Should You Trust the Accuracy of the GPS Watch

Until recently, the GPS navigation devices on the market were always large and bulky and inappropriate to carry with you on a daily run or hike. But with the advance of technology, these devices have become smaller and more reliable and very easy to carry with you.

Today, many manufacturers produce GPS sports watches that have many desirable features above the basic GPS tracking feature. No matter how much we enjoy the other features these devices have to offer, the most important feature is still GPS tracking and navigation that the device provides.

Wearing a GPS watch

Since most professional long-distance runners, triathlon athletes and many others use these devices, we should be safe to use them in our everyday training runs, right? But we cannot help but wonder what is the accuracy of the GPS watch? Does it always show the exact distance passed or is there some extra mileage shown?

The GPS watch is not an essential feature for the runner, but it does offer several interesting information. The GPS watch records data on distance and speed, some even measure heart rate and calculate calories burned and much more.

The information on the passed distance and the speed of the run always help the runner improve their performance, making sure that they stay in top shape, not lagging but not overdoing it. This information is shown via the GPS function in the watch.

The GPS watch (and any other GPS device) uses information from the GPS satellite system via appropriate sensors, receiving continuous signals that are translated into location coordinates at different points of time. The watch then calculates the distance and speed traveled by the runner.

Accuracy of a GPS watch

The GPS satellite system is a network of 24 satellites around the Earth. In order to get adequate information, the GPS watch needs to be connected to at least three satellites.

The GPS satellite system is run by the US Air Force; it is their claim that the precision and accuracy of the GPS location is up to 3.5 meters or about 11 feet, which is pretty accurate.

However, many of the GPS sports watch manufactures cannot support this and the accuracy of their devices is somewhere in the vicinity of 15 meters or just below 50 feet. This accuracy is still pretty good, seeing that the GPS signal has to travel from the satellites orbiting height at 12,540 miles above Earth.

How accurate do GPS sports watches need to be?

We have seen the average accuracy of GPS sports watch. But do we really need such accuracy in our everyday training cycles? Actually, no. There is no perfectly accurate GPS watch, and this is absolutely fine.

Most of the reasonably and high-priced GPS watches have provided pretty consistent measurements of distance and speed. This information is most likely to be enough for obtaining the proper statistics on your training sessions and calculating and tracking your general progress.

Interference with GPS watches

The GPS enabled devices, including the GPS sports watches, use low energy radio waves to communicate with the GPS satellite network. This means that there will be different interferences in different locations.

The same GPS sports watch will not have the same accuracy in a crowded city environment and in an open field. In a crowded city environment, there are many sources of different frequencies that interfere with the satellite signal, and there are also tall buildings that serve as obstacles and do not enable direct line of connection to the satellite.

Also, the terrain and weather conditions can have a strong influence on the GPS watch, providing interference with the satellite signal.

Other factors that influence the GPS watch accuracy

The signal from the GPS satellites travels with almost the speed of light, the almost being the important word, the GPS receiver in the watch gets a signal, and the next signal is updated just a few seconds later.

During your run, you will pass a certain distance over the course of this time between signals. And since the satellite isn’t able to “see” your actions in between the few seconds delay like a sharp bend that adds or reduces the overall passed distance, the overall accuracy of the watch is not that accurate.

As noted before, this is also influenced by the environmental factors like buildings or weather conditions. A standard marathon length is 26.2 miles, and the marathon runners that use different brands of GPS watches report slightly different lengths varying from 26.2 to 26.9 miles.

This is a confirmation of the accuracy of the GPS watch, which is actually not bad, knowing that the standard marathon is almost always run in a crowded city environment with many obstacles for the GPS signal.

Other alternative options to GPS watch

The runners do not need to depend on a GPS sports watch during their run, and can instead use a GPS app on their smartphone. There are also dedicated sports apps that facilitate the tracking of the running progress, like the distance and speed, allowing the use of the smartphone as a GPS device.

The most popular function of the GPS sports watch, the heart rate monitoring can’t be used directly via the smartphone and this is done by using an external monitor or a chest strap connected to the smartphone.

To finish up

A GPS sports watch is a nice gadget to have and use. Offering a range of functions, enabling tracking and statistics on various aspects of the training routine, you will not be wrong to treat yourself with one.

The GPS sports watches get improved update speed and functions every day, but there are, of course, limitations to every technology. And this is not a confirmation on their precision, as they can always inadvertently add a few extra yards on your final score.

You should select a GPS sports watch that will fit your needs and available budget, and be assured that you can trust the results it provides during your daily training routine.