Desidiousness. Lat. sitting too much; slothfulness, idleness, carelessness. – A New Dictionary of the English Language by Charles Richardson, 1836

I shall be compelled to buy a standing-desk, which will cost me from two to three dollars, as the older students advise me to have one as necessary to my health. – James Stokes Dickerson, letter to brother, 1842 October 13th

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

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