The Post reported that by zooming in on war zones and deserts in countries like Iraq and Syria, locations and outlines of known USA military bases could be seen - along with other unknown and potentially sensitive sites.
The company's review of 2017 showed all routes taken by its users across the world.
Lewis writes, "there are a number of avid Strava users who work there, causally jogging right by the parking lot where the missile launchers are parked".
This is also true of British military bases.
Strava says the onus is on the public to mark their own data as private, or to create their own privacy zones to ensure sensitive data doesn't go public. "Recent data releases emphasize the need for situational awareness when members of the military share personal information", said Pentagon spokeswoman Harris.
The map shows a great deal of activity in the U.S. and Europe, but in war zones and deserts in countries such as Iraq and Syria the heat map becomes nearly entirely dark - except for scattered evidence of activity.
The Post added that other journalists on Twitter were also weighing in on what they identified to be US military bases.
Online fitness tracker Strava has published a "heatmap" showing the paths its users log as they run or cycle.
Other easily identifiable bases include those used by the U.S. in Syria and Iraq, a UK RAF base in the Falklands, and one used by French forces in Niger.
The US military is examining the heatmap, a spokesman said.
The map of Iraq is largely dark, indicating limited use of the Strava app, but a series of well-known military bases where American and allied forces have been deployed as part of their war against the Islamic State of Iraq and the Levant (ISIL) are highlighted in detail.
The location of military bases is generally known by other factors, including local knowledge of an area and pre-existing satellite imaging tools such as Google Earth.
In response to the reports, Strava said that the map excludes locations and activities users designate as private and that it's "committed to helping people better understand" its privacy rules, CNN reports.