Purpose: To investigate the contribution from maximal speed (Vmax) and %Vmax to the finish sprint speed obtained in a cross-country sprint in the classical and skating style, as well as the coinciding changes in kinematic patterns and the effect of pacing strategy on the %Vmax. Methods: Twelve elite male cross-country skiers performed two 80-m Vmax tests on flat terrain using the classical double-poling and skating G3 techniques, followed by 4 simulated 1.4-km sprint time trials, performed with conservative (controlled start) and positive (hard start) pacing strategies in both styles with a randomized order. In all cases, these time trials were finalized by sprinting maximally over the last 80 m (the Vmax section). Results: Approximately 85% of Vmax was obtained in the finish sprint of the 1.4-km competitions, with Vmax and %Vmax contributing similarly (R 2 = 51–78%) to explain the overall variance in finish sprint speed in all 4 cases (P < .05). The changes in kinematic pattern from the Vmax to the finish sprint included 11–22% reduced cycle rate in both styles (P < .01), without any changes in cycle length. A 3.6% faster finish sprint speed, explained by higher cycle rate, was found by conservative pacing in classic style (P < .001), whereas no difference was seen in skating. Conclusions: Vmax ability and %Vmax contributed similarly to explain the finish sprint speed, both in the classic and skating styles, and independent of pacing strategy. Therefore, sprint cross-country skiers should concurrently develop both these capacities and employ technical strategies where a high cycle rate can be sustained when fatigue occurs.
Pål Haugnes, Per-Øyvind Torvik, Gertjan Ettema, Jan Kocbach and Øyvind Sandbakk
Guro Strøm Solli, Pål Haugnes, Jan Kocbach, Roland van den Tillaar, Per Øyvind Torvik and Øyvind Sandbakk
Purpose: To compare the effects of a short specific and a long traditional warm-up on time-trial performance in cross-country skiing sprint using the skating style, as well as related differences in pacing strategy and physiological responses. Methods: In total, 14 (8 men and 6 women) national-level Norwegian cross-country skiers (age 20.4 [3.1] y; VO2max 65.9 [5.7] mL/kg/min) performed 2 types of warm-up (short, 8 × 100 m with gradual increase from 60% to 95% of maximal speed with a 1-min rest between sprints, and long, ∼35 min at low intensity, including 5 min at moderate and 3 min at high intensity) in a randomized order with 1 hour and 40 minutes of rest between tests. Each warm-up was followed by a 1.3-km sprint time trial, with continuous measurements of speed and heart rate. Results: No difference in total time for the time trial between the short and long warm-ups (199  vs 200  s; P = .952), or average speed and heart rate for the total course, or in the 6 terrain sections (all P < .41, η2 < .06) was found. There was an effect of order, with total time-trial time being shorter during test 2 than test 1 (197  vs 202  s; P = .004). No significant difference in blood lactate and rating of perceived exertion was found between the short versus long warm-ups or between test 1 and test 2 at any of the measurement points during the test day (P < .58, η2 > .01). Conclusions: This study indicates that a short specific warm-up could be as effective as a long traditional warm-up during a sprint time trial in cross-country skiing.