Claim: Mike Tyson was in the heaviest category of a sport.

A weight class is a measurement weight range for boxers . The lower limit of a weight class is equal to the upper weight limit of the class below it . The top class , with no upper limit , is called heavyweight in professional boxing and super heavyweight in amateur boxing . A boxing match is usually scheduled for a fixed weight class , and each boxer 's weight must not exceed the upper limit . Although professional boxers may fight above their weight class , an amateur boxer 's weight must not fall below the lower limit . A nonstandard weight limit is called a catch weight .