运动家 covers two senses depending on context. In sports it means 'athlete' (more common in Taiwan; mainland speakers usually say 运动员 yùndòngyuán). With a cause prefix like 环保 (environmental) or 民权 (civil rights), it means 'activist'.
register
运动家精神 (yùndòngjiā jīngshén) — 'sportsmanship' — is the most common collocation. It carries the same connotation of fair play and grace under pressure as the English term.
