Polar M430

The Polar M400 was Europe’s top-selling running watch in 2015-2016, so you won’t be surprised to hear that two years on, the upgrade – the Polar M430 – has retained almost everything that made the winning M400 such a hit.

And while from a distance it’s difficult to tell the M400 and the M430 apart, Polar has also added some extra hardware and features that mean this new running tool isn’t just the M400 with a new lick of paint.

The addition of optical heart rate, improved GPS and new sleep tracking skills make this a really strong entry on the sub-$230/£200/AU$330 shelf. In fact, if you’re looking for a mid-range tracker-cum-training tool that does the basics brilliantly with a simple, if retro, design then the M430 is it. 

If you want color touchscreens and a full suite of elite-level sports science metrics, you’ll probably want to jog on over to the aisle with the Garmin Forerunner 935 or the Polar V800.

The M430 is a capable piece of kit. Alongside all the basics your usual running watch serves up, such as pace, distance, speed and cadence, there’s optical heart rate from the wrist, full daily activity tracking, advanced sleep tracking, fitness tests and recovery time advice, all of which can be mined for insights once you’ve synced to the increasingly capable Polar Flow app or web tool.

There’s plenty here to satisfy a broad range of runners. From newcomers looking to run for general fitness, right up to people chasing a marathon personal best. There’s also just about enough for people pushing into short ultra territory, thanks to some battery-saving skills we’ll touch on later.

But what really makes the M430 stand out isn’t a load of shiny trickery, it’s that this watch combines simplicity with just the right amount of capability, at just the right price. 

The Polar M430 comes with a competitive price tag, as it can be picked up for £199.50 ($229.00, AU$329.00). That’s a good bit cheaper than the Garmin Forerunner 235 and a fair chunk less than the TomTom Adventurer too.

In our book that makes it one of the best running watches you can buy right now. But let us delve into more detail to explain why.

Design

• No frills, retro feel
• Comfortable, compact and light
• Uncomplicated, easy to use on the move

As we mentioned earlier, the M430 looks a lot like the M400 and despite coming in three colors: dark grey (what most people would consider black), white and go-faster orange, the truth is its appearance isn’t particularly exciting.

It looks like a sports GPS watch and if style is high up on your running watch priority list, there are definitely snazzier options out there - the Apple Watch 2, for example. This isn't a sleek running watch that doubles as a stylish timepiece for day-to-day life - it's clear you've got something fitness-led on your wrist.

The M430 retains the old school monochrome-style display that was on the M400. There’s no fancy color touchscreen here, but that’s no bad thing because the screen is clear and easy to read on the run in almost any light. 

As you’d expect you can also choose to invert the display and tap on a backlight so that it’s easier to read in darker conditions.

Probably the most significant design change is evident when you flip the M430 over to reveal the new 6 LED optical heart rate sensor, which is about the size of a 10 pence piece and protrudes a couple of millimetres.

Despite adding in the optical heart rate sensor, Polar has managed to shave a little off the weight from the M400, getting the the M430 down to 51g and 12mm thick. 

That’s just slightly heavier than the TomTom Adventurer at 55g but a good 10g weightier than the Garmin Forerunner 235.

The M400 wasn’t the most comfortable running watch in the world and Polar has tried to address this - with some success - on the M430 by adding a new softer silicone, breathable (that means it’s got holes in it) strap and a slightly more ergonomic design for a better fit on the wrist.

That’s good news because you have to wear this tighter to ensure the optical heart rate functions.

Overall, this is a relatively comfortable watch to wear. In our tests we used it on three ultra runs that lasted well over 10 hours without any complaints. Though like most optical heart rate watches, you do have to wear it tight enough to leave little indentations in the skin, and even in daily use the buckle will dig into the skin - there are more comfortable options out there.

The five button watch controls are the same as they were on the M400 and just as responsive. Each of them has quite a clear function and they’re extremely easy to use during runs.

