33 Year old wins silver.
The "they are young and therefore have an advantage" arguement is rather demolished by the gymnast Oksana Chusovitina
At 33 years old she won silver on the vault at the Beijing olympics and has competed at the olympics since Barcelona 1992 and is considering London 2012.
If you have the mental strength and commitment to continue you often can. Most of the children quit around age 21 to do other stuff however.