If the last time you swam more than 10 metres was in school 20 years ago, it might take you up to 10-12 weeks to get ready for the 700-metre open water swimming leg of a triathlon sprint. Let alone the 20 km cycling and the 5 km running parts, in quick succession after one another.

One of the most common triathlon mistakes is to get your pacing wrong by not knowing which heart rate zone you should train in. A dedicated tri watch can help get that right, as well as many other metrics, in the water, on the bike or on your feet.

Best triathlon watches to buy in 2021

The Garmin Forerunner 945 is the T3's choice for best triathlon watchT3 Approved badge

(Image credit: Garmin)

Best triathlon watch overall

Weight: 50 grams
Battery life: Up to two weeks (Smartwatch mode), up to 36 hours (GPS mode without music), up to 10 hours (GPS mode with music)
Reasons to buy
+ELEVATE HR sensor is accurate, even under water+Sturdy yet light watch case+Accurate GPS
Reasons to avoid
-Lots of redundant features for triathletes

The Garmin Forerunner 945 is the perfect compromise between features and price, whilst not being a compromise at all. Many people will say 'but it looks the same as the Forerunner 935' and you know what? They are right. But whilst the Forerunner 945 has retained the look and feel of the Forerunner 935, in the inside, it has been completely revamped.

For starters, it uses Garmin's new ELEVATE heart rate sensor, which is more accurate, even under water, than the 935's sensor. The Forerunner 945 also uses a new GPS chip that manages battery life better and it is more accurate than its predecessor as well.

The Forerunner 935 didn't have any onboard music storage and wasn't Garmin Pay ready, unlike the Forerunner 945, which is. You won't use any of these features on races, probably, but we can safely assume that you will wear the smartwatch on non-race days, too, where they might come in handy.

The Forerunner 945 also has many of Garmin's latest-gen features, including PulseOx (blood oxygen monitoring), Live Event Sharing, accident detection and assistance, Body Battery energy monitor, training load focus and many more.

Not to mention the built in maps feature, which you can use for navigation as well as to discover local points of interest. Granted, the 1.2" screen is not as detailed as your smartphone, but if you want to break away from the phone screen for a bit and still want to be able to navigate in the same time, the Garmin Forerunner 945 has got your back.

The Polar Vantage M2 is the best Polar watch for triathlonsT3 Approved badge

(Image credit: Polar)

Best cheap triathlon watch

Weight: 45.5 grams
Battery life: Up to 5 days (Smartwatch mode), up to 30 hours (GPS mode)
Reasons to buy
+Buttons-only navigation works great+Plenty of decent sports features and sport modes+Strikes a good balance between style and sportiness+Well-priced
Reasons to avoid
-Usual accuracy issues (nothing major, though)-Not quite enough personalisation options

The more we used the Polar Vantage M2, the more we liked it. This capable tri watch strikes a good balance between style and substance: it has a range of sport and casual ones features and it doesn't look too bad either.

As well as having over 130 sport modes (one of them being triathlon, of course), the Polar Vantage M2 is also capable of automatically detecting your heart rate, swimming style, distance, pace, strokes and rest times while in the pool and it can also track distance and strokes in open water.

Is there a reason why you shouldn't get the Polar Vantage M2? Admittedly, if you need a hardcore tri watch, you might find be better off with a more feature rich watch such as the Vantage V2. But if you can live without the extra tests the latter provides – and dislike touchscreen fitness watches – you are probably better off getting the Polar Vantage M2. 

We pitted the two Vantage watches against each other to find out which Polar wearable is the best triathlon watch: Polar Vantage M2 vs Vantage V2

The Garmin Forerunner 745 is the best (and only) dedicated Forerunner for triathletesT3 Approved badge

(Image credit: Garmin)

Best dedicated triathlon watch

Weight: 47 grams
Battery life: Up to a week (Smartwatch mode), up to 6 hours (GPS mode with music), up to 16 hours (GPS mode without music), up to 21 hours (UltraTrac mode)
Reasons to buy
+A triathlon-focused Forerunner!+Handsome display+Almost identical to Forerunner 945 but lighter and cheaper
Reasons to avoid
-Comparatively short GPS battery life

The Garmin Forerunner 745 is an amazing triathlon watch. It's in the goldilocks-zone in terms of features and price. It is somewhat cheaper than the Forerunner 945 and trims some of its over-the-top-features (sorry, archers) as well as offering more precision, faster and more reliable GPS connection than the cheaper Forerunner 245, especially if you are using your watch for triathlons.

We can go on forever dissecting the many features of the Forerunner 745 but there is no point. You have seen most of them in other Garmin watches already and the main advantage of the Forerunner 745 is not that it brings a lot of new innovation to the table, but that it uses the right blend of previously tried-and-tested hardware and software.

