On the surface, cross country skiing seems akin to something like running. You primarily work at a steady pace with occassional extra effort on a climb or a brief moment of respite downhill. However, competitive cross country skiers in both sprint and distance events have a much more variable output.
In most races, the terrain is split evenly between climbing, going downhill, and flat. However, about 50% of the time is spent climbing, which makes sense because climbing is the slowest section. Each segment (up, down, or flat) though is typically between 10 and 35 seconds (at most 70 seconds). That means that a racer switches between extremely high intensity above VO2 max levels to bouts of recovery, which is very similar to high intensity interval training workouts.
So what does this means for how a racer’s body works? Our bodies have two main energy systems: anaerobic and aerobic. The anaerobic system works without oxygen and works at high intensity but it is functional only on a very short term (seconds). The aerobic system, on the other hand, needs oxygen to operate and can function for much longer periods, but it can’t reach the same level of intensity. If we look at across country ski race that takes around 30 minutes to complete, a racer would spend significant time in their anaerobic system as they climb the various hills while they recover on the flats and downhills in their aerobic system.
By contrast, most other activities of a similar duration do not have the same bursts a high intensity and athletes operate at a more consistent level within the aerobic system.
Why does this matter? I’m not an elite cross country ski racer but I do participate in a range of activities, mostly of the endurance variety. It seems like running, biking, and cross country skiing should all benefit each other and they do, but this research makes me think about how much my training for dragon boating, which is much more anaerobic, may contribute to my skiing.
Based on the fact that local stores sold out of cross country skis very quickly at the start of the season there are presumably a lot of people learning how to ski this year. I wonder how the trails they choose for their first experiences affects their perceptions of the sport. If you’re expecting a steady state and you have bursts of super intense because you chose a hilly course do you go back and do it again? Obviously the efforts are different for a brand new skier compared to a racer but I can’t help but wonder if the lack of people I’m actually seeing out on the trails compared to how many people have bought the equipment has something to do with expecting one type of workout and then choosing a trail that gives you a very different experience.