I invented a series of exercises… which I practice while I lie in bed in the morning. These movements were so designed as to exercise every part of the body, and I speedily found that equal benefit resulted as though they were practiced in an elaborate gymnasium.
The text is from Exercising in Bed: The Simplest and Most Effective System of Exercise Ever Devised, by Sanford Bennett (1907). Click here to read it online, or download it free, from the Internet Archive.
artwork by Joanne Stanbridge 2014