Playing multiple sports appears to improve performance through development of foundational transferable athletic skills.
[1][2] A large majority of elite young adult athletes, such as NCAA Division I athletes and first-round NFL draft picks, were multi-sport athletes, even if they specialized in a single sport during their professional career, and many played multiple sports even through the end of high school.
[2] Elite athletes in most sports, such as track and field, weightlifting, cycling, rowing, swimming, skiing, are less likely to have done intensive training at a young age than the near-elite athletes.
[1] NCAA Division I athletes tended to play multiple sports in high school, and only one in six specialized in a single sport before the age of 12.
Wrestlers who medaled in both Greco-Roman and freestyle wrestling in a single event: