delayed-onset muscle soreness vs rigour

delayed-onset muscle soreness

noun
  • The pain and stiffness felt in muscles several hours to days after unaccustomed or strenuous exercise. 

rigour

noun
  • A trembling or shivering response. 

  • Character of being unyielding or inflexible. 

  • Higher level of difficulty. 

  • Harshness, as of climate. 

  • Shrewd questioning. 

  • Severity or strictness. 

How often have the words delayed-onset muscle soreness and rigour occurred in a corpus of books? (source: Google Ngram Viewer )