So did he run from station to station above ground following the tracks, or is it too difficult to follow the tracks (buildings, obstacles, etc)?
Therefore, I ran from station to station - worked out the routes before each run and ran with my iPhone and Google Maps and ran to each station on each Underground line. The distance is greatly lengthened because I couldn't run on the tracks but I still visited every station - some as many as 6 times as they appear on 6 different lines.
I had a picture outside of every single one and then went on my way to the next station. I ran over moterways, over footbridges, canals, fields, commuter packed pavements, marsh land, cobbled streets and got lost an awful lot.
Lol...brilliant, and truly inspiring.
EDIT: To illustrate this.
London: https://en.wikipedia.org/wiki/File:Why_London_Underground_is...
Stockholm: https://en.wikipedia.org/wiki/File:Swe_subway_switch_2005042...