It’s the little things that make all the difference and being able to long-press the top left button to access a quick menu of options, such as switching the backlight on, locking all the buttons (anyone who’s ever got to mile 23 of a marathon and realized their watch has stopped thanks to an accidental button tap will tell you how important this is) and sticking your watch in flight mode is a great touch.

From this menu you can also set up and start intervals really easily, even mid run. This includes sets of multiple intervals and the ability to mix up time and distance based intervals.

Another little tweak that might make some people jump for joy are the customizable watch faces. You can choose from five different layouts, none of them particularly exciting but this does provide you some degree of personalization.

Set up, sync and sharing

• Simple pairing and set up
• Smartphone sync sometimes fails

The M430 set up is easy and can be done via smartphone. You’ll need to download the Polar Flow app, pair your watch via Bluetooth just by tapping the device on your smartphone and you’re away.

If you want to get the most out of the watch it’s advisable to delve into the settings and set things like max heart rate, age, weight and height to ensure the data you get is tailored to you.

From the Polar Flow app you can also connect with third party apps to have all your data fired directly into Strava, Nike+, MyFitnessPal, Training Peaks and Facebook.

Post-run you can press and hold the back button to make the watch sync, provided your phone’s Bluetooth is activated. 

Although we found this to be temperamental and sometimes failed, meaning we had to hook up to a laptop using the USB cable or constantly try to re-pair the phone and smartwatch, like a digital marriage counsellor.

Once you’ve paired, you can also receive smart notifications from your phone on the watch screen, though text messages are clipped and all the while you’ve got this active you’ll be using up extra battery life on the device and your phone - so you’ll definitely want to switch this off for longer runs.

Optical heart rate and GPS tracking

• Reliable heart rate and GPS
• Heart rate accuracy drops in the water

Let’s start with the biggest upgrade on the M430, the addition of heart rate tracking from the wrist. 

Polar was quite slow to embrace optical heart rate but with the M430 it claims it's managed to improve the accuracy of this method of monitoring so that it can rival chest straps such as the Polar H10.

Despite the fact that Polar’s sensor has more LEDs than most other optical heart rate monitors, it’s not the number of LEDs that make the real difference. When it comes to accuracy and reliability, Polar is quite keen to point out that behind the extra LEDs, the M430 has far better heart rate algorithms to interpret the data than most watches.

Apparently this new software-hardware combination is far better at measuring rapid pulse changes, something that many wrist-based heart rate watches fail to do.

We tested the M430’s heart rate skills on a number of different runs, at different paces and up against the Suunto Spartan Sport HR, TomTom Adventurer and a chest strap and while there were some anomalies and spikes at the start of runs and when there was a significant change in pace or effort, in the main the M430 performed well.

As with a lot of heart rate trackers, it took a while to settle down at the start of runs but we didn’t see any crazy spikes once it had done so. It performed as well as any wrist-based heart rate device we’ve tested and overall was a pretty solid match for the chest strap.

Swim-bike-runners will be disappointed to hear that this sadly doesn’t carry into the pool. While the optical sensors do stay on in the water, the overall accuracy isn’t as good as what you get from dedicated swim monitors.

At the time of writing there was no 24/7 heart rate tracking so measuring your BPM when you’re not working out has to be done manually, but we’re told this update is coming toward the end of 2017.

Another area where Polar claims the M430 is better than its predecessor is GPS connectivity and accuracy. The M430 uses Assisted GPS (A-GPS) which basically tells your watch the latest predicted positions of the GPS satellites from your phone, making it quicker to acquire GPS when you want to run.

And it works well, particularly if you sync your watch regularly to get the latest A-GPS data. We tested the GPS link in a variety of different locations, urban, countryside and mountains and we never had to wait longer than 10 seconds to get a fix.

As you’d expect, the GPS gives you all the usual stats such as pace, speed and distance along with GPS-based altitude. On the run the GPS-based pacing was relatively responsive, though there were times where we felt a lag as the watch tried to catch up with a rapid increase in pace.

