In August 1999, Tchachina began training at the Olympic Preparatory School under the guidance of Irina Viner, and around the same time she won the World Championships in Osaka, Japan. In 2001, she won the gold in the hoop and silver in the individual all-around, ball, clubs and rope at the 2001 World Rhythmic Gymnastics Championships in Madrid, Spain, but Tchachina and her teammate Alina Kabaeva tested positive for a banned diuretic and were stripped of their medals. Irina Viner, the Russian head coach, who also served as the Vice President of the FIG Rhythmic Gymnastics Technical Committee at the time, said her gymnasts had been taking a food supplement called "Hyper" containing mild diuretics, which, according to Viner, the gymnasts were taking for pre-menstrual syndrome. When the supply ran out shortly before the Goodwill Games, the team physiotherapist restocked at a local pharmacy. According to Viner, the supplement sold there was fake and contained furosemide. The commission requested the Goodwill Games organizing committee nullify Kabaeva and Tchachina's results.