Polar M430 Review: The GPS Watch That Can Improve Your Running

What the M430 lacks in style it makes up for in substance

Polar M430 GPS running watch on wrist
(Image: © Polar)

Our Verdict

Polar’s update of the popular M400 tracker is never going to win any awards for style, but it’s got bags of substance, with intelligent coaching features that link to the excellent Polar Flow training platform. Beginner runners in particular will benefit from the customisable guided workouts and training plans that you can follow on the M430, which puts heart rate at the centre of your sessions to ensure you’re working at the right intensity.


  • Quick to locate a GPS signal
  • Customisable screens
  • Back to Start feature guides you home during run or cycle
  • Easy and intuitive to use


  • At times uncomfortable design
  • Battery life is solid not spectacular

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Recent updates

This review was published August 15, 2017. It was updated in 2022 to improve the formatting after migration. Although still available, the M430 has been surpassed by newer models, including those which cost less. Browse our up-to-date lists of the best Polar watches and the best sports watches

Using The Polar M430 For Step Counting

While the M430 doesn't give you a dedicated step target to hit each day, it will record the number of steps you take and count them all towards your activity goal. As this is a GPS device primarily aimed at runners it’s not surprising that steps don’t take centre stage, but they are monitored and if you check out your daily activity report on either the device or the app, you can see your step tally.

Using The Polar M430 As A Heart Rate Monitor

The addition of optical heart rate tracking on the M430 is one of the major upgrades on the M400, which required users to wear a chest strap while exercising to gather that information. Polar has a reputation for making accurate heart rate monitoring straps around, so I had high expectations of the optical tracking in the M430.

After a few early issues, those expectations were met. In the first week or so of running with the M430 the heart rate would jump around a bit, and occasionally refuse to rise above a certain point no matter how hard I pushed myself. But following a software update these issues have not reared their heads again, and the heart rate readings on the M430 have been consistent with both a chest strap and the top-end Garmin Forerunner 935 GPS watch.

This is vital, because the M430 has gone all-in on heart rate. All the training sessions you can follow through Polar Flow are based on working in different heart rate zones, which is a great way to ensure everyone works at the same intensity no matter how experienced a runner they are.

It’s easy to keep tabs on your heart rate with dedicated screens showing which zone you are in at that moment and the overall period spent in each zone. While you’re being guided through a workout, another screen will indicate what your heart rate should be and buzz if it’s not in the right place.

You can also lock your heart rate into a certain zone mid-run by holding down the stop/start button for three seconds, prompting the M430 to buzz if you move out of this zone. I found this feature especially useful on long runs where I was meant to be taking it easy but found my effort level drifting up. The M430 would let me know when to ease off the gas.

Once a session is completed, the M430 will tell you how it benefited your training, largely based on heart rate. So a tempo session in higher heart rate zones will help you build speed, while a long run in lower zones helps build endurance. You also get a graph of your heart rate mapped on to the zones, which are colour-coded in the app (the screen of the M430 itself is black and white).

I’m a keen runner but I’d never really based sessions around my heart rate before using the M430, using pace to guide my training instead. After trying it, I’d say it is definitely something runners should consider to ensure they are working at the right effort in each session. The M430 makes using your heart rate to guide your training very clear and easy, especially if you use a Polar Flow training plan.

Currently the M430 tracks your heart rate only while you’re active, but in the third quarter of 2017 an update should bring all-day monitoring to the device, which will give more detail on your resting heart rate and, therefore, general fitness.

RECOMMENDED: Best Heart Rate Monitors

Using The Polar M430 To Track Activity

All of your daily activity is logged towards your My Day target on the M430. This target can be set to one of three levels, with level one being the least active and level three the most. How much activity you need to undertake to hit your goal depends on the intensity of the activity. For example, hitting level one requires 11hr 19min of low-intensity activity like standing at work, 2hr 12min of medium-intensity activity like walking, or 58min of high-intensity activity like running, or, more likely, a combination of all three.

The My Day screen shows steps, calories burned and your overall active time, as well as indicating what you’d need to do to hit your daily target. For example, right now I would need to do 1hr 30min of jogging to hit my goal in one go (I have it set to the the ambitious level three target and have done… nothing. Yet).

