Review: Garmin 910XT Triathlon Watch Real World Testing

Chas Reviews 4 Comments

I’ve owned the premier triathlon watch for some time now, and my reviews have been spread over several entries. In order to collect all the information into one article, I’ve reposted them all here (and edited it all together). I’ve also updated the information for firmware 3.0, the latest update to the watch that not only added Garmin Vector support, but improved stroke count and some other issues. Instant pacing, however, has yet to be fixed. . A more in-depth review and more photos can by found at DC Rainmaker’s blog and he is quite thorough. So I’m not going to reinvent the wheel, here, but rather report on my experiences. I’ve been posting some “real world” information on using Garmin‘s 910xt flagship product.

Garmin recently announced the 920xt. I’ve pre-ordered one and will review it once it arrives. Stay tuned!

Open Water Testing

Today I had the chance to take the Garmin 910xt on a swim in open water. This is where the Garmin really starts to shine as opposed to its earlier cousin, the 310xt. With the 310xt,  the map was much more ragged and all over the place. Now, the lines are relatively straight – which is probably a bit of a lie, since I know I don’t swim that straight. But, fortunately, Garmin provides even more information than before, including strokes, strokes per minute, and other data that will be a wonder to see and help me improve my otherwise sloppy freestyle.

  • Despite not having much trouble getting the wetsuit off around the watch, I wasn’t as nimble as he was. My attempt had some troubles, however, you CAN get the suit off with the watch on. However, it’s going to take practice.
  • Once uploaded to garmin connect, then exported, then uploaded to trainingpeaks, the data looked just about identical.
  • The watch is rather easy to read underwater – even in open water. It’s going to take some practice to be able to look without seriously slowing my progress, as slow as it is, however.
  • I rarely got a buzzing of “Lost GPS signal” despite my loooong slow strokes and the watch being underwater a considerable amount of time.
  • In my Half Triathlons and Full triathlons the watch has been about .2 mlies short of the actual distance, although it was pretty accurate in the 2013 Vineman

Bike Testing

Here is some more information from my test use of the new Garmin 910xt. Today, I had a chance to try the multisport function briefly, and take it for a quick ride on my Giant TCR.

  • As of firmware update 3.0 and 2013, the following complaints have been solved.
  •  GPS-based speed on a bicycle lags behind actual speed considerably. I had a chance to put the 910xt on my bicycle with a Cateye computer, which uses a magnet on the wheel to evaluate speed. This is a problem inherent with GPS and not really with the device. What I’m curious to determine is what will happen when I sync it with my ANT+ speed/cadence sensor. Hopefully, the device will automatically use the ANT+ sensor to display speed rather than the GPS. During my test ride, the GPS was accurate during consistent, straight-forward riding. However, any turn or any change in speed caused the speed to read inaccurately by as much as 2mph until things stabilized again.
  • Again, no GPS issues, although I did notice a difference between my Garmin 310xt GPS results and that provided by the 910xt. The 310xt appeared more accurate, but it’s really too early to make that statement. However, so far I’m not having the GPS accuracy issues I’ve heard about from other users.
  • No problems today with the altitude – it was dead-on accurate today, and the GPS was on the entire time, too. It was, in fact, more accurate than @trainingpeaks “elevation correction” function
  • The Garmin still does not play well with Device Agent or Trainingpeaks, although I have heard from their support that they are working hard at catching up with the device. Essentially, if you do a single activity (except swim), the device will save a .tcx file. However, anything else, and it only saves a .fit file, and you have to save to Garmin Connect, then export, then import to Trainingpeaks – a big pain. I’m sure there will be an update coming on that, where (hopefully) trainingpeaks will better handle .fit files natively in the future. Although you can use the .fit file to upload to trainingpeaks, it has limitations – when I uploaded my multi-sport .fit file, it only accepted the bike portion (the run disappeared).
  • I love the display of the new watch. It’s very clear and easy to read, and “appears” bigger than the 310xt. I’m not sure if display is bigger or not, but it sure seems that way!
  • The back-light of the watch is a bit different from the 310xt. During a night run, the light was neither better or worse, but it was “different”. Hopefully, it uses less battery!
  • The buttons seem harder to use on the bike than the 310xt, but that’s probably because I’m not used to it yet. I had the same trouble with the 310xt when I first got it. As of 2013, I don’t have any complaints anymore. It was indeed just necessary for me to get used to the buttons.
  • Initially, the 910xt had issues with turning off during descents or high speed rides with vibrations. As of firmware 3.0, I’ve never had the issue occur again.

