摘要：•
Maximizing recovery time improves sprint cross-country skiing performance.
•
Less than 22 minutes between the semi-final and final may inhibit performance.
•
Shorter recovery time between repeated ski sprints limits blood lactate recovery.
•
In competition conditions, selecting an earlier quarter-final heat is recommended.
Background
In a sprint cross-country (XC) ski competition, the difference in recovery times separating the first and the second semi-final (SF) heats from the final (F) may affect performance. The aim of the current study was to compare the effects of longer
vs. shorter recovery periods prescribed between the 3 knock-out races of a simulated sprint XC ski competition involving a prologue (P), quarter-final (QF), SF, and F.
Methods
Eleven well-trained XC ski athletes completed 2 simulated sprint XC ski competitions on a treadmill involving 4 × 883-m roller-ski bouts at a 4° incline using the gear 3 ski-skating sub-technique. The first 3 bouts were completed at a fixed speed (P
FIX, QF
FIX, and SF
FIX) corresponding to ∼96% of each individual's previously determined maximal effort. The final bout was performed as a self-paced sprint time trial (F
STT). Test conditions differed by the time durations prescribed between the QF
FIX, SF
FIX, and F
STT, which simulated real-world XC ski competition conditions using maximum (MAX-REC) or minimum (MIN-REC) recovery periods.
Results
The F
STT was completed 5.4 ± 5.5 s faster (
p = 0.009) during MAX-REC (179.2 ± 18.1 s) compared to MIN-REC (184.6 ± 20.0 s), and this was linked to a significantly higher power output (
p = 0.010) and total metabolic rate (
p = 0.009). The pre F
STT blood lactate (BLa) concentration was significantly lower during MAX-REC compared to MIN-REC (2.5 ± 0.8 mmol/L
vs. 3.6 ± 1.6 mmol/L, respectively;
p = 0.027), and the pre-to-post F
STT increase in BLa was greater (8.8 ± 2.1 mmol/L
vs. 7.1 ± 2.3 mmol/L, respectively;
p = 0.024). No other differences for MAX-REC
vs. MIN-REC reached significance (
p > 0.05).
Conclusion
Performance in a group of well-trained XC skiers is negatively affected when recovery times between sprint heats are minimized which, in competition conditions, would occur when selecting the last QF heat. This result is combined with a higher pre-race BLa concentration and a reduced rise in BLa concentration under shorter recovery conditions. These findings may help inform decision making when XC skiers are faced with selecting a QF heat within a sprint competition.
Graphical abstract
Image, graphical abstract
