Runs and Places

Running Gear Review: Timex Ironman OneGPS+


About a month ago, I received an Ironman OneGPS+ Watch from Timex Sports to wear during my runs and review.

Believe it or not, but even though I’ve been a runner for over 15 years, this is actually the first GPS watch I’ve ever owned. For about the last five years I’ve tracked my runs by bringing my phone with me in an armband and using a running app. Before that, I pretty much just drove around in my car ahead of time and watched the odometer to figure out what the mileage was for different routes I wanted to try. Back then, I kept track of my pace by either using a regular wristwatch or by going the old school route and checking my kitchen clock before I left for a run and then checking it again when I got back.

So the first question I wanted to answer when I got my OneGPS+ was: “How accurate is this thing, really?” So I ran with it almost every day for a month. I ran a few different routes and made sure to run each route at least twice to see if the results were the same. Result: OneGPS+ was extremely accurate and consistent. The distance it recorded on every run that I did matched the distances when I checked them against Google Maps. The recorded distances were also exactly the same when I ran the same route more than once. Even when I tried to trick it by running a few extra steps or shortening the route a little bit, my OneGPS+ would still catch the subtle 0.01 mile differences.

I also did a few runs with both the OneGPS+ and the running apps on my phones to pit them against each other and see which one was more accurate. The results: not only was my OneGPS+ more accurate, but in some cases, the running app on my phone was off by up to a half mile.

My OneGPS+ recorded this:

While my phone recorded this:

There’s actually a good explanation for this:

The way a running app works (on any device) is by periodically making calls to low earth orbiting GPS satellites to determine your current location. Once the app knows your current location (call it Point B), it compares it to the location it retrieved the last time it checked (call that Point A). Then it does a bunch of different calculations to figure out how you got from Point A to Point B, how fast you’re moving, and a few other things like how many calories you’re burning if it knows your weight, etc… The more frequently the measurements are taken, the more accurate the results are going to be. Makes sense right? I can claim some subject matter expertise in this area because about a year ago, I wrote a demo app that shows how this process works (feel free to test it out here if you want to). I’ve also served in advisory roles for a couple tech companies that make apps that use geolocation to track runner movements.

So here’s where running apps on mobile phones run into an issue:

Like I mentioned earlier, the more frequently your running app can retrieve your current location to do its calculations, the more accurate the results will be. The problem with your phone is that it’s doing a lot more than just tracking your runs. It’s also checking for new phone calls, emails, text messages, social media posts, notifications from other apps, available updates from your app store and a variety of other things. The operating systems in most mobile devices are multi-threaded, which means that they can do a lot of different things at the same time…. but there’s still a limit. So what happens if your running app wants to check your location at the same time your phone is already doing a bunch of other stuff? Actually, there’s no way to predict what will happen. The programmers who designed your phone’s operating system and its apps get to decide what processes should have higher priority than others and they include that in their code. So whether or not your running app “wins” depends on what priority it was given compared to your other apps.. If your phone’s operating system decides that checking your location is less important than whatever else it’s doing at the time, then your running app will just have to wait. If the app has to wait too long, it will simply abandon the process and try to check your location again next time. This means that when your phone finally does retrieve your current location, it’s calculations are probably going to be slightly off. Not very much, mind you, we’re talking maybe thousandths of a mile here…. but over time, that adds up. If you look at the graphic of what my phone captured above, you’ll notice that some parts of the route are gray. Those are the areas where for one reason or another, my phone wasn’t able to retrieve my location and had to do a best guess to figure out what it was.

GPS watches don’t have that problem because they don’t have as many other processes going on internally. The OneGPS+ can play music and receive messages but its primary focus is location tracking. I can guarantee that the programmers who designed the watch’s operating system made sure to give its GPS related processes the highest priority possible.

Wow that was a lot of technical information. Hopefully I didn’t put anyone to sleep with all that. Now that we’ve established why a GPS watch is better at tracking runs than a mobile app, let’s talk about some of the other features of the OneGPS+

