TomTom Cardio In-Depth Review

TomTom Cardio
4.1 / 5 Overall
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Battery Life
GPS Accuracy
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This is one of the most pleasant reviews I’ve had the pleasure of writing – it is a story of redemption for the TomTom Cardio watch. Previously I purchased the watch from a third-party reseller and wrote a review that pointed out how poorly the watch functioned. I ended up getting another watch directly from TomTom after hearing that there was a small chance I had gotten a defective watch. It turns out that the TomTom Cardio works great and the previous watch I had gotten was in fact defective. Now I’ll review the watch in full detail, talking about the optical heart rate monitor and all the other features that make this watch great.

TomTom Cardio Features

The TomTom Cardio has a very special feature that most watches are just getting to market a year or more after TomTom has – optical heart rate monitoring. The optical heart rate monitoring is the main selling point this watch and it works quite well. On the back of the watch there is a couple special lights and a sensor that calculates the reflected light coming back from your skin and very accurately calculates your heart rate. I have found it to work accurately through all levels of running, during the day or night, and even for obstacle racing.


Another interesting feature, that is more of a clever design side effect, is the main button placement. There is one central button that you can push in four different directions, kind of like for an old Nintendo controller. This is a feature because I can’t count how many times I have accidentally stopped my watch when my wrist bends during a barbed wire crawl or some other obstacle that gets my hand bent fully back. It also makes for a really simple few choices of how to navigate the watch while you are running. To stop the watch takes more than a quick click, you need to hold it for about 2 seconds, so that also gets rid of the accidental stoppages.

The GPS is fairly fast from a cold start but still a little slower than most of my newer Garmin watches. I have a theory that this is based on the frequent GPS updates pushed out by Garmin and the lack of updates pushed by TomTom.

TomTom Cardio Usage

I’m always a little sad to switch between my current GPS watch to the new one I’m reviewing and this one was no different at first. I no longer had a touch screen or the customized screen layouts I was used to. What did have me pretty happy from the get go was the built in HR monitoring. Normally I would only choose to wear my monitor if I wanted to check against a benchmark workout or if I was trying to make sure I ran hard enough or more commonly easy enough (I tend to go too hard without checking myself).  Now I always would have that data available to me if I wanted to peek at it or I could just ignore it. But what this means is that all of my runs now have HR and GPS data from here forward – now technically every run can be used as a benchmark run with context to my previous HR and GPS or just on its own.

As much as I enjoy the seamless heart rate and gps integration the watch isn’t without a few flaws. The simple navigations means that it also has simple screens that aren’t always what you want to see. The actual data screen is very simple and navigated mainly through up and down clicks on the center button. The choices you have are Clock Time, Duration, Distance, Current Pace, Average Pace, Calories Burned, Heart Rate, and Heart Rate Zone. But only one at a time plus the little bar at the top that always has duration and distance. There is also no lap times or alerts at the end of each mile. This is the one of the areas that most Garmin Watches excel with the customization you can choose or choose not to do. 

Another unfortunate problem I found out at a recent obstacle race was that sand or dirt can get stuck in the main button. I was able to wash it out after the race but I couldn’t really navigate the watches menus or stop button when I finished. So that center button being a surprising clever feature I mentioned early also cuts in the other direction under certain circumstances.


And one final small detail that isn’t a big deal to most but something I had grown used to on my Garmin watches is the post run recap on screen. When you end a run on the TomTom Cardio you just get back to the main time screen which is great for letting you know you are done and the battery isn’t being drained any more. But to get to your post run details you need to do the following:


Compared to a watch like the Garmin 620 the tracking was also very similar. Here I wore both watches and I overlaid them in photoshop so you could see how closely they lined up while running through city streets with buildings all around.


Overall I would say using the watch for running outside and even on a treadmill has been great. It’s as accurate as any other GPS watch I’ve used plus always having the heart rate data without a chest strap is just amazing. The charging and syncing to their site online after running is fast and easy with their included USB plug. A cool thing about their charging to the computer is that it doesn’t ask or require you to eject the device prior to unplugging unlike all other GPS or Smart watches.

TomTom Cardio Durability

The TomTom Cardio has held up pretty well to all the running, trail runs, and a few OCR races. It did have the problem I mentioned with sand and dirt getting stuck in the button. I would say that it is functional for OCR but a little flawed, otherwise it will stand the test of time for all other types of running. The battery life seems to still be the same after months of usage and my irregular charging schedule – usually batteries start to show problems in 6+ months so I would love to hear from anyone that has one about the long term battery life.