I'm sure we'll see a lot of software updates coming for the Forerunner 745 in the coming months and years so even if you feel like it's not the most precise running watch yet, you can rest assured it will get more and more precise as time goes on. If you are happy with how the hardware looks like/feels on the wrist, we recommend getting the new Forerunner 745, it's a worthy investment.

The only downside is the poor battery life when the GPS is on; if you need a triathlon watch with long GPS life, either get the Forerunner 945 or the Suunto 9 Baro. 

The Coros Pace 2 is the best lightweight triathlon watchT3 Approved badge

(Image credit: COROS)

Best lightweight triathlon watch

Weight: 29 grams (with nylon band)
Battery life: Up to 20 days (smartwatch mode), 30 hours (GPS mode)
Reasons to buy
+Lightweight+Excellent screen+Plenty of sensors
Reasons to avoid
-Can't sync workout data with Google Fit/Apple Health-Would be great to customise widgets on the watch

To put it in perspective how pretty the screen is, during testing, I often caught myself looking at the widgets of the Coros Pace 2 for no reason whatsoever. Better still, the watch is comfortable to wear thanks to its small form factor, making it possible to wear it for sleeping to get better recovery results.

As well as being able to track the usual metrics, the Coros Pace 2 can also measure running power on the wrist without any external sensors, much like the Polar Vantage V. But unlike the Vantage V, the Pace 2 hasn't got a touch screen so if you like tapping your wrist, opt in for the Polar.

The battery life of the Pace 2 delivers big time. Make sure you dust that charger cable off every now and then as the Coros Pace 2 won't need to be charged more than once every other week. The battery life is not 'indefinite' like in the case of the Garmin Instinct Solar but pretty good for a watch so light and compact.

The Pace 2 is the lightest tri watch on the market, at least of the lot that I would recommend using. It weighs around 30 grams (with the nylon band) so it's barely detectable on the wrist. The perfect tri watch for those who don't like wearing a watch.

The Wahoo Elemnt Rival is a hardcore tri watch for elite athletesT3 Approved badge

(Image credit: Wahoo)

The best triathlon watch for die-hard athletes

Weight: 53 grams
Battery life: up to 14 days (Smartwatch Mode), up to 24 hours (GPS or HR Mode)
Reasons to buy
+Lightweight+Extremely easy to set up and use+Clear data screens+Touchless Transition tech
Reasons to avoid
-Less features-packed than rivals-No navigation feature for instance-Sensitive to colour specification

Although not as rugged as Garmin’s Fenix range (or anything from the Suunto catalogue for that matter), nor as good as a general fitness watch as, say a Fitbit Versa 3, the Wahoo Elemnt Rival majors on its swim/bike/run focus.

If you are someone who regularly enjoys those pursuits, individually or in triathlon form, Wahoo’s smartwatch delivers a bucketload of data in a way that requires very minimal interaction with the tech, allowing you to focus on performance with only the cursory glance at the watch face.

The Touchless Transition is an excellent innovation and works very well, while the fact data is seamlessly handed over to other Wahoo bike computers will please anyone who is already invested into the ecosystem.

The Polar Vantage V2 is the best tri watch for recovery and performance tests

(Image credit: Polar)

Best triathlon watch for recovery and performance tests

Weight: 76 grams
Battery life: 7 days (Smartwatch mode), 25 hours (GPS mode, up to 170 hours with battery saver on)
Reasons to buy
+Sleek premium design+Large screen with amazing resolution+Ultra long battery life+Premium feel
Reasons to avoid
-You'll need Suunto Smart Heart Rate Belt and Suunto Smart Sensor to track heart rate under water-No NFC or music storage-Premium price tag

The Polar Vantage V2 might lack some of the more casual features you'd expect to see in a top-notch triathlon-cum-fitness watch, such as on-board music storage and maybe even NFC, but truth to be told, the Vantage V2 is for the hardcore crowd and they might not care all that much about these filthy casual frivolities anyway.

The Polar Vantage V2 is a watch of many qualities. Its built quality is excellent and definitely a step up from original Polar Vantage V. It has loads of useful tests and data for serious runners and cyclists to better their form and get ready for races more efficiently. Better still, most of the tests and data provided by the Vantage V2 can't be found elsewhere, making it all the more appealing for the information thirsty athletes.

It would have been great to see some improvements to the user interface and especially the navigation. Touch controls are still a bit laggy, although the screen feels a bit more responsive than the one found on the Vantage V.

I would certainly recommend the Polar Vantage V2 to anyone who would like to take their athletic performance to the next level: there aren't many wrist-wearables that provide quite as much data as this one.

