GPS accuracy and running watches: Improving how we track our health and fitness
If you’re a runner, you might be used to the squiggly patterns that you trace on your GPS app: a chaotic maze of streets and paths. In fact, GPS route tracking has now even become an art form in itself: for example, this London jogger intentionally plans his routes to create animal illustrations while running and Strava artwork has grown in popularity.
But you might also be familiar with the frustration of your GPS device misreporting your distance or time, or your tracked routes suggesting you’ve run through building walls or magically walked over rivers. Imagine that you’ve meticulously planned your route to cover exactly 10 miles, and you’re confident you can finish it in record time. But in reality, when you finish your run, your smartwatch only reports about 9.3 miles. The joy of smashing your personal best evaporates instantly, replaced by a sinking disappointment.
Inaccurate tracking in GPS devices is unfortunately common, with most running watches susceptible to errors in areas without a clear view of the sky, such as dense urban environments and forests. A quick Google search will pull up hundreds of articles reporting on which brand of fitness wearable is the most accurate: from Garmin and Fitbit to Apple and Samsung. As brands battle among themselves in the race to offer accurate GPS tracking, it’s worth examining what causes these inaccuracies.
Our movement on the Earth is tracked by satellites in space. The more technical term for GPS is GNSS or Global Navigation Satellite System, which refers to the satellites that can help pinpoint our location on the ground. The term "GPS" specifically refers to the American GNSS system, but it is often used interchangeably with GNSS. In addition to GPS, there are other major GNSS networks, including Europe’s Galileo, China’s BeiDou, and Russia’s GLONASS, among others.
Why is GPS tracking so important for monitoring our health?
For fitness enthusiasts, especially runners and athletes, tracking distance, routes and time is essential for improving performance and achieving personal or competitive goals. From beginners aiming to run their first 5K to elite marathoners chasing world records, activity tracking plays a crucial role in understanding progress. The competitive nature of sports also demands high accuracy in tracking stats like distance, time and pace. But elite runners participating in marathons frequently experience discrepancies in the data reported by their wearables and running apps, adding to the confusion.
Tracking fitness performance is more than just a way to satisfy curiosity. It plays a key role in goal-setting, optimising training and preventing injuries. Some of the most critical reasons athletes rely on tracking include:
Goal-setting and improvement: Setting clear and measurable goals is one of the core principles of sports training. Whether you’re a casual runner looking to increase your weekly mileage or preparing for the Olympics, you need to be able to track your data accurately so you can achieve your targets and move to the next level.
Performance evaluation: By recording real-time data such as pace, distance, and heart rate, athletes can analyse their performance in each workout or race. They can see how their current metrics compare to previous efforts and determine whether they are progressing or regressing. Accurate data also helps in the creation of personalised training plans for athletes.
Injury prevention: Consistently tracking an athlete's movements can help identify patterns that may lead to overuse injuries or excessive fatigue. For example, a significant drop in pace during a run might indicate overtraining, allowing athletes to adjust their load before injury strikes.
GPS in action: Benefits for runners
Over the past few decades, the adoption of GPS technology in wearable devices like running watches, smartwatches, and fitness trackers has transformed how athletes track and measure their performance. Today, athletes can easily gather data on pace, distance, elevation, and more.
Route tracking: The obvious benefit of GPS tracking is route and distance tracking. GPS devices make it easy for athletes to map out their runs.
Real-time performance feedback: GPS devices provide instant feedback, so that athletes can adjust their pace, effort or change their route mid-workout. This real-time data helps with pacing strategies or in setting clearer or more realistic goals.
Group training: While GPS tracking devices are often thought of as monitoring individual athlete performance, it is also used for group training. In Ethiopia, for example, GPS watches can play an important role in group dynamics among runners. These devices help track collective progress, and authority figures (like coaches) use them to guide and control group training.
Safety: GPS helps runners navigate unfamiliar territory, something which is especially important in trail running. Athletes can refer to a map before their run and carefully plan their route in diverse terrain.
However, while GPS/GNSS provides a wealth of useful information, it comes with its own set of limitations, especially in challenging environments.
GPS accuracy: Common challenges faced by runners and fitness enthusiasts
Enhancing GPS accuracy in running watches and fitness devices is of utmost importance for athletes, whose performance can be highly sensitive to the smallest discrepancies in tracking data. There are 3 main reasons GPS inaccuracies occur:
Signal reflection in urban areas: One of the most significant issues with GPS tracking is accuracy in areas with tall buildings, such as London’s Canary Wharf. GPS signals can reflect off the surfaces of high-rise buildings, a phenomenon known as multipath.
Weak signals in forests and woodland: In areas with dense foliage, GPS signals are weakened. For trail runners, thick tree cover can weaken satellite signals, not just causing errors in tracking data but also making it harder for the runner to navigate a route, causing delays.
Concealed antennas: Aesthetics and design impact the look and feel of wearables, which play a key role in the consumer’s purchase decision. GPS, which relies on an antenna to receive the signal, can be impacted if the antenna is concealed – which is common in wearables design today.
London Marathon 2024 in Canary Wharf, London
How to improve GPS accuracy in running watches
As GPS/GNSS technology becomes more deeply integrated into athletic performance tracking, the demand for technology that mitigates the challenges mentioned above is increasing. Runners and athletes depend on precise data to improve performance, and even small errors in tracking can lead to confusion, frustration, and suboptimal training results.
There are several ways to improve GPS accuracy in wearables. Dual-band GPS, as seen in devices like the Apple Watch Ultra 2 and some Garmin models, uses two frequencies for greater precision. Smartwatches such as the Garmin Fenix 7 leverage multiple satellite systems (GPS, GLONASS, Galileo, BeiDou, and QZSS) simultaneously for better positioning. High-end wearables often come with superior antennas to reduce errors – however this comes at a cost.
FocalPoint’s positioning software enhances GPS accuracy at the chipset level, demonstrating up to ten times improvement in positioning accuracy. This means that wearable manufacturers can offer accurate tracking along with a superior user experience. For athletes, this means they can rely on their device to provide accurate data so that they can confidently track their progress and measure success.