overextend vs work oneself into the ground

overextend

verb
  • To push a pawn too far, so that it becomes vulnerable to the opponent's attacks. 

  • To expand or extend to an excessive degree, especially to do so beyond a safe limit. 

  • To apply (a term) to too many referents, by overextension. 

work oneself into the ground

How often have the words overextend and work oneself into the ground occurred in a corpus of books? (source: Google Ngram Viewer )