She is a member of cross country ski department of AZS AWF Katowice and is coached by Aleksander Wierietielny.

Raised in the mountainous Goral village of Kasina Wielka, Southern Poland,[citation needed] Kowalczyk took up cross country skiing at the age of 10.

[5] On 27 February 2010, Kowalczyk beat Norway's Marit Bjørgen by 0.3 seconds to win the gold medal in the women's 30 km classical event in the 2010 Winter Olympics.

[citation needed] Kowalczyk won the 10 km classical race in the 2014 Winter Olympics in Sochi on a broken foot.

[6] On 22 February 2015 won bronze medal of the World Championship 2015 in team sprint with Sylwia Jaśkowiec in Falun, Sweden.

[11][12][13] At the 2005 World Championships, Kowalczyk competed but was subsequently disqualified for taking dexamethasone at the Under23 (U23) OPA (Alpine Nations) Intercontinental Cup competition in Oberstdorf, Germany back on 23 January 2005.

According to CAS, a reduced period of ineligibility ending 8 December 2005 (the day of the hearing) provided the fair and proportionate measure of sanction.

CAS criticised the FIS Doping Panel that their decision excluded any consideration of Kowalczyk's defence that she did not use the substance to enhance her sport performance.

She had submitted corresponding medical certifications to the FIS Doping Panel as proof of use in alleviating an Achilles tendon condition.

Upon Kowalczyk's prima facie showing that her use of the substance was for medical reasons, the burden of proof shifted to FIS to prove the contrary.