Strava heatmap of Portlaoise Prison.
Data from Strava fitness tracker which has caused security concerns over the location US military bases, appears to reveal that someone is monitoring their fitness inside the walls of Portlaoise Prison
The online fitness tracker's "heatmap" show the paths its users log as they run or cycle.
A satellite map for Portlaoise appears to show a lap of regular activity in one of the new wings to the left of the old main entrance to the prison.
There do not appear to be any heatmaps showing in other buildings or for the inside of the adjoining Midlands Prison. The entrances and exits to the Midlands Prison are bright.
The tracker has received global attention as it appears to have revealed foreign military bases in countries including Syria and Afghanistan .
Strava's app uses a phone's GPS to track a subscriber's exercise. Data collected, as well as that from fitness devices such as Fitbit and Jawbone, is used to enable people to check and compare their performances with others.
It claims to have 27 million users. The heatmap is a visual image of all their activity.
The latest heatmap has been built from one billion activities, covering 27 billion km of runs or swims around the world.
The data shows the activities between 2015 and September 2017.