To try to do too much; to take on or attempt more than one is capable of doing.
burn the candle at both ends
verb
To waste something in two directions at once.
To sleep late and wake up early; not well-rested.
To work hard night and day.
How often have the words bite off more than one can chew and burn the candle at both ends occurred in a corpus of books? (source: Google Ngram Viewer )