The Suunto 9 Baro Titanium is rugged and ready to battle the elementsT3 Approved badge

(Image credit: Suunto)

Best triathlon watch for ruggedness

Weight: 76 grams
Battery life: 7 days (Smartwatch mode), 25 hours (GPS mode, up to 170 hours with battery saver on)
Reasons to buy
+Sleek premium design+Large screen with amazing resolution+Ultra long battery life+Premium feel
Reasons to avoid
-You'll need Suunto Smart Heart Rate Belt and Suunto Smart Sensor to track heart rate under water-No NFC or music storage-Premium price tag

If you need looooong battery life, you'll need the Suunto 9 Baro Titanium: it can last up to 170 hours in Tour mode which is the most aggressive battery saver option on the watch. Granted, you probably won't use this mode all that often, considering the watch does not much else apart from tracking your position with an 'OK' precision, so no wrist heart rate, Bluetooth or vibration.

The Titanium version of this endurance athlete favourite watch might not be cheap but it features a titanium bezel and sapphire crystal glass for added ruggedness. The case is also water rated to 100 ATM so you can easily swim in it. That said, it can't read heart rate on the wrist underwater without external sensors but it can track loads of other metrics such as swim pace and distance, stroke rate, count and type, and even SWOLF.

From a build quality point of view, the Suunto 9 Baro Titanium feels closer to dive watch than a running watch, meaning it is more robust and certainly heavier than the Garmin Forerunner 945, for example. People with smaller wrists might not appreciate the size of the watch but should your wrist circumference be large enough, you'll sure appreciate the large, high resolution display which is in fact more detail-rich than most other fitness wearables on the market today.

The Garmin Fenix 6 Pro Titanium is one of the most overpowered multisport watches that is okay to useT3 Approved badge

(Image credit: Garmin)

Best smartwatch for triathlons

Weight: 49 grams (case only)
Battery life: Up to 14 days (smartwatch mode), up to 36 hours (GPS mode), up to 10 hours (GPS with music)
Reasons to buy
+Clear display+Widget user interface is brilliant+Built-in music storage + Garmin Pay
Reasons to avoid
-Bit on the heavy side

The Garmin Fenix 6 Pro is a great smartwatch for anyone who loves the Great Outdoors and since triathlon races tend to be held outdoors, it is also great for triathletes, too.

Garmin managed to improve on the formula that made the Fenix 5 Plus so great, further enhancing the battery life and also tweaking the user interface, which is now way easier to glance over, thanks to the widget view.

If anything, the Fenix 6 Pro is more rugged than light, but it is far from being too heavy, the Titanium version is also 11 grams lighter than the steel version, making it on par with other smartwatches on this list.

It also has a multisport mode which makes switching between sport modes as easy as pressing a button. The Fenix 6 Pro also has all the functions we already mentioned above in the Forerunner 945 review, but in a more stylish package.

The Polar Vantage M is a budget friendly option for price conscious triathletesT3 Approved badge

(Image credit: Polar)

9. Polar Vantage M

Best cheap tri watch for athletes on a very tight budget

Weight: 28 grams (case only)
Battery life: Up to 5 days (smartwatch mode), up to 30 hours (GPS mode)
Reasons to buy
+Light as a feather+Good price point+Decent battery life in GPS mode
Reasons to avoid
-Hardened-plastic lens-Not so decent battery life in smartwatch mode

The Polar Vantage M might be almost £200 cheaper than the Vantage V, but it you aren't too keen on the running power metric and don't often do ultra-marathons, you are probably better off with the former.

The Polar Vantage M is light – the case is only 28 grams – and has a decent sized 1.2" screen, too, with a 240 x 240 pixels resolution. You can choose from a range of funky-coloured straps as well, our personal favourite is the lime green one, which will make you stand out from the sea of black multisport smartwatch wearers.

The Vantage M supports advanced swimming metrics and automatically detects your heart rate, swimming style, distance, pace, strokes and rest times. Distance and strokes get tracked also in open water swimming.

One advantage of the Polar Vantage series is the Precision Prime sensor technology, which uses 9 sensors to measure your heart rate, plus has 4 additional skin-contact sensors, so it knows when the watch is in the correct place for precise measurement.

Among other features, the Polar Vantage M also has a multisport mode which makes switching between sports easy as pie.

the Garmin Forerunner 935 is still worth consideringT3 Approved badge

(Image credit: Garmin)

10. Garmin Forerunner 935

A Forerunner worth considering

Weight: 49 grams
Battery life: GPS mode – up to 24 hours, GPS tracking in UltraTrac mode – up to 50 hours, Smartwatch mode – up to 14 days
Reasons to buy
+Dedicated triathlon sport mode+Good battery life+Screen size on par with newer watches
Reasons to avoid
-Not cutting edge tech anymore

What can we say? The Garmin Forerunner 935 is still a very decent multisport watch. It tracks position precisely, has loads of great functions (with probably many more rolled out later as firmware update) and now that the Forerunner 945 has been released, the price is on point, too.