In terms of distance tracking, we tested the M430’s skills against four different marked and measured official race routes from 5km up to 120km mountain ultras and found it reliably hit kilometer markers and always came up slightly over the race distance as you’d expect.

We were promised better indoor run tracking too with a new accelerometer that more accurately tracks the movement of your wrist and converts that into distance, pace and speed. But we had mixed results.

For example, on one 6km run the overall distance on the watch tracked ahead of the treadmill and the pacing fluctuated by minutes per kilometer in front of our eyes. Considering the tracking works off arm movement that’s not surprising, but it does mean you can’t really look at the HR stats on the watch without it potentially affecting the accuracy.

That said, the overall distance on the treadmill and the watch once we’d completed the workout were 0.03km apart, with the watch logging a fraction extra.

Sleep tracking, activity tracking and fitness test

• Simple fitness test for easy benchmarking
• But the test often fails

A recent software upgrade has brought Sleep Plus intelligent sleep tracking to the Polar M430, a nod to the fact that sleep is increasingly being recognized as an important part of training and fitness. Too little quality rest can have a huge impact on your progress, harming recovery and making subsequent training sessions less effective.

This feature first appeared on Polar’s A370 fitness tracker and keeps tabs on a range of stats from the land of nod including sleep and wake times, total sleep duration, duration of sleep interruptions and when they occurred, sleep continuity (scored from 1-5) and overall quality of sleep.

You can also rate your own sleep the following morning via Polar Flow, do nightly comparisons and get some fairly rudimentary advice on how to improve your sleep.

All of the stats are gathered by tracking your position and wrist movements during sleep and are based on polysomnography, a reference measurement, which is the test used to assess sleep in science and medicine.

Let’s pretend for a second that we all agree sleep tracking is useful. Good. So how accurate and reliable is Polar’s version? Well, in our tests it definitely captured times when we woke during the night to use the toilet, or early in the morning for enough time to hit snooze.

It also always knew when we were and weren’t wearing the watch. The sleep start and end times were also spot on.

What was nice was the chance to give feedback in the morning, to tell the app how well you thought you'd slept. It helped shape the sleep analysis and really gave us some good data to play with when trying to improve our nightly slumber.

The Polar M430 also has a Fitness Test function that uses the watch’s built in heart rate monitor to do a quick assessment of your aerobic fitness levels anytime and anywhere, without the need for lab equipment and chest straps.

The test takes around 5 minutes and uses your resting heart rate, heart rate variability and your other personal info to estimate your VO2 Max – what Polar calls your OwnIndex.

The simple test basically involves lying down for 5 minutes while the watch does the hard work. However, the test failed a number of times for us, when the watch quite clearly struggled to maintain heart rate tracking for the full 5 minutes.

We repeatedly got a warning nudge that “the M430 should be worn snugly just behind the wrist bone”, even though that’s exactly how we were using it.

As for the results, well we got a VO2 Max read out of 67 which Polar said puts our fitness at the Elite level. It’s been a while since our last lab-based VO2 Max test but that came out at exactly 67, so it's probably being a touch generous (as many of these watch tests are).

The watch only displays your most recent Fitness Test results so you’ll have to fire up Polar Flow to track progress, but there’s a handy graph in the app that plots this nicely. The key thing is to use the VO2 Max changes, rather than the number, to work out fitness and the Polar M430 offers this option.

The M430 also brings the same general daily activity tracking that we saw in the Polar M400 complete with inactivity alerts, step count and active calorie burn. This is a pretty standard offering on most running watches and Polar’s is a good match for most.

Battery life

• Will easily last a marathon and beyond
• Option to extend battery with GPS accuracy settings
• Hate the fiddly proprietary charging cable

The M430 has a 240mAh battery which Polar claims offers 8 hours training time with GPS and optical heart rate in use and up to 20 days if you’re just using it to tell the time and track your general activity.

