Garmin Forerunner 735XT Review

Garmin Forerunner 735XT

At a Glance: Quick Ratings

Heart Rate Functions


Fitness / Sport Features


Ease of Use


Battery Life


Where To Get It

A Deep Dive Into The Garmin Forerunner 735XT 

The biggest innovation at Garmin in the last 24 months has been the Garmin Elevate HR sensor.

Using powerful LED sensors on the back of the watch heart rate is acquired directly off the wrist, without the need for a chest strap sensor.

Garmin’s large community of users in the multisport environment have been asking for this innovation to make it’s way in to a triathlon focused watch.

And that’s what this new Garmin Forerunner 735XT has gone and done. This review of the Forerunner 735XT has been prepared by Tristan Haskins aka CardioCritic

  • Who Is It For?

  • Video Review

  • Pros

  • Cons

The Garmin Forerunner 735XT is for the serious athlete who runs, bikes, swims and wants to be able to record a single training session/race with multiple sports changes in one session.

They want the convenience of heart rate without the need of a chest strap and they will appreciate the daily activity tracking and sleep monitoring offered by this watch.

They will be of a competitive nature and may, if they wish to, make use of the advanced training metrics like VO2 Max, Running Dynamics and Recovery Prediction.

If you are more inclined to RUNNING rather than multisport with cycling as your second sport, then you may well be satisfied with the Forerunner 235 with RUN & BIKE mode (but NOT the ability to change sports mode mid session)

The Perfect watch for Triathlon
The Forerunner 735XT adds multisport functionality to the brilliant Garmin Forerunner 235.

The 235 is still a favourite of mine for those that mainly RUN, but if you are a genuine “multisporter” and you want a sports watch that can switch between SWIM > BIKE > RUN modes at the press of a button then you need a dedicated triathlon watch, like this new Forerunner 735XT

Which Forerunner for you?
Confused by all the Forerunner watches? Don’t be. The Garmin Forerunner range of GPS sports watches is extensive with over a dozen models in the last 10 years. I’ve produced a short history of the Garmin Forerunner to help you get the latest and most appropriate Forerunner watch for your needs and budget.

Headline Feature – Off the Wrist Heart Rate

The Forerunner 735XT uses the Garmin Elevate OFF the WRIST heart rate sensors, so no need for a chest belt.

From our experience with the Forerunner 235 and the Vivosmart HR we are generally happy with the performance of this strapless heart rate monitoring system, but it’ still not PERFECT …

From our tests with these products we give them a rather unscientifically supported 95% accuracy for about 95% of the time. 

They seem to work BETTER when running / cardio / gym than they do on the bike (but maybe that’s because the roads in Norfolk are potholed).

When riding on smooth roads, then we did see a much get a better level of accuracy & consistency … If you are interested, we recently performed a test of Vivosmart HR versus Garmin Edge with CHEST strap sensor.

Top Features

  • Lightweight GPS multisport watch for tracking training data for running, cycling, swimming, multisport, hiking, skiing, strength, paddle sports and cardio
  • Tracks heart rate at the wrist day or night, to provide more accurate calories burned information
  • Access to Garmin Connect IQ APPS, widgets, watch faces and data fields.
  • Add Strava SUFFER score to your live
  • Provides an estimate of VO2 max, lactate threshold*, race predictor and recovery advisor
  • Running Dynamics provide information on stride length, ground contact time, balance, vertical ratio, power phase, platform centre offset and more
  • Swimming features: swim workouts, drill logging, rest timer, swim distance, stroke type/count and pool lengths
  • Smart Notifications: receive texts, emails, calls, and social media alerts on your watch
  • Activity tracking measures steps, sleep and calories burned all day. Water resistant (50m)
  • Completely connected with the full range of Garmin Varia cycling awareness products
  • Extended battery life of approximately 14 hours in GPS and HR mode
  • Watch the Videos

**lactate threshold required the use of an HRM chest sensor

Made for Multisport & Triathlon

For a watch to be classified by us as TRUE multisport watch it must meet a few criteria

It must have dedicated sports profiles for BIKE, RUN and SWIM with their own user configurable data fields.

