Although a member of the Russian national team since 1999, Yefremova rarely qualified for the top competitions, and had to content herself with successes at second-tier European Championships. After missing the 2002 Olympics, she switched to competing for Belarus. She then competed a full season in the World Cup events, winning her first race with the Belarussian relay team. But a training dispute led Yefremova to switch countries once again, now turning to Ukraine. For her new country, she also was a regular World Cup and World Championship competitor, but without major successes. Early in the 2005/2006, she suddenly won her first individual World Cup medal, placing third in the Pokljuka sprint race. She was able to repeat this placing at the Torino Olympics, although Yefremova was lucky to benefit from a weather change during competition