TomTom Cardio Pros and Cons


  • No heart rate chest strap needed, optical HR built into the watch
  • Multiple watch bands and bike handle bar mount included
  • GPS and heart rate integration looks great on website after syncing
  • Very affordable at only $199.99


  • The in watch interface lacks display options while running
  • A little slower to acquire GPS signal than competition
  • Not very fashionable as a normal watch
  • Some people have issues with HR accuracy – contact TomTom

TomTom Cardio Competition

TomTom CardioGarmin 225Fitbit SurgeMicrosoft Band 2
Battery Life8 Hours4 weeks as watch, 10 hours with GPS7 days without GPS, 5 hours with GPS2 days without GPS, 2-3 Hours with GPS
Heart Rate MonitorOpticalOpticalYes, opticalOptical
Waterproof 5 ATM (50 Meters)5 ATM (50 Meters)50 Meters (no swimming)Water-resistant IPX7, Up to 1 Meter
Weight2.22 oz1.91 oz1.8 oz2.1 oz.
Phone CompatibilityAndroid, iOSAndroid, iOSAndroid, iOS, WindowsAndroid, iOS, Windows
ORM ReviewYesYesYesYes
BuyAmazon Amazon Amazon Amazon

TomTom Cardio Verdict

As of the moment I am writing this review this watch has become my primary running watch. I enjoy not having to think about wether or not I’m in the mood to put on a heart rate strap since it is integrated. I would however want more options and settings that I can change. I like to see more things at once on my watch, especially lap splits at every mile. I would also very much like to have something like an UltraTrac mode that the Garmin’s have. So my final word on this watch is buy it if you want a feature rich watch for an affordable price without the ability to customize as much as other GPS running watches.

Fitbit Surge Review

Fitbit Surge
4 / 5 Overall
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Battery Life
GPS Accuracy

A feature rich watch for a niche audience. If you are in the market for a watch to track your daily activities like steps, heart rate, and sleep than look no further.

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The Fitbit Surge is the currently the most cutting edge watch for the exercise enthusiast. I say “exercise enthusiast” not to be insulting but to say that this watch has all the features most athletes would want. But it does fall short when compared to a watch like the Garmin Fenix 3 that Alec Blenis recently reviewed here. That’s not the worst thing either, this watch isn’t trying to be the Garmin Fenix 3 or any other similar watch, it is in its own space and doing amazing there.

My initial excitement for this watch was for the possibility of having the ultimate quantified self measurements as well as taking care of my usual GPS and heart rate monitoring usage for running. The space for quantified self and smart watches is starting to become more crowded with great options and the soon to come apple watch.

Similar Products

Fitbit SurgeMicrosoft BandBasis PeakApple Watch - Sport Edition
Battery Life7 days without GPS, 5 hours with GPS2 days without GPS usage4 days18 hours
Heart Rate MonitorYes, opticalOpticalOpticalYes, optical
Waterproof 50 Meters (no swimming)Splash Resistant5 metersSplash Resistant
Weight1.8 oz2.12 ozN/A1.41 oz
Phone CompatibilityAndroid, iOS, WindowsAndroid, iOS, WindowsAndroid, iOSiOS
Price$249.99$199.99 - $249.99$199.99$549.99
ORM ReviewYesNoNoBeing Tested
Buy Amazon Amazon Amazon Apple Store

Fitbit Surge Review – Features

The main feature of this watch is the optical heart rate monitor. What this means is that you get heart rate monitor, without a chest strap, through a sensor on the back of the watch. While this technology is cool it is not as reliable as a traditional chest strap. For day to day usage when not working out I would say it accurately tracked about 85% of the time. When exercising at a fairly high capacity it would track about %50-%60 of the time. I have used 3 other watches with this same technology and so far this watch performs the best. It out performed the Basis Peak and the TomTom Runner Cardio by far, these both barely functioned when working out. So in comparison it is great but optical heart rate monitoring still has some ways to go before it’s as reliable as a chest strap.

Another impressive feature is the battery life that lasts for 7 days while constantly tracking your heart rate and steps. This means that it is literally tracking you 24/7 while walking around and sleeping. All it requires is a few hours a week to fully charge or you can just charge it while you shower like I did. When used with GPS it only lasts 5 hours on a full charge.

Unfortunately one area where it falls short is in waterproofing which pretty much rules it out for OCR usage unless you are doing a stadium/urban race. They say it is rated at 5 ATM which in theory means up to 50 meters but then they turn around and say not to use it for swimming. I have ended up going for many runs where I am sweating heavily and it was raining out with no issues at all.