A great feature that’s been added here is the ability to change the settings to sacrifice some GPS accuracy to extend the battery life, this is particularly useful if you’re running into ultra territory where you don’t necessarily need your pacing with quite as much accuracy.

In terms of normal usage, let’s say a week with 2-3 runs of less than an hour plus a long run of around 2 hours, we found you’d probably need to charge the M430 once.

If you’re looking at continuous runtime with heart rate and the highest GPS accuracy level engaged, we got well over 8.5 hours and it was still going long after we’d stopped.

With the GPS accuracy set to low, we got over 14 hours of running though this did compromise the GPS accuracy quite significantly.

We’d love to see the same battery-saving logic applied to the heart rate sensor, but sadly that’s not yet possible.

One thing that’s definitely changed for the worse is the way you charge your M430. The Polar M400 could be stuck onto any standard micro USB cable that you’d use to charge an Android phone or a billion other devices in your home and at work.

But with the M430 Polar has introduced a custom-made USB port that requires a USB cable with a unique connector, meaning there’s only one cable that can charge your watch. 

Worse still, that special connector doesn’t clip in very firmly and on several occasions we came back to find it had fallen out and our watch was frustratingly uncharged.

Verdict

The Polar M430 is an accomplished running watch at a reasonable price, and if you've read this far into the review it should be well worth considering. But it's not for everyone, or the only option.

Who’s this for?

This is a great tool for anyone who considers themselves a goal-driven runner and while you don’t have to be chasing a personal best or training for a marathon to see the benefits, if at some stage you think that’s where you’ll end up, this is a device that’s capable of coping with developing running ambitions.

For those whose goals already include faster half and marathon times, shorter ultras or just fat-burn or general running fitness, the M430 has enough features to be a really useful training and racing aid.

Should you buy it?

If you’re one of the people who bought the best-selling M400 and you’re looking for a familiar upgrade that brings some new skills to your training, then the M430 should satisfy, though there will almost certainly be people who’d like to see more done with the design and screen.

For everyone else, this is a competent running watch with a rich feature set, some great all-day activity and sleep-tracking features and for under $230/£200/AU$330 won’t disappoint.

We're impressed by the Polar M430 but there are other fine fitness-focused wearables too, such as the following three.

Suunto Spartan Sport Wrist HR

The first Suunto with heart rate tracking from the wrist, the waterproof Spartan Sport Wrist HR is another pulse tracking multi-sport watch, but this one is built for runners who want a bit more adventure.

It’s a chunk pricier than the Polar M430, but then if you’re looking for a tool that’ll take you from tarmac to trail then the crisp, toughened color touchscreen, GPS route navigation, a compass and up to 16 hours battery in training mode, fit the bill.

Garmin Forerunner 235

The successor to the Garmin Forerunner 225, the Forerunner 235 carries much the same specs and features including built-in heart rate, 24/7 activity tracking, training plans and VO2 Max stats to provide similar fitness and recovery insights, but comes with a sleeker, more modern design.

There’s a color screen, smart notifications and syncing with Strava via Garmin Connect. Those with smaller wrists will also favor the fact that you can swap out the Forerunner 235’s bands for a better fit than the M430’s one-size-fits-all fixed bands.

TomTom Spark 3 Cardio + Music

TomTom’s latest wrist-based heart rate tracking tool also offers GPS tracking for multi sport and 24/7 activity tracking, but where it differs from the Polar M430 and the Forerunner 235 is the ability to store up to 500 songs locally on the watch, meaning you can whack on a pair of Bluetooth headphones and run phone-free.

The web tools aren’t anywhere near as advanced as Garmin Connect or Polar Flow, but this is a strong alternative if you love running with music but hate bringing your smartphone.

• Read our full TomTom Spark 3 review

First reviewed: August 2017
Gareth Beavis contributed to this review