aerobics vs gymnastics

aerobics

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

gymnastics

noun
  • A sport involving the performance of sequences of movements requiring physical strength, flexibility, and kinesthetic awareness. 

  • Complex intellectual or artistic exercises or feats of physical agility. 

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