RichThesaurus
bite off more than one can chew
vs
work one's balls off
bite off more than one can chew
verb
To try to do too much; to take on or attempt more than one is capable of doing.
work one's balls off
How often have the words
bite off more than one can chew
and
work one's balls off
occurred in a corpus of books?
(source:
Google Ngram Viewer
)