Amy Chow: started at age 3
Shannon Miller: at age 5
Miller was the balance beam gold medalist in the 1996 Atlanta Games.
Nadia Comaneci: at age 6
Comaneci was the all-around gold medalist in the 1976 Montreal Games. She won four gold medals in individual events at Montreal and in the 1980 Moscow Games.
Dominique Dawes: at age 6
Kim Zmeskal: at age 6
Mary Lou Retton: at age 7
Retton was the all-around gold medalist in the 1984 Los Angeles Games.
Cathy Rigby: at age 11
Sources: World Features Syndicate; The Complete Book of the Summer Olympics.