The running and GPS combination is another area where I was not impressed with for high performance tracking. GPS acquires just as fast as any watch but the screens related to running with the GPS on are not intuitive and at the moment they can’t be customized the way I would like. When you use this after using a Garmin with GPS for running you noticed a clear difference in what a real GPS running watch should feel like. One of the main custom screens I use on the Garmin 620 is a lap based screen where it shows my current lap pace, lap distance (mile intervals), and lap time. There are no lap based options on this watch.

Fitbit Surge Review – Durability

The Fitbit Surges durability for every day use it just fine. For obstacle course racing I would say never ever use it. The brushed steel of the main body will scuff easily and leave it looking marred. The texture of the strap band is one that when it gets mud on it and dries will require a significant amount of scrubbing to make it look clean and new again. And finally the screen is completely exposed with no bezel and has exposed some what rigid edges. I gave it a 2 for durability because for many people they might want to just use it for normal exercise which was what I did.

Fitbit Surge Review – Usage

As I stated before, the main usage in my mind for this watch was in a manner similar to quantified self. In this aspect it succeeded and had some really cool charts that you could see online after syncing by bluetooth to your phone/computer or through USB. It would automatically detect things like when you went up stairs compared to normal steps and when you went to sleep without you having to press anything. I think the auto sleep detection was very impressive because it would even recognize a short nap during the day.


For someone that is casually running or biking this will meet your needs for exercise. It will definitely track the distance you move, how long you have done it, and for the most part your heart rate. When I used it for easy to medium effort runs it was very accurate with my heart rate and only cut out optical heart rate monitoring once or twice for short periods. When running hard at near  max capacity and dripping in sweat it would cut out every so often until I shifted the watch a little. I would adjust the position but it could take a bit of time to come back with HRM which is something I didn’t enjoy focusing on while I was just trying to crack out a hard run.

When I used it on a stationary bike it was the most reliable for heart rate tracking. I think this is due to two factors that are unique to indoor biking – no bright sunlight and relatively stationary arms. You can see from this comparison chart that it was right in line with the Garmin 620 and heart strap combination.


In the looks department the Fitbit Surge while feeling and looking slim to the user looks a bit large to the outside world because of its design. You see it tapers from a large size to a thin size closest to you which is very visually pleasing to the user but large looking to the outside world. The strap is also incredibly soft and comfortable to wear for extended periods of time which is a huge plus since you are generally meant to wear this watch 24/7 and only rarely take it for for charging.


Another interesting thing about the watch is its general interface. For the most part you will only swipe the touch sensitive screen for most of your time using it. The buttons are only used to navigate menus and change modes such as changing to the GPS run mode from the usual daily monitoring. It is pretty intuitive and I never needed the manual when setting up the watch or using it.

Where the lack of screens I mentioned when running is redeemed a little is after the fact when you upload your data. The online dashboard and phone app have some really great ways to analyze your data. Look at all the data I get for one day of running errands walking around a little:


And here is what running looks like when seen on the dashboard (those pace drops are traffic lights):


Fitbit Surge Review – Verdict

The Fitbit Surge is a watch that I wanted to love and be my only watch for all of my exercise and life tracking needs. Regrettably while it excels in tracking, it falls short in the exercise area. It is also is not OCR friendly which is a major downside for many of you. What a good solution that I might suggest if your budget is wide open for fitness gear – get this watch for daily tracking and a Garmin or Suunto for your OCR and workout needs. Or if you are lucky enough to already have a sports style GPS watch, just get this to track your daily life if that is something you are interested in like I am. If you own one make sure to leave a mini review below!

Fitbit Surge Pros

  • 7 day optical heart rate, step,  and sleep tracking on one charge
  • Automatic Sleep tracking
  • GPS for the occasional run
  • Nice Dashboard to view data
  • Easy bluetooth syncing

Fitbit Surge Cons

  • Short GPS battery life compared to Fenix 3
  • Limited Running Activity Screens
  • Not as Durable as I would like



Garmin Fenix 3 Review

Garmin Fenix 3
5 / 5 Overall
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Battery Life
GPS Accuracy

The Garmin Fenix 3 is nothing like it’s predecessors, the Fenix 1/2. While the hardware on those models was pretty cool and rugged, the software wasn’t. This version changes all of that.

