Polar M430 Review

I rather like the M430, but I fear it's not enough of an improvement over the M400 to justify the extra cost, nor is it good enough for me to recommend it over the equivalent Garmin watches. The main a change from the M400 is the addition of an Optical Heart Rate Monitor, which would be a truly wonderful invention if it worked. Sadly, I don't see this replacing the traditional ECG-based heart rate monitor anytime soon, as much as I hate the inconvenience and chafing of the chest strap.

1 The Big Questions

I use four simple questions that I think cut to the heart of want most runners are looking for in a running watch. There's obviously a lot of nuance and detail that you can dig into, and I try to provide that as well, but hopefully these questions and their answers will give you an idea of whether or not it's worth reading further.

• How far did I run? This is the most basic question, and the M430 has middling GPS accuracy, but this can be offset by using the Stryd Footpod. The M430 can use the Stryd and record a GPS track, something that some of its competition can't manage. If you dig into the details of its GPS accuracy, you'll notice that it's distance errors are more likely to even out over greater distances than you might expect from its overall accuracy score.
• How fast am I running? Knowing how fast you're running can be a nice to know, or it can be vital for your training or race performance. Because of the nature of GPS, watches that rely on GPS signal alone tend to have serious problems with current pace. With the Stryd Footpod, you can get extremely accurate pace information. If you can't afford the Stryd Footpod, then you can use the MilestonePod which requires calibration, but is cheap and accurate. Without a Footpod, the M430's pace display is pretty hopeless.
• Where am I? The M430 has only a simple "back to start" arrow, which is better than nothing, but remember this is an "as the crow flies" direct path, not a backtrack.
• What's my cadence? Cadence is one of the most critical and often overlooked aspects of running. If you get your Cadence right, many other things naturally fall into place. The M430 has support for other Footpods besides Stryd, plus it has support for Cadence from the internal accelerometer. There are no Cadence alerts which is a shame, but typically this feature is only available on more expensive devices.

The M430 is not a good choice for ultrarunners, as its battery life is too short at just 8 hours. See Watches for Ultrarunning for more details.

Please support this site This review was made possible by readers like you buying products via my links. I buy all the products I review through normal retail channels, which allows me to create unbiased reviews free from the influence of reciprocity, or the need to keep vendors happy. It also ensures I don't get "reviewer specials" that are better than the retail versions.

2 Should You Buy The M430?

This is a tougher question than I'd like, but generally I think the answer is "no". Not because the M430 has any significant flaws, but because of the stiff competition in this price range.

• Buy the Garmin Vivoactive. The Vivoactive has far more functionality than the M430, including Connect IQ that allows for expanded functionality through downloaded apps. The Vivoactive is a vastly better activity tracker, especially when combined with a good Connect IQ watch face that gives you better feedback on how you're doing. The main limitation to the Vivoactive is that there's no Optical Heart Rate Monitor and it can't record the GPS track whilst getting pace and distance from a Stryd Footpod. If these are problems, read the next bullets.
• Buy the Garmin Vivoactive HR. Optical Heart Rate Monitors don't work well enough for real world usage, but if you want one anyway, then consider the Garmin Vivoactive HR. Like the non-OHRM Vivoactive above, it can't record the GPS track whilst getting pace and distance from a Stryd Footpod. If you really want the GPS track and accurate pace/distance, then look to the Polar M400.
• Buy the Polar M400. With the release of the M430, the Polar M400 has dropped in price, and I think in most cases I'd go for the previous generation, or the. The main change to the M430 from the M400 is the addition of it's Optical Heart Rate Monitor (OHRM), but like most similar systems, it doesn't work well enough for real world usage, so the M400 is a good option.
• Spend more. If you have a larger budget, I'd recommend taking a look at the Garmin Fenix 3, or check out the decision guide at Best Running Watches.

