As an alumnae interviewer for _my_ Ivy alma mater,
@Grace T. has this pretty spot on. I've interviewed hundreds of kids and while almost none of them get in, the ones that do tend to be very passionate about one thing rather than "well rounded". You can tell right away if they're taking tap dancing because they freakin' love tap dancing or because they (or their parents) think it'll look good on their resume. If I were to interview a kid who spent most of their after-school time playing sports and most of the interview talking about sports, but weren't planning to play sports in college, I would wonder what they would do when they got to school.
If the story is: I love sports, but it turns out I'm not that great so I switched to... something else. That can work. Or even, I love soccer, but I would sit on the bench at a D1 school, so I dialed back (moved to EA or ECRL, say) so I can focus on academics and play D3 or maybe walk on D1 somewhere, that would work too, as long as they have something else they love. By jr. year, most kids should have a realistic idea about their college prospects and adjust accordingly.