Well, it's not the Iron Maiden or the Brazen Bull, but the treadmill of today's fitness centers does have a "tortuous history" as Dan Kopell writes at Wirecutter: Inventor William Cubitt subscribed to the “no pain, no gain” philosophy. His “Tread-Wheel,” which was described in the 1822 edition of Rules for the Government of Gaols, Houses of Correction, and Penitentiaries (published by the British Society for the Improvement of Prison Discipline and for the Reformation of Juvenile Offenders), was presented as a way for prisoners to put in an honest day’s labor.