It must be possible to move between sports in the SAME training session without having to STOP the watch and start a new session.

The Forerunner 735XT ticks both these boxes. It features built-in activity profiles for running (indoor/outdoor), cycling (indoor/outdoor), swimming (pool/open water), cross-country skiing, paddle sports, trail running, hiking and strength training.

For brick workouts and duathlon/triathlon races, the auto multisport feature allows the user to switch from one sport to another at the press of a button.

And for those who like to plan their training in advance, the FR735XT integrates with Garmin’s advanced workouts for running, cycling and pool swimming (new to this product). 

It’s simple to create your own personalized workouts then download them from Garmin Connect in to your Forerunner 735XT.

Power Meter Compatible – ANT+ only
For those who want to work with a power meter fitted on their bike, the Forerunner 735T is compatible with any ANT+ power meter. Naturally, Garmin want you to use their Vector pedals but there are various others on the market supporting ANT+ like the Stages Power cranks

24/7 Daily Activity Tracker

The Forerunner 735XT also happens to be a very proficient activity tracker.

With a daily target of steps you are motivated throughout the day to keep moving and get the blood pumping .. even if just taking a walk to the coffee machine.

The 735XT will track steps, distance and even the duration and quality of your sleep.

VO2 Max Predictor

Knowing your VO2 Max score if a great way of tracking your improving fitness. Each time you run/ride with the Forerunner 735XT it presents you with an estimated VO2 Max score.

This score is logged and can be viewed in the Garmin Connect APP to check progression / improvement.

Your VO2 Max is a measure of the millilitres of oxygen per your body weight (kg) per minute that you can move or utilise.

It’s a complicated and scientific metric to have professionally calculated but the FR735XT provides a consistent and reasonably accurate estimate. It is NOT necessary to use a chest strap HR sensor to get the VO2 Max score.

Race Predictor & Recovery Timer
Similarly, the Forerunner 735XT will also present you with a RACE TIME predictor, estimating your best performance at most common distance from 1 mile, through 5K, 10K, 10M, 1/2 marathon and full marathon.

From my tests with the Forerunner 235, these predictions were very accurate and reflected what I knew to be my PB times. So far it’s given us our VO2 Max and a prediction of our best race times… it’s now going to ensure you are fully recovered between sessions.

After each training session the Forerunner 735XT clearly shows you HOW LONG it will be until you are fully recovered from your hard work.

I found this Recovery Timer very useful and also in line with general advice. After a 1/2 marathon (using the FR235) the watch told me to recover for 50 hours… this may sound a lot, but that’s good advice. 2 -3 days of NOTHING following a half marathon is sensible advice.

Garmin Connect IQ APPS & widgets

As with the Garmin Forerunner 235 you can adapt your Forerunner 735XT to suit your daily needs. With an increasing number of Garmin Connect IQ apps, widgets, data fields and clock faces you are certain to get the watch that meets your needs.

The image below shows a Forerunner 735XT running an AccuWeather weather forecasting APP. Naturally, for these to work your watch must be in Bluetooth range of your connected smartphone. Some of these APPS are a bit of a gimmick, but most are very useful.

Strava Suffer Score ! (Connect IQ App)

Smartphone Connected

Smart notifications (reqs Android or iPhone connected) with automatic uploads of your training sessions to Garmin Connect.

It’s seamless features like these that make the Forerunner 735XT such an attractive proposition for busy athletes. 

When you’re on a long ride you can keep your phone tucked safely away in your back pocket and receive all your notifications on the watch.

It’s up to you which type of communication you see when out running and riding. You can ignore or respond to these notifications as you see fit.

Is it a 920XT with Built-In Heart Rate?

