Author(s): SCHORDERET, F., BOURDILLON, N., MOTTET, J., RABERIN, A., MILLET, G.P., Institution: UNIL: UNIVERSITE DE LAUSANNE, Country: SWITZERLAND, Abstract-ID: 609

INTRODUCTION:
At the Milano–Cortina 2026 Olympic Games, ski mountaineering (SkiMo) will debut with sprint and mixed-relay events that predominantly tax athletes’ capacity to repeatedly sustain short (3-10 min) supramaximal uphill efforts. While aerobic power is a key determinant of SkiMo performance in traditional endurance events (e.g., vertical and individual races), it remains unclear whether established laboratory assessments — such as incremental tests to exhaustion used to determine V̇O₂max and ventilatory thresholds, VTs — are relevant for elite sprint-specialized SkiMo athletes. Accordingly, this study aimed to compare aerobic and anaerobic characteristics responses between sprint- and endurance-specialized athletes using submaximal, incremental, and supramaximal laboratory tests.
METHODS:
Nineteen males (12 sprint- and 7 endurance-, Tier 4–5) from the Swiss National Team completed uphill (slope 25%) treadmill protocol including constant-load moderate-intensity square-waves, incremental test to exhaustion and constant-load supramaximal (120-130%) test. Pulmonary on-phase V̇O₂ kinetics, VTs, V̇O₂max, plateau duration at V̇O₂max, blood lactate responses, and work above VT2 were measured.
RESULTS:
Endurance athletes exhibited significant higher V̇O₂max (74.7 ± 5.2 vs 69.2 ± 4.6 ml/min/kg, p = 0.031) and maximal vertical velocity (2196 ± 156 vs 2056 ± 122 m/h, p = 0.043) than their sprint- counterparts. In contrast, V̇O₂ kinetics (τ1: 23.5 ± 2.3 vs 24.3 ± 2.8 s, p = 0.331), V̇O₂max plateau duration (135.0 ± 26.9 vs 142.3 ± 49.0 s, p = 0.743), peak lactate value (12.9 ± 2.5 vs 12.9 ± 1.9 mmol/L, p = 0.992), and lactate clearance kinetics did not differ between the two groups. During supramaximal bout, sprint specialists demonstrated a greater supramaximal work capacity (24.0 ± 3.6 vs 17.3 ± 2.8 kJ, p = 0.002) and a distinct temporal pattern of lactate recovery (time × specialization interaction, p < 0.001), despite similar peak lactate values.
CONCLUSION:
At the elite level, SkiMo specialization reflects divergent physiological demands, favoring aerobic power in endurance athletes and supramaximal work capacity and glycolytic capacity in sprint-specialized athletes.

These findings indicate that although traditional aerobic testing remains essential, it is insufficient to discriminate between sprint- and endurance-specialized athletes in elite SkiMo. The addition of supramaximal exercise protocols yields critical complementary information and more accurately reflects the physiological demands imposed by contemporary Olympic SkiMo formats.