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 (PFIX,QFFIX,and SFIX)corresponding to ～96％ of each individual\'s previously determined maximal effort.The final bout was performed as a self-paced sprint time trial(FSTT).Test conditions differed by the time durations prescribed between the QFFIX,SFFIX,and FSTT,which simulated real-world XC ski compe-tition conditions using maximum (MAX-REC) or minimum (MIN-REC) recovery periods.Results:The FSTT 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 FSTT blood lactate (BLa) concen-tration 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 FSTT 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.