3 Polar M430 Pros

• The user interface is nicely designed and intuitive; the buttons, display, and the menu system combine aesthetics with usability. The M430 has five hard buttons, which I much prefer over a touchscreen interface, especially when wearing gloves or in the rain.
• The support for Stryd is pretty good. As noted above, you can get pace and distance information from the Stryd whilst still recording a GPS track. The limited navigation features mean that the GPS data doesn't provide much value while you're running, but it does allow you to see where you went afterwards. You can only get the Stryd estimate of power through the cadence field, and that feature might disappear in the future.
• The M430 also supports the MilestonePod, which is the best option if you can't afford the Stryd footpod.
• Polar, like Suunto, allow their watches to be configured via the website, which is easier than fiddling with the watch itself. Some of the options can be also set on the watch, which means you're not stuck if you're away from the Internet.
• The M430 provides more information when you press the lap button than most other watches, including average and max heart rate, etc.

4 Polar M430 Cons

• Unlike the Polar V800, the M430 has poor GPS Accuracy, though I think there may be scope for improvement. See below for more details.
• The M430 will auto-pair with Bluetooth sensors, which sounds useful until you find it trying to repeatedly pair with sensors nearby. The only way of disabling this that I could find is to put the M430 in airplane mode, which means it won't pick up the sensors you're using. Hopefully Polar will fix this soon.
• The M430 can only act as a simple activity monitor, with the only motivation display a simple progress bar. If you compare this with Garmin watches that support Connect IQ, which can provide things like a graph of the daily activity over the last week.
• Like the Polar V800, the M430 uses visual tricks to appear smaller than it is. The watch is curved, so the first part of the watch strap is really part of the watch body. This can cause problems for runners with smaller or larger wrists. I have to wear the V800 and M430 over a wrist sweat band as my writs are quite small. (I have no problem with watches that appear to be bigger, like the Garmin 310XT.)
• The M430 will give an estimate of V̇O₂max if you're wearing a Heart Rate Monitor, but I didn't find its estimate as accurate as the Firstbeat software used by Garmin and Suunto.
• It's a minor problem, but if you have a Heart Rate Monitor strap paired with the M430 but don't have it on you, the M430 will wildly overestimate your calories and effort.

5 Polar M430 Other Features

I try to put most items into either pros or cons, but there are some that depend on your perspective.

• The Optical Heart Rate Monitor (OHRM) works about as well as any other system, which means it's not much use in the real world.
• The battery on the M430 lasts the claimed 8 hours, which should be enough for the vast majority of marathon runners, but most ultramarathons would be too long and the M430 can't be charged on the run easily.

6 Differences Between M430 and M400

There are a few differences between the M430 and the M400 to consider.

• The M430 has better GPS accuracy than its predecessor. It generally believed that it uses the same chipset family as the Polar V800 (SiRFstarIV), though it doesn't have the same accuracy as the V800 (it may not be the same chipset, just the same family.)
• Polar added their Optical Heart Rate Monitor (OHRM) to the M430.
• Something as simple as the vibration alert is most welcome.
• You can now select a lower accuracy, intermittent polling mode for GPS which increases battery life up to 30 hours by only recording one sample per minute.
• There is now a rather limited selection of watch faces, but don't expect anything like the flexibility of a Garmin Connect IQ enabled watch.
• The use of a Micro USB connector of the M400 has been replaced with a nonstandard connector. Using a micro USB connector has the obvious appeal of using any cable, but it seems that this has caused too many problems in practice. (I found it worked fine for me, other than the typical USB problem of not knowing which way round to put in the cable.)

7 GPS Accuracy

The GPS Accuracy of the M430 is a fairly reasonable for a modern running watch, though you could argue that's "damned with faint praise." I believe that with the advent of the extremely accurate Stryd Footpod, GPS accuracy is rather less of an issue. However, for runners not wanting to spend so much on a Footpod, GPS accuracy may still be important. For a detailed comparison of the M430 with its competitors, check out my GPS Accuracy page. For those wanting something a little more qualitative rather than quantitative, the image below may help give a more intuitive look at the accuracy. You'll see that generally the tracks follow the path reasonably well, with only a tiny number wondering off on their own. The M430 does a pretty good job in the curvy sections of the path, an area that typically reveals weaknesses in the GPS accuracy. You'll notice that most tracks are a similar shade of green, showing a good degree of consistency, though not the highest level of accuracy. One peculiarity with the M430 is the way it records lap markers so far away from the actual location; there is no clustering of the lap markers at all, and it looks to me like a strange skin disease. I feel like this is a software bug rather than an intrinsic problem in of the hardware, and I'm hopeful that Polar may be able to improve their GPS accuracy in future firmware releases. (I tested with the 1.0.28 firmware.) If you look at the statistical analysis of this watch, your notice that it's trueness score is disproportionately high when compared to its precision score. This means that over longer distances this watches errors are more likely to even out than you might expect from it overall accuracy score. This does make me wonder if there's more room for improvements in software we might see in the future.