It might pick up GPS signal a bit slower than the Forerunner 945 and might not be as precise as that and by getting it you might miss out on the new features mentioned in the Forerunner 945 review.

It also uses Garmin's last gen heart rate sensor, which is not imprecise, but definitely not as accurate as the ELEVATE sensor.

What the Forerunner 935 has, though, is built-in barometer, altimeter and electronic compass as well as features like training load and good battery life.

All for a reasonable price.

Train old school Timex Ironman Classic 30T3 Approved badge

(Image credit: Timex)

Special mention: Timex Ironman Classic 30

One for the purists

Lens material: Acrylic
Case size: 1.5" (38 mm)
Display resolution: N/A
Weight: 23 grams
Battery life: Forever
Reasons to buy
+Reliable time keeping device
Reasons to avoid
-Literally does nothing else but tracks time

Want a watch that will practically last forever and has no learning curve either? Not interested in advanced metrics, heart rate or GPS positing? You literally just want to track time and don't want to spend a fortune on a smartwatch? The Timex Ironman Classic 30 is for you.

What you'll get for the price is features like lap timer, alarm, back light and stop watch. The watch also has shatter-resistant acrylic window lens and a round high-performance and durable resin case with digital display.

The Timex Ironman Classic 30 is also water resistant to 10 metres, and you probably won;t dive too deep into water with it, so it all checks out to us!

Best triathlon watch: how to choose the best triathlon watch for you?

A good tri watch has many extra features on top of the ones a regular running smartwatch has. For one, it needs to be waterproof; otherwise, it would be quite hard to wear it all the way through a triathlon race. The main criteria are as follows:

Battery life: a triathlon race can last for anything from a couple of hours to a couple of days, but you are looking at 3-4 hours of race time on average. The good tri watch should be able to last at least 6-8 hours in GPS mode to make sure it won't die on your wrist just before the end of the race, losing all the data and your bragging rights for later, having no proof that you completed the race. The Coros Apex, for example, can last up to 100 hours in GPS mode, and the Suunto 9 Baro, up to 120 hours.

Water-tight construction: as mentioned above, it would be rather difficult to track swimming with a watch that is not water-rated to at least 50 metres. The best triathlon watches are not only swim-proof; they can also measure heart rate on the wrist under water and track advanced swimming metrics, too, like stroke count, pace and SWOLF.

Multisport transition: it is also important to be able to switch between sports modes without excessive button pressing. You will be quite preoccupied with taking your wetsuit off and putting your cycling gear on after getting out of the water, let alone trying to find the right menu setting for switching from tracking swimming to tracking cycling. Most top tier smartwatches offer one-button multisport transition and even have a dedicated triathlon mode for added convenience.

Fit and comfort: races last for a few hours, and you don't want to feel uncomfortable, adjusting the watch on your wrist every two minutes because it's giving you all the wrong HR readings. To achieve a comfortable fit, you would need a flexible silicone strap and a smooth case material. Watches like the Polar Vantage V and the Suunto 9 Baro have a curved design that makes fitting the watch snugly around your wrist easier.

Ruggedness: you don't want your new tri watch to break after accidentally falling off your wrist or get scratched after bumping it into your bike's handlebar, do you? Many top tri watches come with Gorilla Glass or Sapphire crystal lenses and sturdy casing. The Garmin Fenix 6 Pro Titanium has a titanium housing, comes with a Sapphire crystal lens on the top and weighs 49 grams (case only).

What watch do pro triathletes use?

According to an article on, the top 15 pro men finishers at Kona 2019 mainly used Garmin and Polar watches. Apart from the winner, Jan Frodeno, who now works with Wahoo and uses a Wahoo Rival, according to a press release from Wahoo: "RIVAL is already being used by some of the world’s best triathletes, including Ironman World Champion Jan Frodeno, American Ironman World Record holder Heather Jackson, and two-time Olympians Alistair and Jonny Brownlee."

Although not famous for his triathlon feats, but Eliud Kipchoge uses a Coros Pace 2, an excellent watch that can also be used for triathlons as well (not to mention, it's featured on this best tri watch list).

Matt Kollat
Matt Kollat

Matt is a fitness fanatic (a.k.a. fitness and nutrition writer) who's been rambling on about all things health and fitness for over two years now here at T3. His achievements include a short-lived fitness podcast called Fit Mentality Podcast and being a judge on the Fit&Well Awards 2021. In his free time, he works out at home, runs, cycles and loves a good ol' walk around the city. He writes about general fitness stuff, fitness tech, workouts, workout gear/equipment, nutrition and much, much more.