Best Ironman Triathlon Watches Compared

Last updated: September 7, 2021

GPS Running Watch / Best Ironman Triathlon Watches Compared

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The Ironman Triathlon is one of the most enduring endurance events in the world.

A 2.4-mile swim, a 112-mile bicycle ride and a marathon 26.22-mile run. As you can imagine that’s going to take a while to do. Even the legend, Jan Frodeno who is a 3-time winner of the Ironman Championships has a record time of 7:35:39.

Having a watch that has a long battery life is absolutely paramount. Of course, durability and features are important too. We’ve compiled some of the best watches for the Ironman triathlon below to help you make an informed decision.

Best Overall
Garmin Forerunner 945
Garmin Forerunner 945
For Half-Ironman
Garmin Forerunner 745
Garmin Forerunner 745
Best Value
Polar Vantage M2
Polar Vantage M2
Full Aluminium
Polar Vantage V2
Polar Vantage V2
Most Affordable
Coros Vertix
Coros Vertix

Best Triathlon Watches For Ironman Compared & Reviewed

We’ve reviewed some of the best triathlon watches below with the purpose of keeping the Ironman triathlon in mind. Needless to say that these can be used for any other triathlons as well.

1. Garmin Forerunner 945

Key Features

  • 50g (1.76oz)
  • Water-resistant up to 50m
  • 336 hours (14 days) on smartwatch mode
  • 36-hour battery life with GPS (not with music)

Reasons to buy

  • Ultra-long battery life
  • Complete smartwatch features
  • Specialized triathlon features
  • Professional-level performance metrics
  • Responsive training plan

Reasons to avoid

  • Expensive
  • Aesthetics are not the best

For many people, the first watch that comes to mind when you say “premium triathlon watches” would be the Garmin Forerunner 945.

Design-wise, it may not be the best, at least compared to modern smartwatches today. The case and band look quite plasticky, making it seem less durable than it actually is. The huge 47mm screen is scratch-resistant, with a special transflective display technology to make it easier to see under sunlight.

However, don’t let its looks fool you: the Forerunner 945 is one of the best Ironman Triathlon watches out there.

When it comes to sports performance, this watch is a legit beast. It has ten sensors that measure all the relevant physical metrics necessary for your Ironman Triathlon, from heart rate to heat to altitude-adjusted VO2 Max levels. 

With this data, the Forerunner 945 can provide training feedback through training statuses, training effects, and training load metrics. It can even craft you a personalized training program with its adaptive Garmin Coach feature.

Running is a crucial feature in Ironman Triathlons. This watch has specialized features designed to improve how you run: running dynamics and performance condition analytics will tell you everything you need to know, from pace to ground contact time.  Swimming is another essential aspect of the triathlon, and like other Garmin watches, the Forerunner 945 has no problems handling shallow swimming sessions.

Aside from that, there are general sports features such as on-screen workouts, daily suggestions, music download, multiple navigation systems, touchless pay, and more. All this on 14-days of battery life, more than enough for any training or competition.

If you’re serious about winning the next Ironman Triathlon, the Garmin Forerunner 945 is the watch for you.

2. Garmin Forerunner 745

Key Features

  • 30g (1.06oz)
  • Water-resistant up to 50 meters
  • 16 hours battery life with GPS enabled
  • 168 hours battery life on regular mode
  • Connects via Bluetooth and WiFi

Reasons to buy

  • Accurate on-board GPS
  • Supports Spotify Premium
  • Active Zone feature can optimize your runs
  • Heart rate variation display during navigation
  • Fitness and workout push notifications

Reasons to avoid

  • Extremely short battery life with GPS enabled if you’re listening to music which is 6 hours.

A step below the Forerunner 945, the Garmin Forerunner 745 is made for those who want serious firepower on a lower budget.

And it’s not like it sits perpetually in the shadow of the Forerunner 945. This model actually has some advantages against the 945. For one, we like the Forerunner 745’s aesthetics better. It has a smaller case, thinner bezels, and a sleeker overall design that fits better on individuals with smaller wrists.

In terms of performance, the Forerunner 745 won’t back down. Aside from the typical sports watch features, it also contains the Forerunner 945’s most crucial elements: the same ten sensors, training feedback analytics, specialized running tools, and the adaptive Garmin Coach.

Surprisingly, it even has features that are not in the 945. There’s a feature called Race Predictor that uses your fitness data and training history to predict how well you’ll do in the actual race. There’s also a Cycling Power program that aims to help you optimize your energy expenditure during your rides.

You also get full smartwatch functionality. You can download music, use multi-network navigation, pay touchless, and even utilize safety measures that will broadcast your location in case something goes wrong.

Although the battery life is a full step below the Forerunner 945, it’s still one of the longest on the list, lasting about one week before needing a charge.

