Garmin Epix Review

The Garmin Epix, showing a topo map.

The Garmin Epix is the top of Garmin's GPS watch line. The Epix has nearly all of the functionality of the Garmin 920XT, plus support for full color maps. Having a good map display is great for both urban and wilderness runners when they're in unfamiliar surroundings. The Epix includes Connect IQ that allows it run applications, much like a smartphone. Its clear display, real buttons, touchscreen, map display and rich functionality make it one of the best watches if you can afford it and are okay with the poor GPS accuracy and its bulk. For a simple evaluation of a GPS watch, I look at how well it can answer some basic questions:

• How far did I run? This is the most basic question, and sadly, the Epix has rather poor GPS Accuracy, and while firmware updates might improve this slightly, I doubt it will get close to the accuracy of the Polar V800. It looks like activating GLONAS and WAAS improves accuracy, it's still not great. How big a problem this is for you will depend on the type of course you're running, but if this is important to you, look for a more accurate watch.
• 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. Thankfully, the Epix is one of the few devices that will display current Pace From A Footpod while getting all other data from GPS.
• Where am I? The Epix has full color maps, the ability to download a course, and to give directions back to the start. This is as good as it gets.
• 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. Not only does the Epix get Cadence from a Footpod, it will also get it from the Garmin Run Heart Rate monitor. There is also support for Cadence from the internal accelerometer, though I find that's not as accurate. The Cadence alerts are especially useful for keeping you on track.

For ultramarathon running the battery life of the Epix makes it a strong candidate, especially with the mapping functionality. If you hope to be still moving during the Second Dawn, the Epix might be for you. See Watches for Ultrarunning for more details.

Contents

1 GPS Accuracy

The GPS Accuracy for the Epix is poor at best; while it's not the worst I've seen, it's close to the bottom of the pile. Determining if it's acceptable for your running will depend on your usage.

• The Epix can give a reasonable estimate of how far you've run but the errors can add up. The amount of error depends on your route; in straight lines the Epix is okay, though even then it's worse than most other devices. However, on a twisty course it is out by around 0.75 mile on a 20 mile run. That's enough to mess up your marathon training. This translates to errors on your average pace.
• GPS watches are not accurate enough to give you a useful display of your current pace. For that you need the older Garmin 610, Garmin 310XT, or Garmin 910XT with a Footpod. Those devices will allow you to get your current pace from the footpod while using GPS for everything else. Hopefully Connect IQ will allow this to be added to the Epix. (Note that the current pace displayed on the Epix is worse than most watches, often being out by more than a minute/mile.)
• The Epix supports both GLONASS and WASS, but I have not gathered sufficient data to know if they will help accuracy (initial testing suggests not.)

If you want better GPS Accuracy than the Epix, then the Polar V800 is by far the best I've tested.

