Sprinting for 50 km!

What to make of a sport where the "sprint" distance is 1.5km, and the average speed of a skier can be quicker for a 50km race!  Cross-country skiers do generally have the highest VO2 max of any endurance athletes.  For comparison, the average speed for an Olympic level 100m runner is around 37 kph.  The average speed for the Olympic cross country skiing sprint champion in Sochi this year was around 26 kph (1.5 km in 3:28).  That is pretty quick.  Perhaps surprisingly, the average speeds for 15 km and 50 km races are slightly lower and slightly higher respectively (23 kph for the 15 km race and 28 kph for the 50 km race).  Average speed is dependent on the course, snow conditions and ski technique (classic vs. freestyle/skate).  However, for the 50 km average speed to be quicker than the sprint is a real eye opener.