As far as athletes in the Ivies, since there are no athletic scholarships coaches are usually wary about athletes who appear to be using athletics to get into a school. The burden for most Ivy coaches is trying to determine whether a prospective student/athlete is serious about the sport. If they aren't, a coach can find him/herself with kids who quit the team in the first few weeks but as accepted students, have earn admission to their dream school.
I believe that most of these coaches are straight shooters, want kids to do well athletically and academically, and do not abuse the system. That was what I saw when my son was recruited to play football at Penn. He had the academic chops, but without football, would have been one of thousands who were qualified but not accepted. He spend 20 hours a week for four years working with the football team in addition to his class/study time for his major.