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

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 (VO DIA; 74.7 ± 3.7 ml kg min) performed two DP conditions at 1° (DP) and 8° (DP) incline, and one DIA condition, 8° (DIA). Submaximal gross efficiency (GE) and maximal 3.5 min time-trial (TT) performance, including measurements of VO and maximal accumulated O-deficit (MAOD), were determined. Temporal patterns and kinematics were assessed using 2D video, while pole kinetics were obtained from pole force.

Results: DIA induced (mean, [95% confidence interval]) 13% [4, 22] better 3.5-min TT performance, 7%, [5, 10]) higher VO and 3% points [1, 5] higher GE compared to DP (all P < 0.05). DP induced 120% higher MAOD compared to DP, while no significant differences were observed for VO or GE between DP and DP. There was a large correlation between performance and GE in DP and a large correlation between performance and VO for DIA (all r = 0.7-0.8, P < 0.05). No correlations were found between performance and VO for any of the DP conditions, nor between performance and GE for DIA (r = 0.0-0.2, P > 0.1).

Conclusion: At 8º uphill roller skiing, DIA induce higher VO, GE, and superior time-trial performance than DP in elite male skiers. There was no difference between VO or GE between DP and DP. A large correlation was observed between DIA performance and DIA VO, while DP performance was best correlated to submaximal GE.