build up vs warm up

build up

verb
  • To strengthen. 

  • To accumulate, to pile up, to increase in stages. 

  • To close up by building. 

  • In solitaire card games, to place a card over another card of lower value. (e.g., place 5♦ over 4♣) 

  • To erect; to construct. 

warm up

verb
  • To become warmer. 

  • To reach, or cause to reach, a normal operating temperature (of a car for example). 

  • To heat or reheat (e.g. food). 

  • To do gentle exercise, stretching etc., in order to prepare the body for more vigorous exercise. 

  • To make (an audience) enthusiastic or animated before a show 

  • To prepare for an activity by carrying out a practice or preparation routine. 

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