Suunto Ambit2 Review

The Ambit2.

The Suunto Ambit2 offers good functionality, and with the latest firmware, great GPS accuracy. It's been superseded by the Suunto Ambit3, which has better GPS accuracy, but the older Ambit has dropped in price. 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 the Ambit2 has good GPS accuracy, so this is one thing it does well.
• 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. Without the ability to display current Pace From A Footpod while getting all other data from GPS, the Ambit2 can't answer this question very well. It does better than most watches that rely purely on GPS as it has good accuracy and the Suunto FuseSpeed may help a tiny bit. (That said, I frequently see the Ambit2 out by more than a minute/mile).
• Where am I? The Ambit2 has some basic navigation functions.
  • Course Outline. This 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. Note that there's no "Track Outline" which displays where you've been.
  • Back To Start. This is a simple arrow point to your starting point, so it won't help you backtrack.
  • Back To Waypoint. You can mark a location and use the arrow to point to it later. Again, this is a simple "as the crow flies" pointer.
  • 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.
• 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 Ambit3 supports Cadence via a Footpod or it can estimate Cadence from its internal accelerometer, though I've found the internal accelerometer can be out quite a bit. Sadly it has no alerts for when your Cadence is too low.

For ultramarathon running the high end Ambit2 has the battery life for shorter ultras, but for runners that expect to be moving during the Second Dawn, you'll have to compromise GPS accuracy for the Ambit2 to go the distance. 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.

1 Which Version?

The Ambit2 comes in four versions with different functionality. I think the "R" has the best value for money, but depending on your usage you may want to pay for a more expensive version. If you're a cyclist, the "S" might be worthwhile, though I won't comment further as I focus purely on running usage. If you're an ultrarunner, then I think the "Ambit2" version could be well worth it. (The Sapphire is only worthwhile if you're hard on your gear and want the damage resistance.)

	Ambit2 Sapphire	Ambit2	Ambit2 S	Ambit2 R
Price
Claimed battery life	15 hours (50 in extended mode)	15 hours (50 in extended mode)	8 hours (25 in extended mode)	8 hours (25 in extended mode)
Barometric altimeter	Yes	Yes	No	No
Temperature sensor	Yes	Yes	No	No
Compass	Yes	Yes	Yes	No
Cycling support (speed/cadence/power)	Yes	Yes	Yes	No
Swimming support	Yes	Yes	Yes	No
Materials (face, bezel)	Sapphire glass, Steel	Glass, Steel	Glass, Aluminum	Glass, plastic

2 Ambit2 Pros

• The watch is highly configurable, and configuration is via a web site rather than fiddling with the watch. The Ambit2 can display up to 8 different pages of data, including various graphs.
• You can download or create 'Apps' for the Ambit2, which allow for some degree of extensibility. These are not really applications, but small scripts so the functionality is rather limited. It's nothing like the functionality that Garmin has in their Connect IQ. I have developed two apps that calculate Relative Running Economy for the Suunto Ambit. One calculates a moving average and the other a smoothed current value.
• Data has to be uploaded to the Suunto website movescount.com but it can then be exported in many different formats including TCX and FIT. The Suunto website will also automatically export your workouts to other sites; currently Strava, Training Peaks, and Preva are supported.
• While the standard battery life is not great at 8 hours, you can configure the Ambit2 so it only checks GPS data periodically, which compromises GPS Accuracy but improves battery life. With the "R" version I found that after 20 hours of use with 1 minute GPS checks I had a claimed 61% of battery life left, giving a projected life of about 50 hours, which is rather better than claimed. However, I was careful to avoid changing the display or recording laps in order to maximize battery life. For more details, see GPS Accuracy and Sampling Rate. If you want more battery life, then it's worth upgrading to the Ambit2 which roughly doubles the battery life to 15/50 hours.
• The Ambit2 will download a list of GPS satellites for quicker GPS acquisition. This seems to work well, and when the cache is stale because the watch has not been connected to the internet for a while, GPS acquisition is still reasonable.
• The Ambit2 displays Training Effect, but unlike the Garmin units you have to explicitly set your 'activity class' rather than have the watch work it out automatically. In many ways I prefer having the activity class set explicitly.
• There is also support for " Recovery Time", though it's less obvious than the Garmin implementations which display the value at the end of each workout. The Recovery Time displayed at the end of each workout is for that workout alone, which is rather useless. You can go into the log book to find the cumulative Recovery Time but that's a pain.
• The Suunto web site (movescount.com) has remarkably good analysis and data from the Ambit2.
• I found the materials used for the strap are remarkably soft and comfortable. I'm perhaps a little fussy about my watch straps, and I sometimes wonder if some companies go out of their way to create crappy straps. The Ambit range is the best of any I've tried.
• The Ambit2 can display a map of a pre-loaded course, which can be useful for navigating an unfamiliar route, but it requires forethought and effort.
• You can use the Ambit2 to navigate back to the start of your run, but it only provides an arrow and compass, not a map. (There's no map of your current route in the way that Garmin watches often provide.)

3 Ambit2 Cons

• The biggest downside to the Ambit2 compared to the 310XT/910XT/610 is that there is no way of displaying your current pace from the Footpod while using GPS for overall distance and course. You can only use a footpod by turning off GPS, which is pretty useless.
• The Ambit2 does not have a vibration alert, which is something I miss far more than I'd have expected. The vibration is useful for alerts, as you may not hear the beeping in noisy environments or when wearing headphones. The vibration in other watches is also useful as a confirmation you've actually pressed the lap button.
• Like any complex device, the Ambit2 can occasionally need a reboot. Sadly, while you can shut down the Ambit2 from the menu, the only way of waking it up again is to plug it into a USB power source. This should be a very rare issue, but if it happens to you on or just before a race, you're screwed. (To shut down, press the "Back/Lap" and "Start/Stop" buttons pressed to enter the service menu.)

4 Visual Comparison

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

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.

• 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. (The more expensive versions of the Ambit2 add in an Altimeter.)
• 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.
• WiFi/Bluetooth Uploads. While the automatic upload of workouts via WiFi or Bluetooth to a Smartphone is nice, the upload will typically only go to the manufacturer's web site.

6 GPS Accuracy

With the 2.0.11 or later firmware, the Ambit2 has significantly improved their GPS accuracy. It's not as good as the Suunto Ambit3, but it's still better than most other watches except the Polar V800. The latest firmware does better in every situation except going under the bridge where it has an issue reacquiring the signal and jumps off course. I not had any issues with the Ambit2 acquiring or maintaining the GPS signal, unlike some other devices.

	By contrast, the older firmware has more widely spaced tracks, and as the color indicates, far more errors. (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 of a zigzag section shows how well the latest firmware is tracking. (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 again you can see the older firmware has more widely spaced tracks, and you can see the lap markers are more distributed. (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 the Ambit2 displaying the typical GPS behavior with the tracks that have the green lines shifted slightly down and to the left, blue up and to the right. You can see the lap markers similarly shifted. (This image has the tracks color-coded for direction, with green coming from the right, blue from the left.)	the older firmware shows similar behavior, but to a greater extent. (This image has the tracks color-coded for direction, with green coming from the right, blue from the left.)

7 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.

7.1 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

7.2 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

7.3 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

7.4 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

8 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.)