on the go, to be

be on the ˈgo

(informal) be busy and active: I’ve been on the go all day and I’m exhausted.She’s always on the go. I wish she would just sit down and relax sometimes.
See also: go, on

on the go, to be

To be extremely active and busy. Formerly used to mean a variety of conditions, among them intoxication and imminent catastrophe, this term acquired its present meaning in the first half of the nineteenth century. Thomas B. Aldrich used it in Prudence Palfrey (1874): “Ever since the day we said good-bye . . . I have been on the go.”
See also: on