noun
heavyweight player; heavyweight athlete
Used in sports contexts to refer to a competitor in a heavyweight division, such as boxing, wrestling, or weightlifting.
彼は重量選手としてオリンピックに出場した。
He competed in the Olympics as a heavyweight athlete.
重量級 refers to the heavyweight class or division itself, while 重量選手 refers to a person who competes in that class.
Compound of 重量 (weight) + 選手 (player, athlete).