Test Run

Today I had my first chance to use the Garmin 910xt on my first run since I over-stressed my back. This is only the first test run (a run test?) so your results may vary.

  • The new Barometric altimeter has some issues but they aren’t insurmountable. As a pilot,  I knew variations from a standard atmosphere (ie, anything other than an sea-level pressure of 29.92 inches of mercury) would cause an error in the altitude, but it would be consistent at least through the run. Oddly, that doesn’t seem to be the case, as, at least as it recorded on, if the GPS is off, the altimeter was fairly accurate. Once I turned the GPS on, it was accurate – except for reading -400 feet below sea level. So I’m not sure where the error was, but something wasn’t right with the altitude data. As of 2013, I still have altitude issues but more on my indoor workouts. For some reason, Garmin keeps thinking that I’m climbing hundreds of feet while doing FocusT25.
  • Moisture on the INSIDE of the bezel formed during my run in California. It was a nice day and not very humid. Fortunately, exhaling on the bezel caused the moisture to disappear. It returned a couple of times while running, but after exhauling on it three times, it went away and stayed that way. Of course, the moisture formed right in the middle, in an oval, in just a way to block all the information I wanted to read. Since my initial runs, I’ve rarely had this problem again. It seems to reoccur occasionally, but only on a rare occasion.
  • The GPS accuracy was pretty accurate for me, although others have reported GPS accuracy issues. I had the GPS off for the first mile of the run, and the 910xt happily used the footpod and the calibration to figure my distance.
  • The footpod calibrated slightly differently, but I suspect the algorithm remains the same. Probably a difference in my cadence. The footpod remains inaccurate as I’m not a heel-strike runner. I’ve noticed in the last year that if I purposely strike heal first, the footpod is fairly accurate. But stepping mid-foot causes it to be accurate only on a calibrated single pace.

Using Courses

Recently I’ve begun using the “courses” function of the Garmin 910xt more extensively. Although an interesting gadget, the “courses function” has issues that sometime reduce its effectiveness. However, it’s still fun to use, and you can ‘race’ yourself, or a buddy, on your courses that you’ve either created or actually attempted. There are some things to think about when using the courses functions, however.

