Be on the go
Definition 1 of 3
Pro Tip 1/3Character Implication
Using 'on the go' can suggest a person is energetic and possibly overwhelmed. 
With three kids, Lena is constantly on the go.
Pro Tip 2/3Non-Literal Use
Sometimes 'on the go' is used to describe being active without implying specific tasks. 
Even on vacation, she likes to be on the go.
Pro Tip 3/3Social Implications
It can imply admiration or concern for someone's packed schedule. 
I admire how you're always on the go; make sure to rest too.