Here's the tracks from the M430. This diagram has tracks color coded with green indicating good accuracy through to red indicating poor accuracy, and the lap markers as blue dots

If you compare the image above with the image from the Polar V800 shown below, you can see the darker green lines indicating a more accurate recording.

The Polar V800 tracks.

Here's the tracks from the extremely accurate Suunto Ambit3, showing how the lap markers should look.

The Suunto Ambit3 tracks.

8 What's Missing

While I don't consider these missing features as 'cons', it's worth understanding the features that are missing compared with other watches.

• Altimeter. GPS is far less accurate vertically than horizontally, so a barometric altimeter can provide a much better idea of your ascent and descent. It can also be useful for navigation if you're ascending or descending a mountain. In some races I've been far more interested in how much ascent is left rather than the distance to the top.
• Navigation. The navigation capabilities are useful if there is a risk of getting lost. I've made good use of this feature when running in an unfamiliar city, or when running remote trails. There is a rudimentary "back to start" functionality that gives you an arrow pointing back, but that's a poor substitute.
• Downloadable Apps. Smart watches have got is used to the idea of a device that can be extended with new functionality, and this concept is being introduced to running watches.
• Training Effect. The Firstbeat Training Effect gives you a sense of how hard each workout is, and this sometimes includes the time for recovery.
• Graphs. Instead of simply displaying a numeric value for things like heart rate, some watches will display a graph of the value over time, giving you a sense of how things are progressing.
• Running Dynamics. Some of the newer Garmin watches can show and record Vertical Oscillation (VO) and Ground Contact Time (GCT).
• Alerts. Some watches will alert you when a metric is out of range. The alert for Cadence is really useful and one of my favorite features.

9 Comparison Table

I evaluate running watches in three distinct ways. Firstly, you can use a watch on its own, without any kind of Footpod. This is probably the most common way runners use their watch, but you miss out on a lot. The second rating is with a standard Footpod that is available quite cheaply. These Footpod's can be reasonably accurate once the calibrated, but calibration is a little tedious. The final evaluation is with the Stryd Footpod, which is vastly more accurate than any other type of Footpod, or and more accurate than GPS. The table below looks at the score, and the value for money of each watch for each of the three conditions. (I’ve also tested the Apple Watch 3, but I’ve not included it in these tables as it’s not really a running watch.)

Review	With Stryd Score	With Stryd Value for money	With Footpod Score	With Footpod Value for money	Without Footpod Score	Without Footpod Value for money	Price at Amazon.com
Garmin Epix Review	47	4.5	31	3.9	23	3.4
Garmin Fenix 5X Review	47	2.9	32	2.3	24	1.9
Garmin Fenix 3 Review	45	3.8	28	3.1	24	3
Garmin 935 Review	45	3.6	30	3	22	2.4
Garmin Vivoactive HR Review	40	4.9	21	3.8	17	3.8
Garmin 920XT Review	39	4.4	30	4.7	24	4.5
Suunto Spartan Ultra Review	37	2.6	27	2.3	23	2.1
Garmin Vivoactive 3 Review	36	4	19	2.9	15	2.8
Garmin Vivoactive Review	34	5.1	14	3.4	10	3.3
Suunto Spartan Trainer Review	34	3.9	23	3.7	18	3.4
Polar V800 Review	33	2.8	26	2.8	22	2.7
Suunto Ambit2 Review	32	3.9	25	4.3	21	4.5
Suunto Ambit3 Peak Review	32	3.4	29	4.1	25	4.2
Garmin Fenix 2 Review	31	2.9	22	2.7	18	2.5
Suunto Ambit3 Run Review	30	4	27	5.5	23	5.9
Suunto Ambit2 R Review	30	3.5	23	3.8	19	3.8
Garmin 235 Review	28	2.9	20	2.8	12	2
Garmin 620 Review	27	3.8	24	5.1	20	5.6
Garmin 910XT Review	26	3.9	26	6.1	21	6.7
Garmin 310XT Review	25	4.6	24	8.3	18	10
Polar M400 Review	25	4.3	15	4.5	11	4.9
Garmin 225 Review	25	3.8	13	3.1	9	2.9
TomTom Cardio Runner Review	25	3.3	10	2	10	2.5
Polar M430 Review	25	3.2	15	2.9	11	2.7
Garmin 610 Review	24	3.3	20	4.3	14	3.9
Leikr Review	10	1	20	2.5	14	2	Leikr ($380)
Epson SF-510 Review	4	0.7	6	2	6	3
Epson SF-810 Review	4	0.6	6	1.6	6	2.3
Garmin 10 Review	2	0.3	2	0.6	2	0.9

