This is a good long slow distance workout to do when you are in an area with big hills or mountains. The hike up is a fairly specific form of leg strength training for classic skiing as well as being a good aerobic workout. On the way down you get another type of leg strength workout and it is also a good way to work on agility. In general if a mountain takes 2 hours to hike up, it would count as about 2.5 hours of training since your heart rate on the way down will be low. If it is not too technical you can do a bit of running which will raise your heart rate.
Since I am training in Canmore this fall I thought it would be a good idea to take advantage of all that the area has to offer. I have done three mountain hikes and have seen some spectacular views and also lots of snow! I have found these hikes to be inspiring and a great variation to regular ski training.