Maybe this is relevant, maybe not.
My high school's big rival when I was growing up typically had better athletes because they recruited from all over the city for sports, while we just went with whoever was admitted on academic grounds.
While I was in HS, they recruited Sean Taylor to play football. I played against him, and he was clearly a man amongst boys. He crushed us and was physically clearly superior to everyone else on the field with speed and size and talent. They won the state championship, he went on to play for UM and would have been an NFL hall of famer if not for his untimely murder.
That same HS also recruited a super-talented runner for their cross country team a few years later, Andrew Talansky. Much skinnier and with great endurance, he won a ton of cross country races and then took up cycling in the offseason. He ended up being recruited by a college cycling team, won the national championship the next year, and has now made a name for himself at the TdF as a pro tour rider.
Point is- Andrew ran from a young age and knew he wanted to participate in endurance sports. He didn't try out for his school's football team and get cut, he specialized in his preferred discipline long before he got recruited. Same story with Sean. He played peewee football and excelled, and he focused on that for the rest of his life. Both of them had genetic predispositions to excel at their chosen activities. Sean would maybe have been a decent amateur sprinter on a bike if he'd taken that up from a young age, but he would never have been able to make it to the professional level, even if he'd worked just as hard as Andrew.