Physiological responses and performance factors for double-poling and diagonal-stride treadmill roller-skiing time-trial exercise.

PURPOSE: To compare physiological responses between a self-paced 4-min double-poling (DP) time-trial (TTDP ) versus a 4-min diagonal-stride (DS) time-trial (TTDS ). The relative importance of peak oxygen uptake ([Formula: see text]O2peak ), anaerobic capacity, and gross efficiency (GE) for projection of 4-min TTDP and TTDS roller-skiing performances were also examined.

METHODS: Sixteen highly trained male cross-country skiers performed, in each sub-technique on separate occasions, an 8 × 4-min incremental submaximal protocol, to assess individual metabolic rate (MR) versus power output (PO) relationships, followed by a 10-min passive break and then the TTDP or TTDS , with a randomized order between sub-techniques.

RESULTS: In comparison to TTDS , the TTDP resulted in 10 ± 7% lower total MR, 5 ± 4% lower aerobic MR, 30 ± 37% lower anaerobic MR, and 4.7 ± 1.2 percentage points lower GE, which resulted in a 32 ± 4% lower PO (all P < 0.01). The [Formula: see text]O2peak and anaerobic capacity were 4 ± 4% and 30 ± 37% lower, respectively, in DP than DS (both P < 0.01). The PO for the two time-trial (TT) performances were not significantly correlated (R2  = 0.044). Similar parabolic pacing strategies were used during both TTs. Multivariate data analysis projected TT performance using [Formula: see text]O2peak , anaerobic capacity, and GE (TTDP , R2  = 0.974; TTDS , R2  = 0.848). The variable influence on projection values for [Formula: see text]O2peak , anaerobic capacity, and GE were for TTDP , 1.12 ± 0.60, 1.01 ± 0.72, and 0.83 ± 0.38, respectively, and TTDS , 1.22 ± 0.35, 0.93 ± 0.44, and 0.75 ± 0.19, respectively.

CONCLUSIONS: The results show that a cross-country skier's "metabolic profile" and performance capability are highly sub-technique specific and that 4-min TT performance is differentiated by physiological factors, such as [Formula: see text]O2peak , anaerobic capacity, and GE.