MOSCOW -- Margarita Mamun, the Olympic all-around rhythmic gymnastics champion, has retired at the age of 22.
Mamun's coach, Irina Viner-Usmanova, told Russia's state news agency Tass that Mamun "has finished and won't compete," adding that she "has completed her mission" in sports.
Born in Moscow to Russian and Bangladeshi parents, Mamun retires with seven world championship gold medals.
She took a sabbatical after beating fellow Russian Yana Kudryavtseva for Olympic gold in Rio de Janeiro last year but had suggested she would return for next year's world championships.
Mamun was the latest in a long line of rhythmic gymnastics champions for Russia, which has won every available Olympic gold medal since 2000.