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As one of the more highly anticipated new products from the most popular GPS device manufacturer in the world, there are hundreds if not thousands of online reviews, hands on tutorials, and unboxing videos for the Garmin fenix 3 available all over the web. That’s not what this article is about though. You’re here because you’re an obstacle course racer and tnt to know if having a fancy watch will help your racing and training, or if you should just stick with the Strava phone app and a naked wrist on race day. While sometimes I do love to ditch the technology and just run, it’s undeniable that real time feedback, post workout analysis, and the “I spent $500 on this watch, so I should probably go run with it” feeling, can help you tremendously as you plan future training, evaluate race performances, and stay motivated.

But obstacle racers don’t just want the basics, do we? Why have a water resistant watch when it can be waterproof to 100M? Why settle for GPS elevation when you can have a barometric altimeter? Why settle for 32 GPS satellites when you can have 24 additional GLONASS satellites at your disposal for even better data? This is by no means a budget-friendly watch, but if you’re in the market for what might just be an obstacle racer’s dream watch, then the Fenix 3 might be the one for you.

The Big Things

Although its name suggests otherwise, the Garmin Fenix 3 is nothing like it’s predecessors, the Fenix 1/2. While the hardware on those models was pretty cool and rugged, the software wasn’t the most user friendly for runners, cyclists, etc. As such, the Fenix line has historically been more popular among hikers because of it’s navigation features, while the Garmin Forerunner series has been popular among runners because of it’s streamlined software and ease of use, despite being a bit clunky. I used to own a Forerunner 910XT and absolutely loved it; the software was great, never had any bugs/issues…it just worked. I only traded it in for the Fenix2 because I thought it looked super cool, but was disappointed by the software and all the bugs I encountered. I had decided that I would trade it in once the next generation Forerunner watch came out, but when I learned about the Fenix 3 I changed my mind. The Garmin Fenix 3 actually builds upon the software of the Forerunner and, internally, is quite similar to the top-of-the-line 920XT, yet is housed in an improved exterior of the original Fenix. As such, software issues = none. This may seem a small thing, but it is incredibly frustrating for your watch to freeze 12 hours into a 15 hour race and then get crappy data for the coolest race you’ve ever done. You should get what you pay for, but with the Fenix 2 you didn’t; frequent software crashes is unacceptable on a $400 device. So, it’s worth repeating, the Garmin Fenix 3 has awesome software!

You know what else is awesome? Daily activity tracking. Unlike most (any?) high end GPS units on the market today, the Fenix 3 tracks your sleep, steps throughout the day, and more. I never realized how cool functionality like this could be until I started using it. Admittedly, this data would be far more useful if you were also tracking your heart rate 24/7 (like some activity monitors can do), but it is still useful and motivating to see these metrics, even if they could be improved.

Also awesome: widgets! The Fenix 3 isn’t the first watch to have downloadable apps/widgets, but Garmin has the potential to do it very well. Currently, the IQ store where you download them has just launched and options are limited, but there are already some very cool apps you can download right to your watch. As a physicist, I particularly like the one that calculates the velocity-dependent relativistic time shift that accumulates during your activities. Yes, that one is totally pointless, but it just shows how the sky’s the limit with these widgets. I expect to see lots of very interesting ones available soon.

Garmin Fenix 3 review

Widgets and WiFi (aka Nerd Porn)

Another big thing that’s new (and improved) to the Fenix 3 is wireless connectivity. Wifi uploading is totally new to the Fenix lineup, and it truly is amazing if you’ve never experienced it yourself. Like magic, you finish an activity, walk in your house, and it automatically uploads without pressing any buttons or plugging in any wires. And if you have a smartphone, you don’t even need to get home. Simply pair your phone with the watch over bluetooth, and you can auto-sync activities that way too. While bluetooth connectivity isn’t new to the Fenix line up, with the Fenix 3 it works much better than before. The impact on battery life is minimal (before, it was a big drain), the uploads speeds are super fast, and with the IQ store for widgets, it’s really easy to download a new app, widget, or watch face, and instantly send it to the watch. Yes, you can download new watch faces, so you can display analog, digital, or something custom in between, while in watch-mode.

While battery life may not be critically important for most athletes, it’s a necessity for anyone planning on doing a long race or ultra. Even if you’re not, it’s convenient not to have to charge it all the time on a day to day basis. The Fenix 3 boasts the best battery life yet with 16-20 hours of use in normal GPS mode, and up to 50 in ultra trac mode (a less accurate but more efficient mode for multi day events). Not only is the battery great, but everything about the watch is built to last. Solid exterior, waterproof to 100M, and buttons that aren’t easily clogged by mud. As an obstacle racer, you couldn’t ask for better hardware. It’s thinner than previous models and probably the most durable GPS watch out there. It will probably last longer than you, but in case you plan on running over 50 hours, it has the ability to charge while still recording an activity, so you could put it in your pack plugged up to a solar panel and keep moving.