The score is the sum of how well each watch can answer the four basic questions (how far, how fast, where are you, what's your cadence), plus some bonus points.

1. The "How far you've run" will be based on GPS only for "without Footpod" and "with Standard Footpod", but based on Stryd if supported in the "with Stryd Footpod" table..
2. How fast you're running assumes you're using a Footpod if it's supported, otherwise the rating is 0-2 based on GPS accuracy.
3. The "Where are you?" is based on various navigation features such as back to start, breadcrumbs, and preloaded maps. For some watches, you have to turn GPS off to get the benefit of Stryd, so those watches have worse "where are you scores" with Stryd than without.
4. The cadence score uses 1 point for an internal cadence sensor, 2 points for footpod support, 1 point for support from chest strap cadence, and 1 point for cadence alerts.
5. I give 1-2 bonus points for application support, 1-2 bonus points for data upload, 1-2 bonus points for Optical Heart Rate Monitoring, and 0-1 bonus points for battery life.
6. Value for money is the score divided by the price (at the time I last updated the table.) Your needs may be different, so you might weight the different aspects of the watches differently, or be basing your decision on different criteria totally. Hopefully this table will give you a good starting point for your decision.

9.1 Score Breakdown without a Footpod

Review	Score	Value for money6	How far did you run?1	How fast are you running?2	Where are you?3	What's your cadence?4	Bonus Points5	class="unsortable" | Price at Amazon.com
Suunto Ambit3 Peak Review	25	4.2	8	3	6	2	6
Garmin 920XT Review	24	4.5	1	2	7	6	8
Garmin Fenix 3 Review	24	3	2	1	7	6	8
Garmin Fenix 5X Review	24	1.9	1	0	9	6	8
Suunto Ambit3 Run Review	23	5.9	8	3	5	2	5
Garmin Epix Review	23	3.4	0	0	9	6	8
Suunto Spartan Ultra Review	23	2.1	8	2	6	2	5
Polar V800 Review	22	2.7	9	4	3	2	4
Garmin 935 Review	22	2.4	1	0	7	6	8
Garmin 910XT Review	21	6.7	5	3	6	2	5
Suunto Ambit2 Review	21	4.5	4	3	6	2	6
Garmin 620 Review	20	5.6	3	2	2	6	7
Suunto Ambit2 R Review	19	3.8	4	3	5	2	5
Garmin 310XT Review	18	10	7	2	4	0	5
Suunto Spartan Trainer Review	18	3.4	5	3	4	2	4
Garmin Fenix 2 Review	18	2.5	1	0	6	6	5
Garmin Vivoactive HR Review	17	3.8	0	0	2	6	9
Garmin Vivoactive 3 Review	15	2.8	0	0	4	4	7
Garmin 610 Review	14	3.9	3	2	3	2	4
Leikr Review	14	2	5	2	4	0	3	Leikr ($380)
Garmin 235 Review	12	2	0	0	2	2	8
Polar M400 Review	11	4.9	3	1	1	2	4
Polar M430 Review	11	2.7	3	1	1	2	4
Garmin Vivoactive Review	10	3.3	0	0	0	6	4
TomTom Cardio Runner Review	10	2.5	2	1	0	2	5
Garmin 225 Review	9	2.9	1	1	0	2	5
Epson SF-510 Review	6	3	0	0	0	2	4
Epson SF-810 Review	6	2.3	1	0	0	2	3
Garmin 10 Review	2	0.9	0	0	0	0	2