  • You have to turn on “Virtual Partner” in order to use the “Virtual Racer” graphic page (the one showing how far behind/in front of the “other guy/gal” you are). The “Virtual Partner” function turns into “Virtual Racer” when you add a course. For some people, that might seem obvious, but because the Garmin 910xt adds additional screens automatically when doing a course, I thought it would also automatically add the “Virtual Racer” page showing how far in front/behind I was from my previous attempt. It doesn’t until you turn on Virtual Pacer, which then works like you’d expect. Ya, probably a “Duh” moment, but I like to think I’m not the only Homer Simpson on the planet…
  • The watch seems somewhat intolerant of being “close” to GPS waypoints. Whether I’ve done the course before, or mapped it out on Garmin Connect, I get “Off Course” warnings fairly consistently. This gets annoying during a four hour bike ride. That said, it does amazingly manage to figure out where you should be in your virtual race once it “re-acquires” the course.
  • I do like the little “YOU WIN!” window that pops up if you finish ahead of your “opponent” in the virtual race. I haven’t “lost” yet but I suspect the “YOU LOSE!” window will not be as well received when I get one.
  • Mapping out a course for the Garmin is not as easy as you might think. The Garmin Connect website does a good job, but other third-party sources seem to be stuck in a time-warp from 3-5 years ago. Googles recent advances with bike routes and bike maps certainly helps, and hopefully more maps that can export .tcx files easily will come available in the future. For now, the Garmin Connect website is by far the best and easiest one to use for me so far.
  • If you take a shortcut, the watch does warn you once that you are off course. If you later rejoin the route, it will pickup where you rejoin and tell you where you are in relation to your “opponent”. Nifty!
  • I’m still not convinced just how “useful” this function really is in the real world. The course has to be exact, and the weather should be exactly the same to get any real benefit. It does, however, keep you handily  distracted, and I probably pushed myself harder (while maintaining the appropriate heart rate zone!), so there may indeed be benefits. If you’re wearing a Garmin 91oxt, most likely you’re a competitive person, and racing yourself can be excellent motivation. It also gives you lots of data to help compare your progress, but outside factors can effect that greatly (weather, for example).
  • It takes a long time to “load” longer courses (my longest was 65 miles) and then to figure out where you are in relation to the start point. So, if you’re impatient like me, make sure to select “Do Course” before you pump up your tires, take the bike off the car, put your helmet on, etc. Don’t wait until you’re on the bike ready to ride. You’ll find yourself waiting several minutes tapping the ground annoyed if you don’t. Once the watch does all it’s figuring, though, it keeps up fairly well
  • The “elevation” profile map is useless in the “Fast Scroll” mode. I wish there was a way to turn it off – it take the watch too long to “think” before it can draw the map. If you manually change pages, or perhaps on “slow scroll” it might work better. As it is, the elevation function map just is too complicated for the computer.

Overall, it’s a nifty feature for the watch, but I would have preferred more work go into the swim and GPS accuracy issues. Not sure if that would have been possible and since this sort of thing merely requires a smart computer doing what computers do well (math), I am glad they included the function. Besides, I’m still playing with it – so that has to count for something!

I had the chance to use my Garmin 910xt on a 50mile bike ride along Route 1 of the California coast:

I created a route on, which doesn’t allow exporting the .crs files that Garmin Training Center needs to export to the watch. Fortunately, there is a website,, which will convert the .gcx file so you can export to a .crs that the Garmin 910xt likes to use. The details on how to do all of the above is another whole article which really isn’t the point here… We’re talking about how “Courses” work in the wild on the Garmin 910xt.

Note: Garmin Connect now has the ability to build courses on its own site, and the mapmyfitness site is not as easy to use as it used to be. In retrospect, I should have used Garmin’s site instead. 

In the “Map” mode the function works fine and I love the little compass with a pointer. The breadcrumb map is handy, also. Unfortunately, either due to the conversion, or something else, I consistently got “Off Course” indications on the watch – followed seconds later by “Course Found”. This could be due to the GPS coordinates – either too many of them, or not enough, or an inaccurate GPS receiver (which shouldn’t be the case as I was out in the open for the entire ride).

Also, I like to have my pages (or “Data Fields” as Garmin calls them) scroll quickly from one page to another. In “Course” mode, the watch displays a little map of the elevation/breadcrumbs… If it ever had enough time to display it. With a fast scroll, the map page is always “Drawing” and becomes completely useless.

The last issue during my 50mile ride was at the beginning. Since I didn’t start exactly at the start point, it had a hard time initially knowing when I was on course, and joining up with the course. After stopping and restarting the watch as a new course, once on the course, it did fine.

In Summary:

The course function on the Garmin 910xt is a nifty feature, but I found it more annoying than helpful when creating the route through a third party website. The constant on/off course made it fairly unusable. This could be do to my own non-understanding of the function, though. However, the “Virtual Racer” – using your own workout file as a course and racing yourself – might work considerably better. I just don’t know.

I’ll be returning to the route using my own course and racing myself in the future. Doing that, I’ll let you know how the “virtual racer” function works. Hopefully extremely well!