Overall, the Garmin Forerunner 745 is a sleeker, more compact, and more affordable version of the Forerunner 945 that still delivers many robust features.

3. Polar Vantage M2

Key Features

  • 30g (1.06oz)
  • Water-resistant up to 50 meters
  • Bluetooth and WiFi connectivity
  • 12 hours battery life on GPS mode
  • 144 hours (6 days) on regular mode

Reasons to buy

  • Good battery life
  • Sharp aesthetics
  • Smart refueling assistant
  • Wellness, recovery, and stress management
  • Triathlon performance sensors and features

Reasons to avoid

  • No touchless payment system

With a minimalist and far fancier look than both Garmin watches above, the Polar Vantage M2 packs a serious set of tools to help you win your next Ironman without burning as big a hole in your pocket.

In terms of looks, the Vantage M2’s aesthetics are on point. The ultra-thin bezels and wide scratch-resistant glass make this watch look significantly more spacious than the previous Garmin, even though they have the same screen size. It also has an understated design that makes it look elegant without losing the serious edge.

Function-wise, the Vantage M2 may not be as diverse as the Garmin models above, but it still has a solid set of features that can help you with your goal.

It features professional-level sensors to track heart rate, calories, training load, and more. It also has sports-specific features that will up your Ironman Triathlon experience: a running program, a dedicated swimming tracker, and even integrated settings for sensor-based bicycles. 

One of its standout features is the FuelWise program, which uses your data to let you know the optimal refueling times – perfect for whatever Ironman Triathlon phase you’re facing. There’s also a dedicated rest and recovery module, personalized adaptive workouts, and a stress management tool called Serene.

Aside from that, it has a full set of smartwatch features such as notifications, weather, music controls, and decent 1-week battery life. If you’re willing to forgo touchless payment, the Polar Vantage M2 is a watch that performs as great as it looks.

Though with the battery life on this watch, if you’re using the GPS mode you might not finish your Ironman triathlon depending on the time, however it would definitely be suitable for a Half-Ironman triathlon. Though if you don’t need GPS mode, which usually you don’t for Ironman then you should be fine with the regular mode.

4. Polar Vantage V2

Key Features

  • 52g (1.8oz)
  • Water-resistant up to 100m
  • 40-hour battery life in GPS mode
  • 168-hour battery life in smartwatch mode

Reasons to buy

  • Feature-packed
  • Has basic smartwatch functions
  • Great performance metrics monitoring
  • Offers triathlon-oriented features and modules
  • Durable aerospace aluminum casing

Reasons to avoid

  • Quite expensive
  • The touchscreen can be laggy
  • Doesn’t have contactless pay

Typical of Polar watches, the Polar Vantage V2 looks simple and modern, with a minimalist aesthetic that doesn’t detract from its capable aura.

The Vantage V2 doesn’t sacrifice looks for durability. Its scratch-resistant watch face is framed by ultra-thin bezels and protected by an attractive aerospace aluminum casing. A true multi-sport watch, it’s also water-resistant up to 100 meters, allowing you to wear it at every phase of the Ironman Triathlon.

That said, while the display certainly looks attractive, the touchscreen can sometimes be laggy, which could cost you a few seconds in important runs.

When it comes to features, the Polar Vantage V2 has distinctly Triathlon-oriented modules and programs.

It has performance tests in running and cycling sports, where you can compare your results to other athletes and use them as a baseline for improvement. It also has special monitoring and analytics specifically for swimming metrics.

In addition to that, the Vantage V2 has other features that can aid your physical conditioning and performance, such as training load, rest and recovery, smart fueling, and altitude monitoring modules, just to mention a few.

It has all the basic smartwatch capabilities except for contactless pay. Battery life is pretty good, lasting up to 168 hours on a single charge.

Although it costs and functions similarly to the Garmin Forerunner 745, the Vantage V2 looks smarter – although it loses in terms of smartwatch functionality.

5. Coros Vertix

Key Features

  • 77g (2.72oz)
  • Water-resistant up to 150m
  • 1,080-hour battery life in regular mode
  • 60-hour battery life in GPS mode

Reasons to buy

  • Extreme durability
  • Longest battery life on the list
  • Excellent GPS and altimeter features
  • Basic sports training and workout module
  • Outstanding altitude-related physical metrics

Reasons to avoid

  • Expensive
  • Fit may be awkward for some
  • No rest and recovery modules
  • No basic smartwatch features

Made to conquer the outdoors, the Coros Vertix can easily take you from start to finish and back again with its ultra-durable casing and monster battery life.

