Best triathlon watch 2021: track your swim, cycle and run with these advanced multi-sport smartwatches

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

Best triathlon watch
(Image credit: Wahoo)

Looking for the best triathlon watch? Come right this way. The below GPS multisport watches are the cream of the crop, the most advanced triathlon wearables from leading brands including Garmin, Polar, Suunto and Coros. Track your swims, cycles and runs without excessive button pressing using one of the fitness smartwatches on this list below.

Triathlon watches are different from the best running watches and definitely from the best fitness trackers as these multisport watches usually have a dedicated triathlon mode and some of them can even read heart rate under water. For ultimate heart rate reading accuracy, get one of the best heart rate monitors and pair them with these triathlon watches. 

Triathlon is a great sport and if you have been practising even just one of its sport principles before (either 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.

Saying that, 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 each other.

One of the most common triathlon mistakes is to get your pacing wrong, by not knowing which heart rate zone you train in. That's where a good (best, even) triathlon watch can come super handy, a wearable that monitors your heart rate in real time, as well as your pace, position and loads more metrics, in the water, on the bike and on your feet, running.

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 a 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 sport 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. In order to achieve a comfortable fit, you would need a flexible silicone strap as well as 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 to 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, like the Garmin Fenix 6 Pro Titanium, which has a titanium housing, comes with a Sapphire crystal lens on the top and only 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 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).

The best triathlon watches, in order of preference

best triathlon watch: Garmin Forerunner 945T3 Best Buy badge

(Image credit: Garmin)

Garmin Forerunner 945

Light yet versatile multisport watch with excellent sensors

Lens material: Gorilla Glass
Display size: 1.2" (30.4 mm)
Display resolution: 240 x 240 pixels
Weight: 50 grams
Battery life: GPS mode with music – up to 10 hours, GPS mode without music – up to 36 hours, Smartwatch mode – up to 2 weeks
Reasons to buy
+Completely revamped hardware+Uses Garmin's new ELEVATE HR sensor+Garmin Pay ready+Gorilla Glass+Sony GPS chip
Reasons to avoid
-Feels a bit plasticy

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, 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.

• Read our full Garmin Forerunner 945 review here

best triathlon watch: Polar Vantage M2T3 Approved Badge

(Image credit: Polar)

Polar Vantage M2

Lightweight tri watch for the style-conscious triathlete

Lens material: Hard-coated PMMA laminated lens
Display size: 1.2" (30.4 mm)
Display resolution: 240 x 240 pixels
Weight: 45.5 grams
Battery life: Up to 30 hrs in training mode (GPS and wrist-based heart rate) or up to 5 days in watch mode with continuous heart rate tracking
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. 

• Read our full Polar Vantage M2 here

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

best triathlon watch: Garmin Forerunner 745T3 Approved Badge

(Image credit: Garmin)

Garmin Forerunner 745

Garmin Forerunner 945 Lite

Lens material: Gorilla Glass
Display size: 1.2" (30.4 mm)
Display resolution: 240 x 240 pixels
Weight: 47 grams
Battery life: Smartwatch mode: up to a week, GPS mode with music: up to 6 hours, GPS mode without music: up to 16 hours, UltraTrac mode: up to 21 hours
Reasons to avoid
-GPS battery life is not great

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. 

• Read our full Garmin Forerunner 745 review here

best triathlon watch: Garmin Fenix 6 Pro TitaniumT3 Approved Badge

(Image credit: Garmin)

Garmin Fenix 6 Pro Titanium (47 mm case)

Ruggedness meets precision in a premium package

Lens material: Sapphire Crystal
Display size: 1.3" (33 mm)
Display resolution: 260 x 260 pixels
Weight: 49 grams (case only)
Battery life: GPS mode – up to 36 hours, GPS with music – up to 10 hours, Smartwatch mode – up to 14 days, Battery saver watch mode – up to 48 days
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.

• Read our full Garmin Fenix 6 Pro review here

best triathlon watch: Suunto 9 BaroT3 Approved Badge

(Image credit: Suunto)

Suunto 9 Baro

An ultra-marathon favourite

Display size: 1.4" (35.56 mm)
Display resolution: 320 x 320 pixels
Weight: 81 grams
Battery life: Training mode with GPS – up to 120 hours, With 24/7 tracking and mobile notifications – up to 7 days, Time mode – up to 14 days
Reasons to buy
+Large screen with brill resolution+Ultra long battery life+Premium feel
Reasons to avoid
-Only measures heart rate under water using a chest strap-Might be too big for people with smaller wrists

The Suunto 9 Baro wins on battery life, lasting up to 120 hours in Ultra mode. Saying this, you probably won't use the Ultra mode all that often, since in this mode, the Sunnto 9 Baro does not much else apart from tracking your position with an 'OK' precision, so no wrist heart rate, bluetooth or vibration.

