arduous vs refreshing

arduous

adj
  • Needing or using up much energy; testing powers of endurance. 

  • Difficult or exhausting to traverse. 

refreshing

adj
  • That refreshes someone; pleasantly fresh and different; granting vitality and energy. 

  • Serving to refresh, particularly with respect to an electronic screen, or a browser window or similar computer application. 

noun
  • The action of refresh; refreshment given or received. 

  • That which gives refreshment. 

How often have the words arduous and refreshing occurred in a corpus of books? (source: Google Ngram Viewer )