The Strava app keeps track of the activity of people participating in sport, including their jogging routes. As a result, US military personnel that used the app while training unintentionally divulged the locations of a number of secret military bases.

The Strava app allows users to keep an eye on their performance, such as distance covered while running. They can then share this information with friends and family, who can also respond. The app also has practical functions, such as synchronising with a heart-rate monitor. This allows you to see what your heart rate was at any given moment during your run. The app has millions of users worldwide.

Heat map

In November 2017, Strava published a so-called heat map, which indicates where users have run or cycled. Joggers or cyclists can use this map to see which routes are popular in large cities. However, last weekend, the 20-year old Australian student Nathan Ruser noticed that the map also shows secret information.

On the heat map, busy cities like London, where many Strava users live, are full of jogging routes. But the problem comes when US military personnel use the app when training at secret military bases. In areas where there are few Strava users, such as war zones, such activity is even more striking. When Ruser zoomed in on Syria, ‘it sort of lit up like a Christmas tree,’ he said in an article from the The Washington Post. The 'lights' turned out to originate from military personnel using the Strava app on their secret base.

Using the heat map, Twitter users found the locations of a suspected base of the CIA, the US central intelligence agency, in Somalia, and a Patriot air defence system in Yemen, as well as others.

The Korean peninsula, clearly showing massive use of the Strava app by South Koreans,
but not by North Koreans. Source: Strava.


In a report by CNN, a spokesperson for the Pentagon stated that the US Ministry of Defence is taking this matter very seriously. It is assessing the situation to determine whether extra training is required to safeguard the security of their personnel.

Strava probably hadn't anticipated this side effect of their heat map. By the way, the problem is easily prevented, as the app has a function that allows you to block sharing information with third parties. In future, Strava aims to help people to ‘better understand’ their privacy settings, CNN stated.

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Opening image: Heat map of Amsterdam. Source: Strava

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