break a sweat vs sweat out

break a sweat

verb
  • To start sweating. 

  • To put effort into something. 

sweat out

verb
  • To sweat; to secrete sweat because of heat, nerves etc. 

  • To endure or go through (an ordeal). 

  • To accomplish or achieve, usually through endurance or effort. 

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