2 Garmin Epix Pros

• The Epix will display full color maps, which can be freely and easily downloaded from the internet.
• The Epix supports Garmin's Connect IQ, which allows for the creation of apps in much the same way you can run apps on Android or iOS.
• The Epix is larger than devices like the Garmin 620, and it doesn't look like a traditional watch in the way the Garmin Fenix 2 does. However, I have tiny wrists (less than 6 inches) and I found Epix is quite comfortable, with a strap that works better than most I've tested. The Epix fits my wrist far better than the Polar V800 which I have to wear over a sweatband.
• The color display on the Epix has much richer colors than some of Garmin's earlier watches. In other sports watches I don't think that color adds much functionality, but it's vital for the Epix to be able to display maps. The font sizes are mostly easy to read, though occasionally I've struggled. The Epix has exactly the same size and resolution display as the Garmin 920XT.
• Like the Garmin 620, Garmin Fenix 2, and the Garmin 920XT, the Epix will show and record Cadence, Vertical Oscillation (VO) and Ground Contact Time (GCT).
• The Epix can be configured to alert you when a metric is out of range. The alert for Cadence is particularly useful. The Cadence alert will work when it's using the internal accelerometer for Cadence, as well as the HRM-Run strap or a Footpod.
• There is a metronome to help you keep your Cadence where it should be, which is a really nice feature. The metronome can be set to make a sound and/or vibrate. The vibration option is nice so you don't annoy people you're running with. You can set the alert to go off every second, fourth, or sixth beat.
• Like many recent Garmin running watches, the Epix can display the Firstbeat Training Effect, an indicator of how hard a training session is. While I find this useful, it's important to remember that the Training Effect is strongly biased towards intensity rather than duration. (Training Effect requires a heart rate monitor.)
• There is also support for the Firstbeat Estimate of Recovery Time before the next workout, which I also like, though you have to take this with a large pinch of salt.
• The Epix will cache the GPS satellite locations for the next few days to reduce startup time. This is particularly useful when travelling to a new location as older devices can take minutes to get a fix when travelling. I hate standing around on a street corner in the cold, dark, early hours of the morning waiting for my watch to tell me I can start running. In my testing the satellite acquisition was generally very rapid, and the Epix is sensitive enough to get a fix inside my house. However, I have had issues with the Epix acquiring a signal near tall buildings, more so than other devices I've tested.
• There are five real buttons as well as a touchscreen on the Epix, which is a great combination. The touchscreen allows you to press and hold on a displayed value to change it while you're running, something I've really liked.
• The prediction of your V̇O₂max worked well for me, but I would not rely on its accuracy.
• The Epix will upload your workouts to Garmin Connect via USB, or via a smart phone and Bluetooth. The smart phone can upload a workout as it takes place, which is nice for folks tracking you during a race, though it means wearing the watch and the phone together. If you plug the Epix into a computer it will function as a flash drive, giving you direct access to your workouts as '.FIT' files. The FIT files provide compatibility with a huge range of software. One of the few things that are in the Garmin 920XT and not in the Epix is the ability to upload workouts over WiFi, which was nice.
• The Epix will not display Heart Rate Variability but it is possible for it to record Heart Rate Variability for later analysis. To enable this recording, you need to download a special FIT file from the firstbeat.com web site. (There is a Connect IQ app that will calculate HRV, but you can't use it during a workout, something I hope will be corrected in the future.)
• The 24 hour battery life is good enough for many ultramarathons, and the extended mode allows for 50 hours with degraded GPS accuracy. In my informal testing, I found that displaying the map reduced battery life.
• There are various navigation capabilities in the Epix. You can save your current location and return to it later, or take a sighting on a distant object and the Epix will point you in the right direction. TracBack will reverse the course you've run to get you back to your start.
• You can use the Epix as an activity monitor, something that's common to many new sports watches. However, because the Epix is only using its internal accelerometer the activity estimates are rather poor. If you need an activity monitor, I'd recommend the Basis Activity Tracker which has sensors for heart rate, skin temperature and perspiration.
• The Epix will record your personal best performances, such as fasted 5K or longest distance. These are a nice novelty, but for most people you won't be setting PR's on a regular enough basis for it to add much value.
• While the Epix does not have much in the way of graphs out of the box, Connect IQ is being used to add graphs for things like heart rate.
• Because the Epix has room for extra maps, it actually has a good amount of storage space. It's unlikely most runners will ever run out of room for workouts unless they've filled the Epix with maps.
• A minor win for the Epix is it's charging cable; it's the only device where I've found the cable clips into the watch easily and reliably.

3 Garmin Epix Cons

• There is no way of displaying your current pace from the Footpod while using GPS for overall distance and course. Like all GPS watches, the Epix does not have sufficient GPS accuracy to give useful current pace information. For situations where pacing is critical, such as running a marathon, a Footpod works better.
• The Epix includes an internal accelerometer to give you an idea of pace and distance while running on a treadmill without a footpod, but I found the accuracy was rather poor. I have yet to come across a watch that can reasonably estimate your pace from the movement of your wrist, nor does it seem likely that this functionality is practical.
• You need to have the new HRM for the some of the features. The Epix will display Heart Rate and calculate Training Effect with the older Garmin HRM, but not Ground Contact Time or Vertical Oscillation.
• The Epix is not unattractive in a rather plastic way, but it's nowhere near as elegant and stylish as the Polar V800.

4 Comparisons

Here are some of the watches that our competitors for the Epix:

• Garmin 920XT. The Epix has nearly all the features of the 920XT plus the extra mapping and navigation features. I think the Epix is well worth the extra $100 over the 920XT though you have to accept slightly worse GPS accuracy.
• Fenix 3. The Fenix 3 falls half way between the 920XT and the Epix. It has all the features of the 920XT (including WiFi upload), plus some navigation features that might be useful to some folks. However, the main benefit of the Fenix 3 over the 920XT or Epix is probably that it looks a little more like a watch than a brick. I don't think that the Fenix 2 is worth the premium over the 920XT or the saving over the Epix.
• Garmin 620. The 620 has a subset of the features of the Epix and is closer to the 920XT without the Connect IQ. The 620 is a lot smaller, so I'd only go for the 620 over the Epix if size is critical.
• Garmin 610. The 610 is the predecessor to the Garmin 620 and its price has dropped to make it an attractive option. While the 610 lacks many of the cool new features of the 620/920XT/Epix, it performs the core functionality you need is a runner as well as (or better than) the newer devices. When I'm pacing marathons, I still make use of the 610 with a Footpod to keep me on pace. I would highly recommend giving the Garmin 610 serious consideration, even though it's an older device.
• Garmin 310XT. Like the 610, the 310XT is older and its price has dropped nicely. You could think of the 310XT as a larger 610 with better battery life.
• Polar V800. The V800 is a far more elegant watch than the Epix, and is beautifully made. The V800 also has outstanding GPS accuracy, which makes it a strong contender for your money. However the V800 is quite expensive, and its functionality is a little limited. (Don't expect the good GPS accuracy to give an accurate display of current pace – you need a Garmin 310XT/910XT/610 with a footpod for that.)

