380m on foot, 2 ticket barriers and 75 steps to climb.
For those of you who regularly take the circle line, the thought of just getting off and walking to the next station will have crossed your mind on many a morning commute.
Dressed in running gear with a camera strapped to his head, and a friend to video the tube ride, James Heptonstall, hopped on the circle line at Blackfriars, hopped off at Mansion House and ran to Cannon Street.
Did he make it back on the same tube? Here's how he got on ...