Ida Lien made her international debut at the 2017 Junior European Championships in Nové Město na Moravě, Czech Republic.

At the 2020 European Championships, Lien won a bronze medal in the mixed relay alongside Åsne Skrede, Sivert Bakken, and Aleksander Fjeld Andersen.

Running third in the women’s relay, she kept the team in the lead, ultimately securing the gold medal alongside Ingrid Landmark Tandrevold, Tiril Eckhoff, and Marte Olsbu Røiseland.

Throughout the season, Lien consistently earned World Cup points and, in March 2021, achieved her first Top-10 individual result with a ninth-place finish in the Östersund sprint.

In the 2021/22 season, Lien's performances peaked in December, highlighted by a fourth-place finish in the Hochfilzen sprint, where she narrowly missed her first podium by just over two seconds.

After a series of average results, she impressed in Antholz, bringing the Norwegian women’s relay team from a significant deficit to the lead with flawless standing shooting, contributing to their eventual victory.

At the World Championships in Oberhof, her best result was 17th place in the individual event, while the relay team finished sixth after a total of four penalty loops by Lien and Ingrid Landmark Tandrevold.

[6][7] Despite a significant improvement in her back pain during the summer period, she, like the other members of the elite team, arrives in a relative poor form for the selection races in Sjusjøen in mid-November.