Purpose: As cross-country sprint competitions rely on maximal-effort durations of ∼3 min, a significant anaerobic energy contribution is expected. Anaerobic energy production during supramaximal exercise has been estimated in different sports from the accumulated oxygen deficit (ΣO₂ deficit) but, to date, not in cross-country skiing. Therefore, this study investigated the relative contribution of the aerobic and anaerobic energy systems to performance in ski skating sprint time trials using V1 and V2 techniques.
Methods: Twelve elite senior male cross-country skiers participated in the study (24 ± 3 yr, 183 ± 5 cm, 79 ± 7 kg, V˙O(2max) = 72 ± 3 mL·kg⁻¹·min⁻¹ or 5.7 ± 0.5 L·min⁻¹). Three submaximal trials (4°-6°), one V˙O(2max) test (8°), and one performance test (7°, 600 m) were performed both in the V1 and in the V2 ski skating technique on a roller ski treadmill.
Results: ΣO₂ deficit was ∼60 mL·kg⁻¹ and contributed to ∼26% of the total energy release during the ∼170-s time trials. Low to moderate correlations (r = 0.09-0.51) were found between O₂ cost of skiing, fractional utilization of V˙O(2peak), fractional utilization, and 600-m time. However, a moderate to strong correlation was found between ΣO₂ deficit and 600-m time in both the V1 (r = -0.75) and the V2 tests (r = -0.64) (both P < 0.05). No significant differences were found between techniques according to 600-m time or physiological responses.
Conclusions: The contribution from anaerobic energy systems was ∼26% and seemed independent of technique. In a group of elite skiers, the difference in roller ski treadmill sprint performance is more related to differences in anaerobic capacity than maximal aerobic power and O₂ cost.