Other Things

I could write for days about all the features that the watch has to offer, but most aren’t super relevant to obstacle racing. In addition to what’s discussed above, some key features that you’d want to pay for as an obstacle, trail, or mountain athlete include the barometric altimeter and auto-climb feature. Altimeters are pretty common on most high end watches, but many people don’t know what they are or how they work. Instead of using GPS to determine your altitude, the watch uses changes in air pressure to calculate changes in altitude. Depending on the calibration, the actual value it gives you for your altitude may not be perfect, but it’s far better at determining changes in elevation than GPS is. For this reason, especially on trails and in the woods, watches with barometric altimeters are superior to GPS-only devices, as you’re going to have much more accurate data. Generally speaking, GPS will give you an underestimate when it comes to elevation gain. The only thing to consider is that brief water submersions can cause unusual spikes in elevation since the watch can’t tell the difference between air pressure and water pressure. Just be sure to subtract out these spikes in your head (looking at the graph) before you post to Facebook about how you just climbed a million vertical feet. The video below is a quick demonstration of how much a quick water submersion can throw off altimeter readings, but also shows you two other cool things about the watch. The data field “GA pace” is grade adjusted pace, showing the pace you’d be running if you were on flat ground instead of an incline – this is one of many cool data fields you can download to the watch that don’t come standard. Also, the virtual ascent out of the water bucket triggers the auto climb feature for which the display inverts colors and changes the information displayed. Everything from the sensitivity, to the trigger rate, to the data fields displayed can be modified to your preferences.

Obviously, the Fenix 3 has a barometric altimeter, but you can also adjust the calibration settings manually and view your elevation graphically, rather than just see a number. Using this data, the Fenix 3 also has an auto-climb feature that I think is really cool. When enabled, the watch will change displays when climbing above a certain rate (adjustable), then switch displays back to normal when on flat ground again. It’s pretty neat for the watch to automatically switch from displaying time/pace to altitude/grade once you start going up a hill. That’s pretty much the theme with the Fenix 3: even with the most basic features, they do a great job making it customizable, user friendly, and aesthetically pleasing.

Another big reason to pay more than a hundred bucks for a watch is heart rate tracking. I think that the run dynamics metrics such as ground contact time and vertical oscillation distance are interesting but generally useless data, but you can do a lot with heart rate information. With just your heart rate, you can train more effectively by monitoring time spent at certain intensities, which is great for knowing how hard you’re really working. The Fenix 3, like other high end watches, takes this a step further. Using your heart rate data and workout history, they calculated predicted race finish times, tell you how much you got out of a workout (“training effect”), estimate your VO2 max, and say when you’ll be recovered for your next hard training session. It can be a bit overwhelming to always be doing heart rate training and, I admit, it takes a lot of fun out of it sometimes, but it is a great tool to have in your toolbox, and the Fenix 3 specifically does a great job at making the most out of heart rate data if you provide it.

Is the Sapphire Edition worth it?

The Garmin fenix 3 Sapphire costs $600, when in stock, so I get this question a lot. Is the sapphire display and metal watch band worth the extra money. From a functionality perspective, absolutely not. With the metal band, the watch is more than twice as heavy (175g vs 85g), and the display on the standard edition is honestly good enough. That said, the sapphire has the look and feel of a nice watch that you could wear to social events besides a group run. If you plan on making this your daily watch to wear around town, to work, and to workout, you might want to consider getting the sapphire edition because it does look pretty sharp. I do actually prefer the rubber band for workouts, as it’s easily adjustable and much lighter, but again, the metal does look great.

Garmin Fenix 3 review

 This guy needs the Sapphire Edition. Do you?


After spending the last few weeks testing out the Garmin fenix 3, I’m confident in recommending it to anyone who can rationalize the high price point. You do get what you pay for, and in this case, that’s a lot. It’s a great watch that can do just about anything you could want it to do. There are a few very minor things I’d like to see added in future software updates, but otherwise, this is an obstacle course racer’s dream watch.

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Dario is a long time distance runner and OCR athlete. When not on the roads and trails logging miles he can be found drinking coffee while reading bad science fiction books.
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