In today’s technological age, working out has become easier than ever. Trying to balance your macros? There’s an app for that! Want to know how many calories that bagel is? There’s an app for that! Interested in knowing how far you walk each day? You bet there’s an app for that.

As wellness gurus and the masses alike take advantage of their newfound access to “health,” however, many neglect to research the technologies they’re using. How exactly does Fitbit knows how many steps you take per day? The answer is simple— the same way that apps like Snapchat present you with geofilters and show your location to your friends.

The world is becoming more interconnected, for better or for worse. Unfortunately, the convenience that comes with the most frequently-used apps are often connected to security concerns that go unnoticed. Although many of us don’t mind the visibility lended by fitness technology, the issue has been highlighted recently as the Strava fitness app released user information that could potentially show the locations of US army bases abroad.

Strava is tailored to avid runners and cyclers, but has the potential to be used by anyone interested in noting their daily exercise. Last Monday, the New York Times published a report in regards to a global heatmap released by Strava that gave a visual representation of user activity across the globe. From a marketing standpoint, the heatmap was a great way for Strava to pinpoint demographics to cater to and document its progress to the market. However, the concentration of activity was notably diffused as the map moved outwards from the Western hemisphere, leaving data from Asia and the Middle East especially visible.

One especially visible area, as noted by Fox News, was the area around Kandahar Airfield in Southern Afghanistan. The visibility of Kandahar was not an anomaly— a greater pattern was first noted by Institute for United Conflict Analysts employee Nathan Ruser on Twitter. As Ruser pointed out on the 27th, it wasn’t just the United States’ security that was compromised; the heatmap also showed Russian operations in Khmeimim and Turkish patrol of Manbij.

Both Strava and the Department of Defense have since issued reports, illustrating the gravity of the situation. Although Strava does give users the option to refrain from sharing their location, a representative of the app has stated that they “are committed to helping people better understand [their] settings to give them control over what they share,” in a statement to Fox.