9.2 Score Breakdown with a Standard Footpod

Review	Score	Value for money6	How far did you run?1	How fast are you running?2	Where are you?3	What's your cadence?4	Bonus Points5	class="unsortable" | Price at Amazon.com
Garmin Fenix 5X Review	32	2.3	1	4	9	10	8
Garmin Epix Review	31	3.9	0	4	9	10	8
Garmin 920XT Review	30	4.7	1	4	7	10	8
Garmin 935 Review	30	3	1	4	7	10	8
Suunto Ambit3 Peak Review	29	4.1	8	3	6	6	6
Garmin Fenix 3 Review	28	3.1	2	1	7	10	8
Suunto Ambit3 Run Review	27	5.5	8	3	5	6	5
Suunto Spartan Ultra Review	27	2.3	8	2	6	6	5
Garmin 910XT Review	26	6.1	5	4	6	6	5
Polar V800 Review	26	2.8	9	4	3	6	4
Suunto Ambit2 Review	25	4.3	4	3	6	6	6
Garmin 310XT Review	24	8.3	7	4	4	4	5
Garmin 620 Review	24	5.1	3	2	2	10	7
Suunto Ambit2 R Review	23	3.8	4	3	5	6	5
Suunto Spartan Trainer Review	23	3.7	5	4	4	6	4
Garmin Fenix 2 Review	22	2.7	1	0	6	10	5
Garmin Vivoactive HR Review	21	3.8	0	0	2	10	9
Garmin 610 Review	20	4.3	3	4	3	6	4
Garmin 235 Review	20	2.8	0	4	2	6	8
Leikr Review	20	2.5	5	4	4	4	3	Leikr ($380)
Garmin Vivoactive 3 Review	19	2.9	0	0	4	8	7
Polar M400 Review	15	4.5	3	1	1	6	4
Polar M430 Review	15	2.9	3	1	1	6	4
Garmin Vivoactive Review	14	3.4	0	0	0	10	4
Garmin 225 Review	13	3.1	1	1	0	6	5
TomTom Cardio Runner Review	10	2	2	1	0	2	5
Epson SF-510 Review	6	2	0	0	0	2	4
Epson SF-810 Review	6	1.6	1	0	0	2	3
Garmin 10 Review	2	0.6	0	0	0	0	2

9.3 Score Breakdown with a Stryd Footpod

Review	Score	Value for money6	How far did you run?1	How fast are you running?2	Where are you?3	What's your cadence?4	Bonus Points5	class="unsortable" | Price at Amazon.com
Garmin Epix Review	47	4.5	10	10	9	10	8
Garmin Fenix 5X Review	47	2.9	10	10	9	10	8
Garmin Fenix 3 Review	45	3.8	10	10	7	10	8
Garmin 935 Review	45	3.6	10	10	7	10	8
Garmin Vivoactive HR Review	40	4.9	10	10	1	10	9
Garmin 920XT Review	39	4.4	10	10	1	10	8
Suunto Spartan Ultra Review	37	2.6	10	10	6	6	5
Garmin Vivoactive 3 Review	36	4	10	10	1	8	7
Garmin Vivoactive Review	34	5.1	10	10	0	10	4
Suunto Spartan Trainer Review	34	3.9	10	10	4	6	4
Polar V800 Review	33	2.8	10	10	3	6	4
Suunto Ambit2 Review	32	3.9	10	10	6	0	6
Suunto Ambit3 Peak Review	32	3.4	10	10	6	0	6
Garmin Fenix 2 Review	31	2.9	10	10	6	0	5
Suunto Ambit3 Run Review	30	4	10	10	5	0	5
Suunto Ambit2 R Review	30	3.5	10	10	5	0	5
Garmin 235 Review	28	2.9	10	10	0	0	8
Garmin 620 Review	27	3.8	10	10	0	0	7
Garmin 910XT Review	26	3.9	10	10	1	0	5
Garmin 310XT Review	25	4.6	10	10	0	0	5
Polar M400 Review	25	4.3	10	10	1	0	4
Garmin 225 Review	25	3.8	10	10	0	0	5
TomTom Cardio Runner Review	25	3.3	10	10	0	0	5
Polar M430 Review	25	3.2	10	10	1	0	4
Garmin 610 Review	24	3.3	10	10	0	0	4
Leikr Review	10	1	5	2	0	0	3	Leikr ($380)
Epson SF-510 Review	4	0.7	0	0	0	0	4
Epson SF-810 Review	4	0.6	1	0	0	0	3
Garmin 10 Review	2	0.3	0	0	0	0	2

