aerobics vs effort

aerobics

noun
  • A form of exercise, designed to enhance one's cardiovascular fitness, normally performed to music. 

effort

noun
  • The work involved in performing an activity; exertion. 

  • An endeavor. 

  • A force acting on a body in the direction of its motion. 

verb
  • To make an effort. 

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