  • During runs, the OneGPS+ has multiple options for things to display. My favorite screen is one that shows your distance, duration, current pace, and average pace per mile. There’s another screen (accessible by swiping the watch face with your finger) which shows your total number of miles and a third screen which shows just your time and pace.
  • The OneGPS+ is extremely lightweight. The band felt awkward at first but to be honest, I think that’s just because I haven’t worn any type of watch in a long time. By the third run, I felt perfectly comfortable wearing it and now I barely notice it’s there. It’s a lot more comfortable than a bulky arm band holding my phone.
  • The OneGPS+ allows you to store a list of your contacts. You can also send messages from your phone and even designate people as angel contacts who can help you in an emergency. If you need help from an Angel contact, the watch will send them a message along with your current location. OneGPS+ users can also give their contacts the ability to track them in real time. The coolest part of this is that you can grant or deny this access to individual contacts.
  • OneGPS+ users create accounts on There’s also an app you can download on Android and iOS devices. The account allows you to keep track of your contacts follow other OneGPS+ users and send them messages. You can also use it to track users in real time while they run (assuming they’ve allowed you to in their settings). The site also stores the history of your runs and allows you to set up integrations with other popular running and social media apps like Runkeeper, Strava, and Facebook. The site doesn’t integrate with Nike+ or MapMyRun but I have a feeling that that has more to do with legal issues than technical ones (i.e. those companies might see Timex Sports as a competitor and not want to open their APIs to them – I’m not 100% sure about that one, but it would be my guess).
  • Your Timex account also gives you a free year of AT&T data which starts as soon as you complete your account setup. This is how the watch synchronizes your runs with the Timex servers. After the year is up, you can renew your data plan for $40 per year, which is not a bad price. AT&T is the only provider you can use for this, but they have really good coverage. I ran in a variety of different areas with my OneGPS+ watch, some of which were pretty rural, and I never had any issues with coverage or synchs failing. Also, as a side note, you don’t have to have an AT&T phone to be able to use this service. The OneGPS+ operates separately from your other mobile devices.
  • You can also load music onto your OneGPS+ and play it while you run. I have to admit that this is probably the only feature I haven’t tried yet. That has more to do with the fact that I don’t generally listen to music while I run than any concerns about functionality though.

As far as battery life goes, I did a few tests on my OneGPS+.

  • First, I charged the battery up to 100% and then waited to see how long it would take for it to go dead. It lasted three days, during which time I did four runs. Not bad at all.
  • I also waited until the battery was almost dead to go for a long run so I could see what happened if the battery died while I was running. The watch gave me an alert when the power level was at 20% (both from within the watch itself and via an email sent from my OneGPS+ account). About an hour later, the battery finally completely drained and the watch powered down gracefully. After I charged the watch and powered it back up, I checked to see if it had saved the portion of my last run that it recorded before the battery died but it didn’t. And that’s fine – I really didn’t expect it to. I just wanted to see what would happen. It’s a good thing to keep in mind though – if you’re planning to go for a long run, make sure your watch has enough of a charge to last for the entire run.

Speaking of charging, the OneGPS+ has a special power cord with an alligator clip that attaches to a set of terminals underneath the watch face to charge it. The downside of this is that since the watch doesn’t have a standard USB interface, if you travel somewhere with it, you’ll have to bring an extra power cord, which means one extra thing to carry around and keep track of. The flipside of that though is that I completely understand why the engineers at Timex designed it that way: standard USB interfaces are nice, but they create openings in your electronic devices that rain, dust, dirt, sweat and a variety of other things can enter through and wreak havoc on the components inside. The Timex charging interface is a closed design which will help prevent long term damage to the device.

I have a lot more that I can say about the OneGPS+ but this post is getting long and I still have one last thing to cover (keep reading because the best part is coming up). Long story short: I absolutely love my OneGPS+ and even though I’ve only had it for a month, I’m honestly not sure how I managed to go so long without having one. I’d recommend this watch to anyone.

Now for the best part of this post:

In addition to sending me a watch to try, the people at Timex Sports have been awesome enough to let me give away a free one to one of my readers…. So if you’re reading this post, and the OneGPS+ sounds like a pretty cool watch (which it should – it’s awesome), you might be able to get your own for free. Not a bad deal since these watches retail for almost $200.

So what do you have to do to win? It’s pretty simple actually:

If you’re not subscribed to my blog, enter your email address in the upper right hand corner to subscribe.
If you’re subscribed already, send me an email to let me know you’re interested in entering the contest (and make sure to send it from the email address you subscribed with so I’ll be able to verify your subscription).

That’s it. I’ll select a winner at 9:00pm CST on September 15, 2015 and contact you by email to get the rest of your info…. then you’ll have 48 hours to reply or I’ll have to pick someone else. Everyone who subscribes to my site gets a free electronic copy of my book, so if you aren’t already subscribed, then even if you don’t win, you’ll still get something. Good luck!

This post is sponsored by FitFluential on behalf of Timex.

2 thoughts on “Running Gear Review: Timex Ironman OneGPS+

  1. Sara

    I was wondering if the watch gives your current pace or the average pace for that mile or lap.

    I have owned a couple garmins-my last one just died so I am in the market for a new one. The lap pace was one of my favorite features.

    1. Tom Leddy Post author

      It actually shows both. It shows your current pace while you’re running and the average pace for that lap at the end of each lap.

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