9.4 Basic Features

Review	Released	GPS Accuracy	Weight (oz)	Size (CM3)	Display (mm)	Resolution (Pixels)	Waterproofing	Heart Rate Monitor	Cadence	Data Upload
Garmin Epix Review	2015	6.2	3.0	48	29 x 21 (609mm2)	205 x 148 (30.3K total)	Good (50m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Garmin Fenix 5X Review	2017	5.6	3.5	36	30.5 (round) (731mm2)	240 diameter (45.2K total)	Good (100m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Garmin Fenix 3 Review	2015	6.2	2.9	33	30 (round) (726mm2)	218 diameter (37.3K total)	Good (100m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Garmin 935 Review	2017	5.6	1.7	24	30.5 (round) (731mm2)	240 diameter (45.2K total)	Good (100m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Garmin Vivoactive HR Review	2016	4.9	1.7	19	21 x 29 (609mm2)	148 x 205 (30.3K total)	Good (50m)	Yes (+OHRM)	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Garmin 920XT Review	2014	6.6	2.2	35	29 x 21 (609mm2)	205 x 148 (30.3K total)	Good (50m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Garmin Vivoactive 3 Review	2017		1.5	17	30.5 (round) (731mm2)	240 diameter (45.2K total)	Good (50m)	Yes (+OHRM)	Internal/Footpod	Yes
Garmin Vivoactive Review	2015	5.4	1.3	13	29 x 21 (592mm2)	205 x 148 (30.3K total)	Good (50m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Suunto Spartan Trainer Review	2017	7.8	2.0	25	24 x 23 (529mm2)	128 diameter (12.9K total)	Good (50m)	Yes (+OHRM)	Internal/Footpod	Yes
Suunto Ambit2 Review	2013	7.6	3.1	30	29 (round) (661mm2)	128 diameter (12.9K total)	Good (100m)	Yes	Internal/Footpod	Yes
Suunto Ambit3 Peak Review	2014	7.9	2.9	30	29 (round) (661mm2)	128 diameter (12.9K total)	Good (100m)	Yes	Internal/Footpod	Yes
Suunto Spartan Ultra Review	2016	7.1	2.7	38	32 (round) (804mm2)	320 diameter (80.4K total)	Good (100m)	Yes	Internal (Limited Footpod)	Yes
Garmin Fenix 2 Review	2014	5.7	3.2	32	31 (round) (755mm2)	70 diameter (3.8K total)	Good (50m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Suunto Ambit3 Run Review	2014	7.9	2.5	30	29 (round) (661mm2)	128 x 128 (16.4K total)	Good (50m)	Yes	Internal/Footpod	Yes
Suunto Ambit2 R Review	2013	7.6	2.5	30	29 (round) (661mm2)	128 diameter (12.9K total)	Good (50m)	Yes	Internal/Footpod	Yes
Garmin 235 Review	2015	4.9	1.5	19	31 (round) (755mm2)	215 diameter (36.3K total)	Good (50m)	Yes (+OHRM)	Internal/Footpod	Yes
Garmin 620 Review	2013	7.1	1.5	20	25.4 (round) (507mm2)	180 diameter (25.4K total)	Good (50m)	Yes	Internal/Footpod/Heart Rate Monitor/Alert	Yes
Garmin 910XT Review	2011	7.5	2.5	49	33 x 20 (660mm2)	160 x 100 (16K total)	Good (50m)	Yes	Footpod/Alert	Yes
Garmin 310XT Review	2009	7.5	2.5	63	33 x 20 (660mm2)	160 x 100 (16K total)	Good (50m)	Yes	Footpod	Yes
Garmin 225 Review	2015	6.2	1.5	24	25.4 (round) (507mm2)	180 diameter (25.4K total)	Good (50m)	Yes (+OHRM)	Internal/Footpod	Yes
TomTom Cardio Runner Review	2015	6.0	2.2	30	22 x 25 (550mm2)	144 x 168 (24.2K total)	Good (50m)	Yes (+OHRM)	Internal/Footpod	Yes
Polar V800 Review	2014	8.0	2.8	31	23 x 23 (529mm2)	128 x 128 (16.4K total)	Good (30m)	Yes	Internal/Footpod	Yes
Polar M430 Review	2017	7.2	2.0	24	23 x 23 (529mm2)	128 x 128 (16.4K total)	Good (50m)	Yes (+OHRM)	Internal/Footpod	Yes
Polar M400 Review	2014	6.6	2.0	24	23 x 23 (529mm2)	128 x 128 (16.4K total)	Good (30m)	Yes	Internal/Footpod	Yes
Garmin 610 Review	2011	7.3	2.5	41	25.4 (round) (507mm2)	128 diameter (12.9K total)	Fair (IPX7)	Yes	Footpod/Alert	Yes
Leikr Review	2013	7.3	2.4	25	41 x 31 (1271mm2)	206 x 148 (76.8K total)	Fair (IPX6)	Yes	Footpod	Limited
Epson SF-510 Review	2015	4.4	1.7	24	28 x 22 (616mm2)	128 x 96 (12.3K total)	Good (50m)	Yes	Limited Internal	Limited
Epson SF-810 Review	2015	5.5	1.8	28	28 (round) (616mm2)	128 diameter (12.9K total)	Good (50m)	OHRM Only)	Limited Internal	Limited
Garmin 10 Review	2012	3.8	1.3	33	25 x 24 (600mm2)	55 x 32 (1.8K total)	Good (50m)	No	No	Yes