All the sports you track go towards your My Day goal, and the M430 can be used to track pretty much anything – simply add your favourite activity to the device via the Polar Flow app. You also get a full breakdown of your day’s activity via the app in the form of a circle which highlights periods where you were active (and how intense the activity was) and any long stretches when you sat in place.

The My Day feature is a more useful goal than a basic step target because it includes all your activities, but I found I rarely paid it much attention. If you’re looking for everyday tracking, it’s done more engagingly on devices like the Fitbit Charge 2 (which is also stylish enough to wear all the time), whereas the M430’s strength is in proper sports tracking.

Using The Polar M430 For Running

The M430 tracks many different kinds of activity very competently, but running is its main focus and where it excels. Even if you don’t use one of the training programmes – more on which later – the tracking is accurate and comprehensive, with enough data to satisfy even advanced runners.

Along with all the key stats like time, distance, pace, calories burned and heart rate, the M430 provides your cadence, an estimation of how demanding the run was which links to an overall training load to ensure you’re not overdoing it, and your running index. This last stat tells you how efficient your running is and it’s charted over time on the app. It uses this index to give an (in my experience, optimistic) estimation of how quickly you can complete a 5K, 10K, half and full marathon.

Speaking of those distances, you can get yourself into the best possible shape for a race by syncing one of the Polar Flow training programmes with the M430, a process that is mercifully simple. Using the Polar Flow website you set up your plan based on the event you’re doing and you’re current fitness level (it takes 20 seconds, max). The plan is then formed and synced to the Polar Flow app and M430. No wires required.

From there you can see the sessions you have coming up on the M430 and load up today’s workout at the click of a button. Each training plan has a mix of runs of different lengths and intensities, with each session guided by your heart rate. So you could do a phased run with five minutes in zones 1 and 2, five minutes in zone 3, then five minutes in zones 4 and 5, or an intervals session where you spike into the higher zones before resting.

Each session is guided by the M430 which breaks down the benefits of the training afterwards. The plans also include some basic strength and mobility training, which many runners unwisely skip.

The plans are excellent, especially for beginner runners unsure of how to prep for an event. The training programme will also adapt if you miss sessions, so you don’t have to bin it at the first failure. All in all, it’s brilliantly executed and if you follow the plans closely, there’s little doubt you will become a better runner.

However, if you are already an advanced runner with your own ideas about your training, you might find the plan gets a bit repetitive and end up skipping sessions to do your own thing.

There is also a lack of choice in the plans you can pick – there aren’t third-party plans to download as on Garmin Connect. That said, you can create your own sessions very easily on the Polar Flow website and sync them to the M430 to guide you through them. It’s more of a hassle than simply following the Polar plans, but for keen runners it allows close control over your training.

Finally, the M430 is very quick to lock on to GPS, faster than any of the Garmin or TomTom devices I’ve used.

Using The Polar M430 For Cycling

While the M430 takes a proactive approach to running, with coaching and training advice, it merely records your rides. You’ll get the usual stats – time, distance, heart rate, calories burned and average speed – plus pace zones, if you’d like to see how much time you spent going at certain speeds.

As with running, you’ll also be given a measure of how demanding your training was, which will add to your overall load to help ensure you’re not straining yourself too much. The M430 tracks cycling reliably, but has no specific metrics like power or cadence, so keen riders will be better served by a dedicated tracker or bike computer.

Polar M430 worn on wrist of someone tying shoelaces

(Image credit: Polar)

Using The Polar M430 For Swimming

The M430 is waterproof and will make an attempt to track your heart rate when swimming, although the results aren’t likely to be as accurate as when you’re undertaking dry activities. It also lacks specific metrics like SWOLF or even distance tracking, so if swimming is your main sport or you’re a dedicated triathlete you’ll probably want to look elsewhere.

