[4] Gabriela Gajanová gained her first international experience in 2015, when she was eliminated in the first round of the 400-meter run at the 2015 European Youth Summer Olympic Festival in Tbilisi with a time of 57.91, and was also unable to qualify for the final with the Slovakian 4 x 100 meter relay team with a time of 49.28.

[2] In 2023, she reached the semifinals of the 800 metres at the European Indoor Championships in Istanbul and was eliminated there with a new national record of 2:01.70 min.

[2] At the World Athletics Continental Tour in Bellinzona, Gajanová ran a time of 1:58.78 in the 800 metres, surpassing the qualification threshold for 2024 Summer Olympics.

After not being among the top in the heats but still managing to advance, she strong on the run and was close to sprinting down the pre-favourite Keely Hodgkinson.

[7][8] At the 2024 Summer Olympics in Paris, Gajanová beat the Slovak record in 800m, held since 1987 by Gabriela Sedláková, with the time 1:58.22.