But even in performance mode, the Suunto 9 Baro can last up to 24 hours, more than enough for majority of triathlon races you will likely to attend. 

As for build quality, the Suunto 9 Baro feels closer to diving watch than a running watch, meaning it is more robust and heavier than the Garmin Forerunner 945, for example. For people with smaller wrists, this might be a deal breaker, since for accurate heart rate tracking, the watch needs to sit on your wrist snugly. And for that, you'll need some wrist circumference wearing the Suunto 9 Baro.

The watch might be a bit big but at least the front is filled with the display, and a high resolution display that is. The resolution is 320 x 320 pixels, the highest on this list.

One downside of the Suunto 9 Baro is that it can't track heart rate on the wrist under water. It tracks loads of other metrics, though, including swim pace and distance, stroke rate, count and type, and even SWOLF.

Oh, and this watch has a touch screen, which feature is disabled in exercise mode (much like the Polar Vantage M).

best triathlon watch: Coros Pace 2T3 Approved Badge

(Image credit: COROS)


The lightest triathlon watch on the market today

Weight: 29 grams (with band)
Battery life: 30 hours in GPS mode, up to 20 days considering average usage
Reasons to buy
+Lightweight+Excellent screen+Plenty of sensors
Reasons to avoid
-Can struggle to pick up GPS signal

• Buy the Coros Pace 2 directly from Coros

All things considered, the Coros Pace 2 is a great triathlon watch, despite the glitchy GPS performance. The screen is so nice to look at I often caught myself pursuing the widgets for no reason whatsoever. The Pace 2 is comfortable to wear and since it can't track sleep or recovery, you won't feel the need to wear it for your sleep either. If you want a good sleep tracker, check out the new Fitbit Sense (that might struggle with triathlon tracking, though).

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.

Should the GPS performance be amended at some point, I will wholeheartedly recommend the Coros Pace 2 for all runners and triathletes and those purists who don't care about arbitrary casual features and would like to use a multisport watch for sports and not as an ornament on the wrist.

• Read our full Coros Pace 2 review here

best triathlon watch: Wahoo Elemnt RivalT3 Approved Badge

(Image credit: Wahoo)

Wahoo Elemnt Rival

Hardcore sports data watch

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.

• Read our full Wahoo Elemnt Rival review here

Best triathlon watch: Polar Vantage MT3 Approved Badge

(Image credit: Polar)

Polar Vantage M

Not just for runners

Lens material: Hard-coated PMMA laminated lens
Display size: 1.2" (30.5 mm)
Display resolution: 240 x 240 pixels
Weight: 28 grams (case only)
Battery life: Training mode with GPS – up to 30 hours, Smartwatch mode – up to 5 days
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.

best triathlon watch: Garmin Forerunner 935T3 Approved Badge

(Image credit: Garmin)

Garmin Forerunner 935

A still capable fitness watch for a good price point

Lens material: Chemically strengthened glass
Display size: 1.2" (30.5 mm)
Display resolution: 240 x 240 pixels
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.

Best triathlon watch: Coros ApexT3 Approved Badge

(Image credit: Coros)

Coros Apex (46 mm case)

A solid offering from a disruptor brand of the fitness smartwatch world

Lens material: Sapphire Glass
Display size: 1.8" (46 mm)
Display resolution: 240 x 240 pixels
Weight: 55.3 grams
Battery life: Full GPS mode – up to 35 hours, UltraMax GPS mode – up to 100 hours, Smartwatch mode – up to 30 days
Reasons to buy
+Huge and bright screen+Low price point+Monster battery life
Reasons to avoid
-Turn dial takes time to get used to

Coros might be a brand some old-school sportspeople are not overly familiar with, but you might want get familiar with the name sooner rather than later. The Chinese company has exploded into the fitness smartwatch scene recently with their quality products, the Apex being the most sophisticated version of the lot.

Naturally, they offer the same (and sometimes better) specs as models with a way heftier price tag on the market, but unlike many other Chinese manufacturers, Coros' offers are actually high-quality and definitely worth the money you invest in them.

The Coros Apex stands out from the crowd with its seriously HUGE screen and extremely long battery life. The former is a whopping 1.8" (46 mm) display hidden under a Sapphire crystal lens with a resolution of 240 x 240.

As for battery life, the Coros Apex can last up to 100 hours in UltraMax mode. In this mode, for every 120 seconds, the GPS is switched on for 30 seconds, then Coros' Intelligent Stride algorithm, along with motion sensors, will kick in for the remaining 90 seconds.

The turn dial does take a minute or two to get used to but once you have done so, it's intuitive enough to use and makes switching between screens as easy as turning a dial. Like, literally.

best triathlon watch: Timex Ironman Classic 30T3 Approved Badge

(Image credit: Timex)

Special mention: Timex Ironman Classic 30

Can't go wrong with this

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

• Buy the Timex Ironman Classic 30 on Amazon

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!