Professional bodybuilders (L-R) Victor Martinez of the Dominican Republic, Mamdouh Elssbiay of Egypt, and Cedric McMillan and Juan Morel of U.S, pose during the Arnold Classic Brazil 2015 in Rio de Janeiro, May 30, 2015. REUTERS/Ricardo Moraes

Boxing is a sport more often associated with brute violence than with aesthetics. But photographer Howard Schatz has turned thuggish fighters into the subjects of extraordinary portraits showing the beautiful side of pugilism. The stunning pictures, collected in a new book, took six years to capture as Mr Schatz sought to investigate every aspect of the controversial sport.