Review	Battery Life (hr)	Tested Battery Life (hr)	Extended Battery Life (hr)	Charge On The Run?	Training Effect	HRV	GPS cache	Sensors
Garmin Epix Review	24	17.6	50	Yes (with USB=Garmin)	Yes	Record	Yes	Ant+
Garmin Fenix 5X Review	20	23	35	Yes, but can't be worn	Yes	Record	Yes	Bluetooth/Ant+
Garmin Fenix 3 Review	20	22	50	Yes (with USB=Garmin)	Yes	No	Yes	Ant+
Garmin 935 Review	24	24.5	60	Yes, but can't be worn	Yes	Record	Yes	Bluetooth/Ant+
Garmin Vivoactive HR Review	13		13	Yes (with USB=Garmin)	No	No	Yes	Ant+
Garmin 920XT Review	24	19	40	No (terminates)	Yes	Record	Yes	Ant+
Garmin Vivoactive 3 Review	13		13		No		Yes	Bluetooth/Ant+
Garmin Vivoactive Review	10	10	10	Yes (with USB=Garmin)	No	No	Yes	Ant+
Suunto Spartan Trainer Review	10	11	30	Yes	Yes	No	Yes	Bluetooth
Suunto Ambit2 Review	15		50	Yes	Yes	Record	Yes	Ant+
Suunto Ambit3 Peak Review	20		100	Yes	Yes	Record	Yes	Bluetooth
Suunto Spartan Ultra Review	18	17	26	Yes, but can't be worn	Yes	Record	Yes	Bluetooth
Garmin Fenix 2 Review	15		50	Yes (with USB=Garmin)	Yes	No	Yes	Ant+
Suunto Ambit3 Run Review	10	10.5	100	Yes	Yes	Record	Yes	Bluetooth
Suunto Ambit2 R Review	8	7.3	25	Yes	Yes	Record	Yes	Ant+
Garmin 235 Review	11		11	Yes, but no optical HR	Yes	No	Yes	Ant+
Garmin 620 Review	10		10	No (resets)	Yes	Record	Yes	Ant+
Garmin 910XT Review	20		20	Yes, but no display	Yes	Record	No	Ant+
Garmin 310XT Review	20		20	Yes, but no display	No	No	No	Ant+
Garmin 225 Review	10	11	10	No (resets)	No	No	Yes	Ant+
TomTom Cardio Runner Review	8	6.3	8	No (resets)	No	No	Yes	Bluetooth HR
Polar V800 Review	13	24	50	No (terminates)	Yes	Display	Predictive	Bluetooth
Polar M430 Review	8	8	8	No	No	No	Yes	Bluetooth
Polar M400 Review	8		8	Yes, but can't be worn	No	No	No	Bluetooth
Garmin 610 Review	8		8	Yes, but no display	Yes	Record	No	Ant+
Leikr Review	5	6.5	5	Yes, but can't be worn	No	No	Yes (few hours)	Ant+
Epson SF-510 Review	30	30	30	No	No	No	Yes (few hours)	Bluetooth HR
Epson SF-810 Review	20	26	20	No	No	No	Yes (few hours)	None
Garmin 10 Review	5		5	No	No	No	No	None

