After they had dined, Mrs. Teachum told them she thought it proper that they should use some exercise in the cooler part of the day, lest, by sitting too much, they should injure their health. – Sarah Fielding (1710–1768), “The Governess, or The Little Female Academy,”

How vain it is to sit down to write when you have not stood up to live! – Henry David Thoreau, journal, 1851 August 19th

Reginald was nearly all day at his office, and half the night at his stand-up desk in his room. – Henry Kingsley, “Reginald Hetherege,” 1874

Still, it is customary to keep pupils sitting too long at once. They ought to stand occasionally, or march around the room; and they should be required to exercise a few minutes in the open air, once an hour, at least. – American Annals of Education and Instruction, April 1832