Tatyana Polnova (Russian: Татья́на Полнова), née Zaykova (За́йкова, born 20 April 1979) is a Russian pole vaulter.
Between 1998 and 2002 she competed for Turkey under the Turkish name Tuna Köstem.
Her personal best is 4.78 metres, achieved in September 2004 in Monaco.
This biographical article relating to Turkish athletics and track and field is a stub.
You can help Wikipedia by expanding it.This biographical article relating to Russian athletics is a stub.