What is the optimal classical style sub-technique during uphill roller skiing in elite male cross-country skiers?

Abstract

Purpose To compare performance, physiological and biomechanical responses between double poling (DP) and diagonal stride (DIA) during treadmill roller skiing in elite male cross-country skiers. Method Twelve skiers (VO2peak DIAup; 74.7 ± 3.7 ml kg−1 min−1) performed two DP conditions at 1° (DPflat) and 8° (DPup) incline, and one DIA condition, 8° (DIAup). Submaximal gross efficiency (GE) and maximal 3.5 min time-trial (TT) performance, including measurements of VO2peak and maximal accumulated O2-deficit (MAOD), were determined. Temporal patterns and kinematics were assessed using 2D video, while pole kinetics were obtained from pole force. Results DIAup induced (mean, [95% confidence interval]) 13% [4, 22] better 3.5-min TT performance, 7%, [5, 10]) higher VO2peak and 3% points [1, 5] higher GE compared to DPup (all P < 0.05). DPup induced 120% higher MAOD compared to DPflat, while no significant differences were observed for VO2peak or GE between DPflat and DPup. There was a large correlation between performance and GE in DP and a large correlation between performance and VO2peak for DIAup (all r = 0.7–0.8, P < 0.05). No correlations were found between performance and VO2peak for any of the DP conditions, nor between performance and GE for DIAup (r = 0.0–0.2, P > 0.1). Conclusion At 8º uphill roller skiing, DIAup induce higher VO2peak, GE, and superior time-trial performance than DPup in elite male skiers. There was no difference between VO2peak or GE between DPflat and DPup. A large correlation was observed between DIAup performance and DIAupVO2peak, while DP performance was best correlated to submaximal GE.