Background The ‘Norseman Xtreme Triathlon’, held annually in Norway, is considered one of the world’s most challenging triathlons, surpassing the traditional IRONMAN®-distance in terms of difficulty. This narrative review aims to summarize the current scientific evidence to support athletes and coaches in preparation for this event. Methods We conducted a narrative review to summarize the current scientific literature on the ‘Norseman Xtreme Triathlon’. A structured search was conducted in two major databases—PubMed and Scopus—using free-text terms related to ‘Norseman Xtreme Triathlon’. The search included articles published up to the end of November 2025, without language restrictions. After removing duplicates and unrelated articles based on title and abstract screening, 16 relevant publications were included for analysis. Results Over the years, the number of female and male finishers increased, the men-to-women ratio decreased, and both split and overall race times decreased. Most athletes competing in the ‘Norseman Xtreme Triathlon’ came from Norway, and Norwegian athletes achieved the most podiums. The race affects different organ systems and biomarkers, with increased values of WBC, CK, NT-proBNP, CRP and AST returning to pre-race levels within hours or days. Due to the cold environment, athletes appeared to be at risk of developing hypothermia and swimming-induced pulmonary edema (SIPE) during swimming and both exercise-induced bronchoconstriction (EIB) and exercise-induced arterial hypoxemia (EIAH) after the race. Conclusions Particular care is needed in preparing for the cold water and general cold environment during cycling and running. The specific nutritional demands, the aspects of pre-race preparation (e.g. training, experience), post-race recovery trajectories, hormonal profiles, or psychological responses of the ‘Norseman Xtreme Triathlon’ remain underexplored and represent an important area for future research.