personal trainer vs trainer

personal trainer

noun
  • Someone employed to help another with their fitness, especially by means of a personalised diet program and exercise regime. 

trainer

noun
  • A person who trains another; a coach. 

  • A person responsible for treating injuries sustained by players during matches; a physiotherapist. 

  • A patch for a video game that applies cheats. 

  • A running shoe or sneaker. 

  • A piece of indoor equipment allowing a bicycle to be ridden while stationary. 

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