Author(s): MOTTET, J., SCHORDERET, F., BOURDILLON, N., MILLET, G., Institution: UNIVERSITY OF LAUSANNE, Country: SWITZERLAND, Abstract-ID: 577

INTRODUCTION:
Ski mountaineering (SkiMo) sprint is a recently introduced Olympic discipline. The competition consists of a qualification round followed by knockout heats lasting ~2-3 minutes, with ~20-25 minutes of rest between. Each heat includes two uphill (U) skiing sections with skins, one foot part section, one downhill (D) skiing section, and three transition zones (T). This study aimed to identify performance determinants of SkiMo sprint during the Milan-Cortina Olympic Test Event by (1) analyzing section-specific contributions to overall sprint time (SPT), and (2) examining associations between the best uphill time excluding transitions (TSF) and laboratory-derived physiological parameters.
METHODS:
SPT and seven split times were analyzed during quarter-final for 36 qualified athletes. Section contributions to SPT variability were assessed using the covariance-to-variance ratio. Analyses were conducted separately for the top 18 seeded athletes (QF A) and those ranked 19-36 (QF B). Correlations between split times and SPT were computed across the entire sample.
A subgroup of Swiss male SkiMo sprinters (n = 9; Tier 4-5) underwent laboratory testing. Aerobic and anaerobic capacities were assessed via an incremental test (GXT) and a time-to-exhaustion test at 120% of GXT maximum speed. Post-GXT passive blood lactate recovery was evaluated for 20 minutes (dBLarec). Associations between these variables and TSF were examined using correlation analyses and stepwise multiple regression (SMR).
RESULTS:
U time accounted for the largest proportion of SPT variability (81.5%) and was strongly correlated with SPT (r = 0.89, P < 0.0001), particularly during the first section of the race (r = 0.91, P < 0.0001). The first T showed a moderate association with SPT (r = 0.62, P < 0.05), whereas no significant associations were observed for the remaining U, T, or D sections. For QF A, T time contributed to a larger proportion of SPT variability than for QF B (46.8% vs. 18.4%).
In Swiss athletes, TSF correlated with GXT maximal vertical velocity (r = -0.73, P < 0.05), and maximal oxygen uptake (VO2max) (ml/kg/min) (r = -0.73, P < 0.05) and SMR identified VO2max and dBLarec as the best TSF predictors (R2 = 0.82, P < 0.01).
CONCLUSION:
These findings indicate that sprint performance in elite SkiMo is largely determined by aerobic power supporting fast uphill sections, together with rapid race initiation. This aligns with determinants reported in cross-country sprint skiing, which shares a closely comparable competition format. Interestingly, dBLarec was also associated with sprint performance, suggesting a potential role of lactate shuttle capacity on fatigue resistance during a supramaximal SkiMo sprint. Finally, the relatively greater contribution of T to sprint performance among world-class athletes highlights that SkiMo sprint isn’t only about physiological capacity but also about highly efficient T under maximal effort.