10 Navigation Features

Review	Color Maps	Breadcrumbs	Courses	To Waypoint	Compass	Reverse course	Beeline to start	Connect IQ	Altimeter
Garmin Epix Review	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes
Garmin Fenix 5X Review	Yes	Yes	Yes	Yes	Yes	Yes	No	No	Yes
Garmin Fenix 3 Review	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes
Garmin 935 Review	No	Yes	Yes	Yes	Yes	Yes	No	No	Yes
Garmin Vivoactive HR Review	No	No	No	No	No	No	No	Yes	Yes
Garmin 920XT Review	No	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes
Garmin Vivoactive 3 Review	No	No	No	No	No	No	No	No	No
Garmin Vivoactive Review	No	No	No	No	No	No	Yes	Yes	No
Suunto Spartan Trainer Review	No	No	No	No	No	No	Yes	No	No
Suunto Ambit2 Review	No	No	Yes	Yes	Yes	Yes	Yes	No	Yes
Suunto Ambit3 Peak Review	No	No	Yes	Yes	Yes	Yes	Yes	No	Yes
Suunto Spartan Ultra Review	No	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes
Garmin Fenix 2 Review	No	Yes	Yes	Yes	Yes	Yes	No	No	Yes
Suunto Ambit3 Run Review	No	No	Yes	Yes	Yes	Yes	Yes	No	No
Suunto Ambit2 R Review	No	No	Yes	Yes	Yes	Yes	Yes	No	No
Garmin 235 Review	No	No	No	No	No	No	Yes	Yes	No
Garmin 620 Review	No	No	No	No	No	No	No	No	No
Garmin 910XT Review	No	Yes	Yes	Yes	No	Yes	Yes	No	Yes
Garmin 310XT Review	No	Yes	Yes	Yes	No	Yes	No	No	No
Garmin 225 Review	No	No	No	No	No	No	No	No	No
TomTom Cardio Runner Review	No	No	No	No	No	No	No	No	No
Polar V800 Review	No	No	Yes	No	No	No	Yes	No	Yes
Polar M430 Review	No	No	No	No	No	No	Yes	No	No
Polar M400 Review	No	No	No	No	No	No	Yes	No	No
Garmin 610 Review	No	No	Yes	Yes	No	No	Yes	No	No
Leikr Review	Yes	Yes	Yes	No	No	No	No	No	No
Epson SF-510 Review	No	No	No	No	No	No	No	No	No
Epson SF-810 Review	No	No	No	No	No	No	No	No	No
Garmin 10 Review	No	No	No	No	No	No	No	No	No

For "navigation":

• Color Maps gives you full color maps, rather like a smart phone, with roads and paths marked out.
• Track Outline is a display of where you've run, rather like a breadcrumb trail. If there are maps, the outline is superimposed otherwise this is just the outline on its own without any context.
• Course Outline is an outline of a route that can be downloaded. I've found this useful during ultras or in unfamiliar cities where I've needed to know where to go.
• Back To Start is a simple arrow point to your starting point, so it won't help you backtrack.
• Back To Waypoint returns you to a previously marked location using a simple arrow to point.
• Compass. A magnetic compass can help you orient yourself or the map. Without a magnetic compass you have to be moving for the GPS to give you a sense of direction.

(Older Reviews: Polar RC3 GPS, Soleus 1.0, Motorola Motoactv.)