Comprehensive analysis of performance, physiological, and perceptual responses during an entire sprint cross-country skiing competition

Purpose To investigate performance, physiological, and perceptual responses of an entire sprint cross-country skiing competition in the skating style.Methods Eighteen national-level male junior skiers participated in a simulated competition comprising an individual time trial (TT), followed by three heats (quarterfinals [QF], semifinals [SF], and final [F]). Participants' heart rate (HR) was continuously monitored while perceived readiness (RED, 1-10), rating of perceived exertion (RPE, 6-20), and blood lactate [La-] were assessed at standardized time points.Results The total duration and distance covered were 03:30 +/- 00:06 h and 25.2 +/- 2.9 km, respectively. The participants spent 02:19 +/- 00:27 h > 60% of their maximal HR (HRmax) and 00:16 +/- 00:04 h > 85% of HRmax. Average HR decreased from TT to F (89.3 +/- 2.0% vs. 86.9 +/- 3.0% of HRmax, P < 0.01). [La-] levels were highest before (4.6 +/- 2.0 vs. 2.9 +/- 1.2, 3.2 +/- 2.0 and 2.5 +/- 1.3 mmol<middle dot>L-1, all P < 0.01) and after (10.8 +/- 1.4 vs. 9.8 +/- 1.6, 9.1 +/- 1.8 and 8.7 +/- 1.7 mmol<middle dot>L-1, all P < 0.05) F compared to TT, QF, and SF, respectively. RED was lowest before F compared to TT, QF, and SF (6.6 +/- 1.4 vs. 7.9 +/- 1.1, 7.6 +/- 1.1, and 7.4 +/- 1.4, respectively, all P < 0.05) while RPE was highest after TT compared to QF, SF, and F (17.8 +/- 0.9 vs. 15.1 +/- 2.0, 16.5 +/- 1.2 and 16.6 +/- 1.8, respectively, all P < 0.01). The six best-performing skiers demonstrated higher RED before F (7.2 +/- 0.9 vs. 5.3 +/- 1.2, P < 0.05) and higher [La-] after F (11.2 +/- 0.2 vs. 10.2 +/- 0.3, mmol<middle dot>L-1, P < 0.05) than lower-performing competitors.Conclusion This study provides novel insights into physiological demands of an entire sprint cross-country skiing competition, which involves repeated 3-min high-intensity efforts interspersed with > 2 h (25 km) of low- to moderate-intensity exercise.