A true adventure watch, the Vertix was specially designed with durability in mind. Its scratch-proof screen is made of sapphire glass with a diamond-like coating. The case and bezels are made of titanium, making them extremely strong but still lightweight. It’s also the only GPS watch that is water-resistant up to 150 meters in depth.

The overall look might be a little bulky for some, but it doesn’t look out of place in the GPS watch category.

One of Vertix’s main features is battery life. With an incredible 45 days (1,080 hours) of battery life, it’s by far one of the longest-lasting watches on this list – certainly more than enough for an Ironman Triathlon.

When it comes to features, the Coros Vertix doesn’t disappoint. It has an onboard GPS that can function even in the harshest environments. It also has a built-in altimeter and various physical sensors.

However, it does have limited multi-sports options. While you still get sports profiles, you need to download the Coros Training app to customize your workouts and training loads. It also doesn’t offer many physical performance sensors for general users, nor does it have even the most rudimentary smartwatch features. At this price point, we think this is something that could be improved.

When talking about durability, adventuring, and mountaineering features, the Coros Vertix shines. It may not offer the same multidisciplinary depth as other more generalist triathlon watches, but it’s undoubtedly a great companion to the Ironman Triathlon.

6. Suunto 9 Baro Titanium

Key Features

  • 76g (2.68oz)
  • Water-resistant up to 100m
  • 168 hours (7 days) battery life in full GPS
  • 336 hours (14 days) battery life in normal mode
  • Bluetooth and ANT+ connectivity

Reasons to buy

  • Long battery life even with GPS on
  • Plenty of multi-sports features
  • Excellent outdoor navigation features
  • Rest and recovery modules
  • Specialized profiles for running, cycling, and swimming

Reasons to avoid

  • Not lightweight
  • No smartwatch functions
  • Size might make for an awkward fit for some

When it comes to Ironman Triathlons, it’s important to have something for various terrains. After all, at least two of the events will be done on dry land. Luckily, the Suunto 9 Baro Titanium is here to the rescue.

Like most Suunto watches, the 9 Baro Titanium is built like a tank. It’s thick and chunky in a way that gives it an aggressively outdoor appearance, although it does manage to tone it down a little with the minimalist design and subdued color schemes.

Runners looking to get this watch should be prepared for its size and weight, though. Even though it’s relatively light for its size, you can still feel that it’s there on your wrist.

If that doesn’t sound too bad for you, few outdoor watches are better than the Suunto 9 Baro Titanium. Not only is it made to be ultra-durable, but it also has an excellent navigation system with its onboard GPS, compass, altimeter, and weather sensor. Whatever the terrain, you can be sure that you’re prepared for all the possibilities.

It has more comprehensive sports and performance functions than the Vertix Coros, which includes swimming and cycling. It even has stress and recovery module training functions and 24/7 monitoring. However, what it doesn’t have are smartwatch functions, as this isn’t a smartwatch at all.

Battery life is one of the 9 Baro Titanium’s strongest suits. With GPS disabled, it can last up to 336 hours (14 days), but even with continuous GPS tracking, it has enough power to last 168 hours (7 days.) It also has advanced battery-saving features to help it last longer.

If you don’t mind the size and the lack of smartwatch features, the Suunto 9 Baro Titanium is a premium multi-sports outdoor watch that you can bring with you to the Ironman Triathlon.

7. Garmin Fenix 6 Pro Titanium

Key Features

  • 83g (2.9oz)
  • Water-resistant up to 100m
  • 336 hours (14 days) battery life in smartwatch mode
  • 36 hours (1.5 days) battery life on GPS mode
  • 10 hours battery life with GPS and music

Reasons to buy

  • Plenty of features
  • Good battery life with GPS disabled
  • Full smartwatch functions
  • Sports and performance modules
  • Professional-level training sensors and programs

Reasons to avoid

  • Very expensive

With a generous storage capacity and a wide range of sports performance features, the Garmin Fenix 6 Pro Titanium is for hardcore athletes who are serious about winning the next Ironman Triathlon.

We know that Garmin watches don’t come cheap, but the Fenix 6 Pro Titanium, in particular, is more expensive than most. With a mean, rugged look, its aesthetic appeal alone can make anyone feel like a major contender to an Ironman – and honestly, for the price you’re paying for this model, you should be.

For triathlon-specific events, it features a ton of preloaded sports apps that include swimming, running, and cycling, as well as a special pace guidance technology called PacePro.

It has general performance features that can help condition your body and optimizes your output, such as a body energy monitor, an environment-adjusted VO2 Max sensor, a smart recovery advisor, and lots more. It also has dozens of features for other physically demanding activities, such as mountain climbing, mountain biking, and winter sports.

Unlike most outdoor watches, the Fenix 6 Pro Titanium is also a fully functioning smartwatch that you can use to make calls, receive notifications, store music, and pay wirelessly. It can last up to 336 hours (14 days) in smartwatch mode, but with GPS and music, this dwindles to a mere 10 hours.