RECOMMENDED: Best Swimming Watches

Using The Polar M430 For Calorie Counting

All individual activities you track with the M430 will produce a calories burned stat, and if you wear it all the time you’ll also get your total daily calorie count. Your training calendar on the Polar Flow app will also give you your total calories burned tally for each week. The data is all there, but as with most everyday tracking metrics, it’s not the real focus of the M430.

Using The Polar M430 As A Sleep Tracker

Sleep tracking is an area where Polar has developed its offering, and the M430 records your night’s rest in detail. You get a breakdown of how much time you spent asleep and interruptions, giving an overall rating for sleep continuity.

The M430, however, doesn’t divide up your snooze into deep and light sleep, and the device isn’t that comfortable to wear in bed. I wore the M430 for a few nights and found it slightly too bulky to completely ignore when trying to sleep, while the rubber strap does make the skin underneath hot even if you loosen it, which in turn makes the main unit flap around.

Polar has made a decent effort to make its sleep recording tech more insightful, but the M430 doesn’t feel like a device that can make the most of it.

RECOMMENDED: Best Sleep Trackers

The Polar Flow Website And App

Polar has achieved that rarest of feats with the Polar Flow website and app, in that data and training plans sync easily across both as well as the M430, so you can make changes to preferences and review your activities on each of them easily. TomTom and to a lesser extent Garmin should take note – if Polar can do all of this wirelessly, they can too.

Training programmes have to be set up on the website, and that’s where it’s easiest to review your in-depth running data, but you can also get by with the app and M430 easily for day to day training. The Polar Flow app also syncs to other third-party apps quickly so you can get your data on Strava.

Polar M430 Battery Life

The M430 has three options for accuracy when recording GPS activities, with the highest-accuracy option taking a GPS reading every second. You’ll get eight hours of juice in high-accuracy mode. In medium accuracy GPS is plotted every 30 seconds, and in low power mode it’s every 60 seconds. Opting for the power-saving mode will see the M430 last 30 hours while recording, but a GPS reading every 60 seconds won’t provide the accuracy needed for reliable run tracking.

I found that the Polar would just about last a week with four or five runs, but if I also cycled to work with it I’d have to make sure I charged it during the week. The M430’s battery life is solid enough that it isn’t annoying for recording your sports, although if you were wearing it all the time as an everyday tracker as well you’d probably have to charge it a couple of times a week.


The Polar’s design is very sporty and silicone-y, especially if you opt for the alarmingly orange colour. It’s also quite bulky and I found it would make the skin underneath it quite hot when worn for long periods. As a result, it belongs in the “only to be worn when active” camp, despite its everyday tracking features.

It’s primarily a GPS running watch, so this isn’t a major concern when it comes to ignoring your daily step count, but it’s a bit of shame it’s not more comfortable to wear while sleeping because its sleep tracking insights are solid.

Is The Polar M430 Worth It?

Polar has since released the Vantage M and Vantage V watches to update the M430 and V800 wearables respectively. The Vantage M is a lot more stylish than the M430 and offers advanced training analysis that tells you if, for example, you’re overtraining. However, it’s also £249 to the M430’s current price of £174.50, so it’s tempting to stick with the latter if you don’t mind the clunky design.

The M430’s competition from without, to become one of the best fitness trackers, comes mainly from Garmin, the big name in GPS running watches. The Forerunner 235 is usually available for a similar price and offers a similar package to runners as the M430.

There’s also the Garmin Forerunner 35, which is a terrific budget running watch usually available for £120 or so. The Polar M430 is more advanced than the Forerunner 35 and its training plans are a major plus compared to the Forerunner 35 or 235, so if following those plans is key for you then Polar will probably be the best way to go.

If you’re not so set on having all the running smarts contained in the Polar M430, you could also look at a more stylish everyday tracker like the Fitbit Versa or Fitbit Charge 3. Although neither has built-in GPS, they do offer GPS by connecting to your smartphone instead.

Nick Harris-Fry
Senior writer

Nick Harris-Fry is a journalist who has been covering health and fitness since 2015. Nick is an avid runner, covering 70-110km a week, which gives him ample opportunity to test a wide range of running shoes and running gear. He is also the chief tester for fitness trackers and running watches, treadmills and exercise bikes, and workout headphones.