5 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. You'll notice that the Epix has a rather short list of missing features.

• Web Configuration. Some watches allow you to setup the configuration via a web site, and then download your changes. This is vastly easier than fiddling with the watch.

6 Downloading Maps

This is the easiest way to download maps I've found so far.

• Go to http://garmin.openstreetmap.nl/ on a browser
• I select "Routable Bicycle" which seems to work well.
• Choose the location; in the US, select the state you want under "North America" drop down.
• You can select the locations you want in the menu on the left of the screen.
  • Alternatively you can select specific areas visually by clicking on "Enable manual tile selection", and selecting the tiles. You have to give them your email address and they'll mail you a link when the file has been built.
• Download the file.
• If the download is a zip file, you'll need to unzip it.
• Plug in the Epix to your computer.
• Put the IMG file into the GARMIN subfolder of the Epix.
• The map should be enabled automatically, but you can toggle them on and off in the Epix menus.

7 Visual Comparison

Garmin Epix top	Garmin Epix side	Garmin 920XT top	Garmin 920XT side
Garmin 620 top	Garmin 620 side	Suunto Ambit3 top	Suunto Ambit3 side
Suunto Ambit2 top	Suunto Ambit2 side	Polar V800 top	Polar V800 side
TomTom Cardio Runner top	TomTom Cardio Runner side	Leikr 1 top	Leikr 1 side

8 GPS Accuracy

The Garmin Epix has rather poor GPS Accuracy, which is a shame in an otherwise excellent device.

• Under the bridge the Epix errors even out so the Trueness is quite good, but the precision is poor.
• On the out-and-back turnaround the Epix is poor, but no worse than you'd expect from its overall rating.
• Running in a straight line is a fairly easy task for most GPS watches, but while the Epix does better here than elsewhere, it actually has the worst trueness in a straight line of any watch.
• I not had any issues with the Epix maintaining the GPS signal, though I have had occasional times when it's struggled to acquire an initial signal (Time To First Fix).

You can see the Epix sometimes does okay under the bridge and at other times struggles. It does particularly badly on the twisty section, cutting the corners. It does better, but still not great, with the sharp turn seen on the right side of the diagram. You can see the Epix occasionally having more significant problems, but most of the time the accuracy is merely poor. (This diagram has tracks color coded with green indicating good accuracy through to read indicating poor accuracy, and the lap markers as blue dots.)	With GLONAS and WAAS enabled, you can see the tracks are much closer together, as are the blue lap markers. The twisty section is actually slightly worse accuracy, suggesting rather more smoothing. (This diagram has tracks color coded with green indicating good accuracy through to read indicating poor accuracy, and the lap markers as blue dots.)
This close up section of a zigzag shows the problems the Epix has tracking the course. There is poor alignment between the tracks and the change in direction of the course, and the lap markers are widely spaced. (This diagram has tracks color coded with green indicating good accuracy through to read indicating poor accuracy, and the lap markers as blue dots.)	Here you can see how GLONAS and WAAS have tightened the tracks and reduced the errors. The tracks are tighter and they follow the course much better .(This diagram has tracks color coded with green indicating good accuracy through to read indicating poor accuracy, and the lap markers as blue dots.)
Here the Epix does not display the typical GPS behavior of having the tracks that have the green lines shifted slightly down and to the left, blue up and to the right. The errors with the Epix seem more random and diffuse, thought the lap markers are offset, with the blue and green clustered separately. (This image has the tracks color-coded for direction, with green coming from the right, blue from the left.)	GLONAS and WAS improve the accuracy, but the pattern does not have the coherence of other watches, though the lap markers are still offset, and maybe a little further apart. (This image has the tracks color-coded for direction, with green coming from the right, blue from the left.)

9 Support This Site

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.

10 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.

10.1 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

10.2 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

10.3 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

10.4 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

11 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.)