Reusser grew up in a farming family in the Emmental and came to cycling late. She played the violin until she was sixteen, then ran until ankle injuries pushed her towards the bike. She rode the cycling legs of mixed relay triathlons as an amateur while studying medicine. In 2017, in her final year of medical study, she entered the Swiss national championships and won the time trial, and was picked for the European and World Championships that season.
She took a place at the UCI's World Cycling Centre in Aigle in 2019 and gave up combining racing with hospital work as an assistant surgeon. World time trial medals followed: second to Anna van der Breggen at Imola in 2020, second to Ellen van Dijk at Bruges in 2021, third behind van Dijk and Grace Brown at Wollongong in 2022. At the Tokyo Olympics she took silver behind Annemiek van Vleuten.
She won the European time trial at Trento in 2021, at Munich in 2022 and at Drenthe in 2023. In 2024 she took Setmana Ciclista Valenciana in February, crashed at the Tour of Flanders at the end of March, and was later diagnosed with post-COVID syndrome in the form of ME/CFS. She missed the Paris Olympics and the World Championships in Zurich, on Swiss roads.
She joined Movistar for 2025. In May she won Vuelta a Burgos Feminas, taking the mountain stage by forty seconds and then the closing time trial. In June she won the Tour de Suisse Women with two stage wins, ahead of Demi Vollering. At the Giro d'Italia Women in July she won the opening time trial and led the race, then held second overall behind Elisa Longo Borghini while ill in the final days.
Her Tour de France Femmes lasted a stage. She crashed early on the opening day and abandoned, still carrying the illness from the Giro. She came back at the World Championships in Kigali in September and won the time trial ahead of Anna van der Breggen and Demi Vollering, her first elite world title, then won the European time trial again at Guilherand-Granges in October.









