Yeah, once HowlerKarma mentioned it, I would agree that the physical sports competitive catch up isn't something that may ever happen depending on the degree of acceleration. Unless the kiddo is very athletic, he may never be a super star compared to older kids.
In our dd's instance, she was young pre skip and really never very athletic or coordinated anyway. She wouldn't have been competitive with age peers in sports and she definitely isn't with people who are 1-2 yrs older than she as her grade peers are.