Nevertheless, the Garmin Fenix 6 Pro Titanium is a serious multidisciplinary watch that will condition you for the Ironman Triathlon and give you everything you need for a great time.

8. Coros Pace 2

Key Features

  • 35g (1.23oz)
  • Water-resistant up to 50m
  • 480-hour (20 days) battery life in regular mode
  • 60-hour battery life in UltraMax GPS mode
  • 30-hour battery life in full GPS mode

Reasons to buy

  • Accessible price
  • Convenient controls
  • Accurate onboard GPS
  • One of the lightest GPS watches
  • Strong physical metric sensors

Reasons to avoid

  • No smartwatch features
  • Somewhat limited performance metrics

One of the lightest GPS watches around, the Coros Pace 2 looks the part: simple, sleek, and effective. It may feel a bit plasticky for some, but it’s a conscious design choice that eliminates extra weight.

In terms of accessibility, the Pace 2 is the only watch on the list that emphasizes convenience. You can cycle through multiple functions with just one finger so that you won’t have to fumble around with buttons during your workouts.

It has distinctly running-oriented features, with a powerful GPS program that can map your route and provide a comprehensive analysis of your pace, distance, steps, and running power. It also utilizes an activity-adjusted heart rate algorithm for different kinds of runs.

The Pace 2 also has multiple sports modes that include cycling, swimming, and general fitness functions such as muscle heatmap and personal training.

When it comes to battery life, the Pace 2 is pretty good. It can last up to 480 hours (20 days) with continuous heart rate and sleep monitoring. With full GPS functions enabled, it has enough power to last 30 hours, which is rather impressive compared to other watches on this list.

Light but powerful, the Coros Pace 2 offers excellent features that cover a bit more than the basics of an Ironman Triathlon.

How to Choose the Best Triathlon Watch for Ironman

“Swim 2.4 miles! Bike 112 miles! Run 26.2 miles! Brag for the rest of your life.”

From its motto alone, it’s easy to see that the Ironman Triathlon was not made for the weak. It’s one of the greatest physical tests – and of the thousands that participate, only a few make it to the end.

The conditioning and training necessary to even compete in an Ironman are next-level. If you’re an aspiring or professional Ironman, you need all the help you can get, and investing in the right triathlon watch will give you a leg up in your training.

When thinking of buying the best Ironman Triathlon watch for your training, there are three things you need to consider: performance and metrics, build quality and battery life.

Performance and metrics dictate how in-depth you’re going to be in your monitoring and training. Typically, a few sports modes (especially the triathlon) are all you need, and maybe an analytics feature or two.

That said, if you’re gunning for the best possible time, you need to get right down to crunching numbers, so you’ll need a watch that offers professional monitoring and top-notch analytics, such as the ones provided by Garmin and Polar.

Since the Ironman is a brutal event, you need a watch that can measure up to the physical demands of the race. Durability and waterproofing is the primary concern here – you don’t want a watch that will break down in the middle of your training.

You also don’t want something that you can’t use during the swimming part of the competition. Luckily, all the watches on this list are strong enough to handle anything you put them through.

Lastly, go for as much battery power as you can. More than the competitions, the months leading up to the Ironman Triathlon will consist of rigorous training and physical conditioning. A drained watch should never be what holds you back in achieving your full potential.

Frequently Asked Questions

Which Ironman Triathlon watch is the best?

Speaking purely in terms of sports and performance features, it’s hard to beat Garmin’s offerings. Other models have come close, but so far, none could match the sheer scope and quality that premium Garmin sports watches like the Garmin Forerunner 945, Forerunner 745, and Fenix 6 Pro Titanium bring to the table.

Which Ironman Triathlon watch is most accurate?

Every brand and model featured in this list have incredible accuracy when it comes to their sensors. However, if you’re after industry-leading levels of sensor accuracy, go for premium Garmin watches such as the Garmin Fenix 6 Pro Titanium.

What’s the best watch brand for men?

All watch brands featured here (Coros, Garmin, Suunto, and Polar) are all recognized brands with well-loved selections of different triathlon-oriented watches. They all have different strengths and weaknesses, so the best watch brand for you will ultimately depend on your specific needs and preferences.

Conclusion

An Ironman Triathlon competition is one of the most physically demanding events you can join. Simply competing will require you to have above-average strength, speed, and stamina – not to mention the additional conditioning you’ll have to undertake to stand a chance of finishing.

As an aspiring Ironman, you’ll need all the help you can get, and you can find most of that in the right sports watch. With the best watch on your wrist, we’ve got no doubts that you’ll make it to the finish line.

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