The diary of William Byrd II ( roughly 1709-1712) of Westover Plantation in Virginia has periodic entries of "danced my dance", exercises he did early in the morning before breakfast. He was a wealthy man, with leisure, though. How many others had enough time to exercise? An excellent time-manager like Benjamin Franklin could, but most colonial people made their living farming, and it is hard to imagine any 18th c. farmer thinking that he needed any more exercise.