No. It’s not. There are some new features that you won’t find in the 920XT like the Strava Suffer Score and support of the Garmin Varia Vision system (rear facing radar system for rider safety)

The Forerunner 735XT is more similar in overall functionality to the Forerunner 235 with added multisport support. Garmin’s own website lists these as the main differences between the FR920XT and this new FR735XT model – however, it’s a little vague…

The Forerunner 735XT adds the following smartphone connected features:

  • Music Control
  • Find My Phone

However, it looses the Barometric Pressure sensor found in the 920XT along with the option to configure multiple bike profiles and the Virtual Pacer feature (comparing your current pace to a target pace). Also,with regard to NAVIGATION… the Forerunner 735XT does NOT allow you to store/follow routes or mark down GPS waypoints / locations to memory.

Battery Life

But it loses out on BATTERY LIFE to the 920XT. The Forerunner 735XT has a commendable expected battery life of 14 hours with both GPS and optical heart rate activated and, with UltraTac GPS saver turned on, you can expect as much as 24 hours (without optical HR).

 Compare this to the whopping 40 hours that the Forerunner 920XT gives you in UltraTac mode. What this means in the real world is if your expected IronMan finish time is over 12-13 hours, you might want to consider the 920XT – OR, you could use this 735XT with a chest strap heart rate monitor… We’ll know more when we get it a long term test complete.

From Garmin’s BLOG…..

We’re excited to today announce the Forerunner 735XT, a GPS running watch with multisport features and wrist-based heart rate. The most lightweight multisport-capable running watch from Garmin, the Forerunner 735XT features 24/7 heart rate monitoring and built-in activities including running, cycling, swimming, multisport, hiking, XC skiing, strength training, paddle sports and cardio. Its sleek design features soft, comfortable silicone bands with a large display so users can view stats at a glance during their workouts. Connect IQ compatible, the Forerunner 735XT is the first device to come with the Strava Live Suffer Score app pre-installed so users can track how hard they have been working based on heart rate data. Users can download additional free custom apps, watch faces, data fields and widgets from the Connect IQ™ store to further customize the Forerunner 735XT

Top Alternatives

Next Model UP

The only model superior to this Forerunner 735XT is the beautiful but bomb proof Garmin Fenix 3 HR.

Almost identical functionality with wrist based heart rate, GPS and barometric pressure sensor.

The Fenix 3 HR is the ultimate outdoor GPS sports watch for adventure racers and anyone who wants a watch that can stand up to pretty much anything.

Garmin fenix 3 HR Review – similar functionality incased in a more robust case – ideal for outdoor adventure racing.

Next Model DOWN

The model directly below this one is the Garmin Forerunner 235. Similar in style, looks and functionality the main difference is the lack of MULTISPORT support. The Forerunner 235 is primarily aimed at those who predominantly run.

Closest Competitor

The product from competitors with the closest functionality to this 735XT would be the Polar V800 and the Suunto Ambit3 Sport (or the Suunto Spartan Sport, new Oct 2021).

They all offer true multisport functionality with multiple disciplines being recorded in one exercise file. Each has it’s own pros and cons over the others and we would, in all honesty, be happy to use any for the duration of a triathlon and the training leading up to it.

However, none of these have WRIST BASED strapless heart rate monitoring.

Polar V800 Review – chest strap heart rate- excellent Triathlon / multisport watch
Suunto Ambit 3 Sport Review – a bit old now, I’d recommend the Spartan range
Suunto Spartan Sport Review – an excellent alternative to the Forerunner 735XT – Suunto’s best for years.

Looking for something else? Check out the 630 instead:

Review Summary

Could Garmin make the Forerunner 920XT any better? yes they can and they did with the Garmin Forerunner 735XT. There is no other review rating that I could give the 735XT other than 5/5 stars.

It’s technically superior to every other product on the market. The addition of the wrist based heart rate sensor is a huge convenience that gives it the edge of products like the Polar V800.

In summary, if you partake in triathlon or other multisport or ultra competitions it’s the obvious choice and comes very highly recommended.

Andrew Wyatt

Andrew Wyatt

Andrew Wyatt has been a tech geek for as long as he can remember. Whether it's laptops, cameras, or projects, he's obsessed with it all. When he's not researching the latest tech products, he likes to go on long hikes with his dogs.

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