Depending on your abilities and the sport, it could range from a slight loosening to a pretty considerable one.
However, just being a top level soccer (or whatever) player isn’t helpful. It is only helpful if you are being recruited by a coach for one of her limited slots. If you aren’t, then you have to go through the same process as everyone else, with the same odds of admission.
There will be some absolute floor that the coach can’t drop below. She also will have an academic index average that she needs to hit as an average for all recruits for the year. That average is primarily based on test scores, with GPA making a smaller contribution. Depending on that sport, it may be a number pretty close to the average for the university as a whole, or it could be quite a bit lower. The athletic department has to keep the total athlete AI within one standard deviation of the AI of the student body as a whole. As far as which teams bring the score up and which are allowed to go lower, that is up to the athletic director. Generally speaking, more blue collar sports and revenue sports get to have lower targets.
Having said that, even for a top recruit for a high priority sport, the academic cut-offs are pretty high. If you share your sport then we can give you much more helpful info. More than likely there are several people on the board with recent Ivy League recruiting experience in your sport.