Effect of drafting on heart rate in cross-country skiing

The purpose of this study was to compare the heart rate responses during cross-country skiing as a leading skier, as well as in a drafting situation, 2 m behind the leader. Six male cross-country ski racers, paired for VO2max skied a 2-km course (two loops of 1 km) using the skating techniques at a fixed speed (5.6 m.s-1) on two different occasions, once as a leading skier, the other as a drafter. A recovery period of 30 min was allowed between the two trials. Heart rates (HR) were monitored every 5 s during all performances. Capillary blood lactate concentrations were taken before and at 5 min posttrial. Results revealed that HR were significantly lower (154 vs 163 beats.min-1) when skiing behind another skier as opposed to leading. Lactate concentrations were not significantly different between the two trials. Results also revealed that projected frontal areas appeared to influence the effects of drafting such that the HR differences between the leading and the drafting situations were larger for smaller skiers drafting behind larger skiers. These results showed that skiing behind another skier in a ski race would be very advantageous when the situation is encountered and that coaches should use the drafting situation in training so that athletes can practice this energy-saving strategy.