Complex sentence: After the retirement of Kabaeva and Tchachina, Olga would become one of Russia's top gymnasts scoring a number of medals in the World Cup series in 2007 and 2008.
Split into simpler sentences: After the retirements of Russian gymnasts Kabaeva and Tchachina, Olga became one of Russia's top gymnasts. Olga continued her success scoring a number of medals in the World Cup series in 2007 and 2008.