Half Ironman Testing

On May 5, 2012 I had the opportunity to put a Garmin 910xt through a test during the Napa Valley Vintage Triathlon, which is the same as a 1/2 Ironman – 1.2 mile swim, 56 Mile Bike, and a 13.1 mile run.


The Garmin 910xt makes much prettier pictures than its predecessor the 310xt, as you can see from my race report. However, there are two things I find very annoying:

  1. You can’t display your swim distance in miles or tenths of miles. Eventually the watch now converts the distance to miles from yards at a certain point.  Also, it will not display your pace in mi/hr, which I use to judge my triathlon pacing. The 310xt does that.
  2. The algorithm is not optimized for slow/poor swimmers. As a consequence, the Garmin way underestimates the distance I swim. This could be to my slow stroke count (or as I like to say, my long, smooth strokes). At the end of the swim, the map showed a pretty triangle (much prettier than my actual swim I’m sure), but also underestimated the distance by almost .3 miles, or 528 yards – not a small amount. Knowing this going forward doesn’t make the watch less versatile or useful, but it’s good to know. The latest firmware update has addressed many of these issues – so they claim. I haven’t had a real chance to test that except during Vineman… In the real world the GPS was pretty accurate and off by only a small fraction.
  3. In Open Water, at least with my skill set, I find the 310xt actually performs better(with the new firmware that is no longer true) even though the end pictures don’t look as nice. It might be the accelerometer that is throwing of the 910xt since my stroke rate is so slow. I suspect the 910xt would perform or even does perform better with better swim mechanics.


This complaint has apparently been solved by firmware 3.0

A quick search of the internet shows that the 910xt has a problem with (apparently) vibration. During a steep descent at high speed (approximately 40mph) the unit, which was mounted on a Garmin bike mount (universal), turned itself off after I noticed a few glitches on the speed page (showing 0.0mi/hr). Fortunately, turning it back on and hitting start the unit picked up where it left off and I didn’t lose any data or the overall timing of the event. Other than losing about 2 minutes and a couple of miles, the unit was fine on the bike. For someone considering the 910xt, however, most users have chosen not to buy or use the QR (quick release) kit because of shutdown issues that appear to be related to vibration. Keeping the watch on the wrist seems to minimize the shutdowns. Personally, I’ve noticed the unit randomly shut itself off when just sitting at idle not doing anything, but I thought this was a feature to prevent you from completely draining the battery if accidentally turned on while packed in a suitcase…

Except for that one annoyance, the unit did just fine throughout the bike.


Since I’m training for an Ultramarathon in South Africa, I’ve used the watch mostly for running and in that it did fine. I do really enjoy the fact that even in multi-sport mode, it remembers the settings for each event so you don’t have to reset your data pages or anything else. Many other users have noted an issues with the instant pace on the watch, but I don’t use it so can’t really comment. I can say that using the footpod for instant pace hasn’t been very accurate despite numerous attempts to calibrate the footpod with the watch. This continues to be a problem through 2013. I haven’t gone to a track to do the most accurate method, but when I do we’ll see how close it gets.


Garmin has done an excellent job of addressing a lot of the early complaints with the watch. Which goes to show, when you buy the 910xt, make sure to update the firmware. Sure, the watch still has a few issues. That said, it’s still one of the best investments in my training and you’d have a hard time getting me to do anything without it. For me, it was more than worth the investment, and I’d still recommend the product with caveats: Know your limitations, know the devices limitations, and look for firmware updates to improve the product moving forward. Decide what’s best for your goals and your training and just how serious you are about those things (if you’re not writing blogs about races and trail reports and only do triathlons occasionally, this might not be the product for you – there are cheaper and in some ways even better options for you).


Comments 4

  1. Pingback: Garmin 910xt Arrives; Has Some Troubles | captainchas

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  3. Pingback: Garmin 910xt Review: Open Water Swim Test | captainchas

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