Whether you're going for a big run in the park on your lunch break or you've decided to sign up for an Iron Man, triathlons require lots of intense training that will push your body to the limit. If you thought marathon training was hard, this is a whole new level of putting your body through agony.
Thankfully, you don't have to put in the laps and miles completely alone. There's plenty of wearable tech to give you a helping hand during those early morning or lunchtime sessions.
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From GPS watches to body suits, we've sifted through the best and worst of the kit to help turn you into a speedy swim-bike-runner.
Here's our top triathlon tech picks to help you be, ahem, tri-umphant.
Garmin Forerunner 935
The Garmin Forerunner 935 is a device built for triathletes and serious trainers - a successor to the Forerunner 735XT and a potential upgrade for those with a Forerunner 920XT strapped to their wrist.
Not only do you get the same sports tracking modes, built-in heart rate monitoring and a plethora of metrics to optimise training and aid recovery, it also offers Connect IQ support, notification support and plenty of battery life to help you go the distance.
Wareable verdict: Garmin Forerunner 935 review
Essentially, the 935 manages to pack many of the Garmin Fenix 5 features into a slimmer package.
Suunto Spartan Wrist HR
Suunto's latest multi-sport watch shares many of its qualities with the Suunto Spartan Sport, except one that's crucial for triathlete training - a heart rate sensor.
Wareable verdict: Suunto Spartan Sport Wrist HR review
This makes tracking multiple sports an even more in-depth experience, with 80 available for you to choose from in total. This list includes the likes of running, trail running, treadmill running, cycling and swimming (open and pool), but there's also a dedicated triathlon option for your perusal.
TomTom Spark 3 Cardio + Music
TomTom's updated multi-sport watch retains the built-in music player and still packs QuickGPSFix tech, meaning your location is picked up faster and maintained precisely; a must for keeping a track of your progress.
Wareable verdict: TomTom Spark 3 review
Real time information, whether you're running, cycling or swimming is displayed on-screen, while the design also won't weigh your wrist down. You won't supply with you the same detailed metrics as a Garmin, but it's a decent choice for someone who's venturing into the triathlon training world.
And there's a few options within the Spark 3 range to choose from, with the top of the line giving you access to heart rate monitoring, as well as music storage.
Garmin Forerunner 735XT
As you may already know, Garmin's XT range is built for those looking for a serious training companion – these are the multi-sport specific devices. Since the release of the bulky 920XT way back when, the company has also worked to reduce the size and bring the us the successor, the 735XT.
Wareable verdict: Garmin Forerunner 735XT
Despite being small enough to wear day-to-day, the watch crams in a powerful battery, optical heart-rate monitoring, all-day activity tracking, smartphone notifications and plenty of training metrics.
The V800's headline feature is its fantastic coaching system, which is ideal if you're just starting out your triathlon preparation. With the Polar Flow service, you can create tailored profiles for each sport, balance your training and recovery plus analyse even the most minute details.
Wareable verdict: Polar V800 review
Integrated GPS accurately tracks your runs, while pairing it with a heart rate monitor strap means it works when you've hit the pool.
Garmin Vivoactive HR
Much like the TomTom Spark 3, the Vivoactive HR could be a a good introduction to someone that's starting to think about venturing into the world of triathlons and wants to track more than one sport.
Wareable verdict: Garmin Vivoactive HR review
There's an optical heart rate monitor on board and GPS with dedicated apps included for cycling, swimming, running and a whole lot more. It also supports Garmin's Connect IQ apps so you can additional data fields and features. With solid battery life, it's definitely one to consider.
While we still put the Suunto Spartan Ultra and Spartan Wrist HR through their paces, the Ambit3 is still a great watch for you triathletes. It beams all the data it captures from multi-sports directly to a fantastic iPhone companion app all in one log.
There's a compass, speed, pace and distance tracking and it'll give you an activity based recovery time so you can tell when you should take a rest day. The heart rate monitor can also be used when you're swimming, while the tailored training programmes are great to keep you on track.
VRX MP3 + Personal Trainer
This duo of products gives you an underwater MP3, Real Coach training tips that will talk you through your swim as you're putting in the laps. You can even build custom workout plans to mix training sessions up.
Best of all, there's a silicone swim case that'll keep everything protected underwater so you can take them for a swim.
SKINS TRI400 Compression Tri Suit
The Skins Dynamic Gradient Compression delivers oxygen faster to your muscles, giving you more power. Recovery time is improved too, as lactic-acid build up is reduced.
The Toray fabric minimises drag, ideal for both the water and road, while integrated UV protection and moisture management make this the perfect fit for hot, sunny days.
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