Peak Age and Relative Performance Progression in International Cross-Country Skiers.

PURPOSE To quantify peak age and relative performance progression toward peak age in cross-country skiing according to event type, sex, and athlete performance level. METHODS International Ski Federation (FIS) points (performance expressed relative to the best athlete) of athletes born between 1981 and 1991, competing in junior world championships or finishing top 30 in world championships or Olympics, were downloaded from the FIS website. Individual performance trends were derived by fitting a quadratic curve to each athletes FIS point and age data. RESULTS Peak age was 26.2 (2.3) years in distance and 26.0 (1.7) years in sprint events. The sex difference in peak age in sprint events was ∼0.8 years (small, P = .001), while there was no significant sex difference in peak age in distance events (P = .668). Top performers displayed higher peak ages than other athletes in distance (mean difference, ±95% confidence limits = 1.6 y, ±0.6 y, moderate, P < .001) and sprint events (1.0, ±0.6 y, moderate, P < .001). FIS point improvement over the 5 years preceding peak age did not differ between event types (P = .325), while men improved more than women in both events (8.8, ±5.4%, small, P = .002 and 7.5, ±6.4%, small, P = .002). Performance level had a large effect on improvement in FIS points in both events (P < .001). CONCLUSION This study provides novel insights on peak age and relative performance progression among world-class cross-country skiers and can assist practitioners, sport institutions, and federations with goal setting and evaluating strategies for achieving success.