The return from underperformance to sustainable world-class level: a case study of a male cross-country skier - Talsnes, R. K.; Moxnes, E. F.; Nystad, T.; Sandbakk, Ø. (9th International Congress on Science and Skiing, March 18 - 22, 2023, Saalbach-Hinterglemm, Austria, 2023)