Lower-Limb Strength in Alpine Skiing: Are Maximal, Explosive or Endurance Capacities More Important for Performance?

Maximal force production capacities are essential for skiing performance. Despite the evidence of dynamic demands and fatigue during racing, the relative importance of maximal, explosive, and endurance strength capacities remains unclear. The aim of this study was to investigate the specific association between lower-limb isometric maximal, rate of force development, and critical force to event-specific skiing performance. Fifty-nine skiers were recruited from national (NAT, n = 24) and regional (REG, n = 35) levels. Skiers had their isometric maximal force (Fmax), maximal rate of force development (RFDmax), and critical force (CF) assessed on a leg press ergometer. NAT skiing performance in each skiing event (Slalom, Giant-Slalom, Super-G, Downhill) was defined as FIS points. For REG skiers, performance was represented in their total time to complete a controlled giant-slalom race. Force production capacities were compared between NAT and REG using independent t-tests, with the contribution of each force production capacity to performance (event-specific FIS points for NAT and experimental race time for REG) assessed via stepwise linear regression models. The alpha value was set at 0.05. NAT presented higher Fmax (Hedges'g = 1.21, p < 0.001), RFDmax (g = 1.01, p < 0.001), and CF (g = 1.88, p < 0.001) than REG. For NAT, performance in Slalom was associated with RFDmax (R2 = 0.213) while CF was the sole predictor for Giant-Slalom (R2 = 0.256), Super-G (R2 = 0.209), and Downhill (R2 = 0.488). For REG, variance in race time was substantially explained by CF (model R2 = 0.683). This study provides evidence of an event-specific relationship between performance and force production capacities and notably the importance of isometric critical force.