Physiological factors associated with ski-mountaineering vertical race performance

Abstract

Despite their increasing popularity, there are no studies analyzing the performance of ski-mountaineering vertical races. For the first time, this study examined a vertical competition, exploring the association between laboratory measures and uphill performance by means of multiple regression analysis. Nine high-level ski-mountaineers (age 20.6 ± 3.0 years, VO2max 69.3 ± 7.4 mL/min/kg) performed an anthropometric assessment and a laboratory ski-mountaineering graded exercise test (GXT) to evaluate VO2max, gross efficiency (GE), ventilatory thresholds (VTs), blood lactate thresholds (LTs), as well as the power output associated with these indices. Race characteristics in terms of vertical gain, length, and mean gradient were, respectively, as follows: 460 m, 3 km, 15.3% for junior men and senior women; 600 m, 3.5 km, 17.1% for senior men. Average race time was 23:35 ± 01:25 (mm:ss). Mean power output exerted during the race was 3.40 ± 0.34 W/kg, equal to 79.0 ± 3.5% of maximal and 95.3 ± 5.2% of VT2 calculated in the GXT. The most performance-correlated variable was the VO2 at VT2 (mL/min/kg) (r = 0.91, p < 0.001), which accounted for the 80% of performance variation (adjusted R 2 = 0.80, p = 0.001). When GE was included in the analysis, the regression model was significantly improved (adjusted R 2 = 0.90, p = 0.031). The study showed that the mean power output sustained during a vertical race is close to the power associated with VT2 and it is highly correlated with athletes’ physiological characteristics. Particularly, two variables, VO2 at VT2 and GE, measurable with a specific GXT, accounted for the 90% of performance variation in a ski-mountaineering vertical race. Accordingly, training programs should focus on the maximal development of VT2 as well as on increasing GE by technical improvement.