The first exercise guru (and part-time literary critic)

'Cheyne championed the "chamber horse", a chair sporting an elevated seat on what resembled an accordion bellows. Inside was a large spring, and by gripping the chair's arms you could bounce up and down in a simulation of horse-riding. In short, Cheyne was promoting one of the very first examples of home gym equipment.

[...]

Chamber horses became de rigueur. Even the dour Methodist theologian John Wesley spent time each day bouncing up and down on one. Cheyne recommended to Samuel Richardson that he compose his novel "Pamela" by dictating it while bouncing on a chamber horse, and then helpfully suggested that Pamela would also be improved by adding house fires and plenty of broken limbs into the plot'

- New Scientist, 7 October 2006, on George Cheyne (1671-1742), early essayist on dieting.