Sidko won a bronze medal in the Individual Sprint at the 2006 Winter Olympics in Turin.

She also won a bronze in the Team sprint (with Yuliya Chepalova) at the 2005 FIS Nordic World Ski Championships in Oberstdorf and had her best individual finish of 12th in the Individual sprint in 2003.

Sidko was banned from competing at the 2010 Vancouver Olympics for breaking anti-doping rules.

She had tested positive for EPO at a race in Krasnogorsk 26 December 2009 and was subsequently banned from competing in the sport for two years.

[1] All results are sourced from the International Ski Federation (FIS).