Purpose: To investigate fluctuations in speed, work rate, and heart rate (HR) when cross-country ski skating across varying terrains at different endurance-training intensities. Methods: Seven male junior Norwegian skiers performed maximal-speed (V max) tests in both flat and uphill terrains. Thereafter, 5-km sessions at low (LIT), moderate (MIT), and high intensity (HIT) were performed based on their own perception of intensity while monitored by a global navigation satellite system with integrated barometry and accompanying HR monitor. Results: Speed, HR, and rating of perceived exertion gradually increased from LIT to MIT and HIT, both for the total course and in flat and uphill terrains (all P < .05). Uphill work rates (214  W, 298  W, and 350  W for LIT, MIT, and HIT, respectively) and the corresponding percentage of maximal HR (79.2% [6.1]%, 88.3% [2.4]%, and 91.0% [1.7]%) were higher than in flat terrain (159  W, 206  W, and 233  W vs 72.3% [6.3]%, 83.2% [2.3]%, and 87.4% [2.0]% for LIT, MIT, and HIT, respectively) (all P < .01). In general, ∼13% point lower utilization of maximal work rate was reached in uphill than in flat terrain at all intensities (all P < .01). Conclusions: Cross-country ski training across varying terrains is clearly interval based in terms of speed, external work rate, and metabolic intensity for all endurance-training intensities. Although work rate and HR were highest in uphill terrain at all intensities, the utilization of maximal work rate was higher in flat terrain. This demonstrates the large potential for generating external work rate when uphill skiing and the corresponding downregulation of effort due to the metabolic limitations.
Pål Haugnes, Jan Kocbach, Harri Luchsinger, Gertjan Ettema and Øyvind Sandbakk
Pål Haugnes, Per-Øyvind Torvik, Gertjan Ettema, Jan Kocbach and Øyvind Sandbakk
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.