Vasaloppet 90K in Sweden is the coldest ultra trail race I've done. It's the oldest, longest and biggest cross country ski event in the world.
In 1987 it was also the coldest: -33˚C (28˚F) as measured at the start in Sälen. It was quite an experience to be one of those 16,000 skiers freezing in long lines, waiting for the 8:30am gun. It was difficult to breathe in the cold air.
The start was delayed. A few buses full of competitors had died along the road there, and we had to wait about 30 minutes until they arrived. This is Sweden for you: we'll start all together, or not at all.
I remember my toes and fingers were pretty deeply frozen as everyone was desperately running around or hopping up and down. After the start there was a huge uphill, and chaotic queues quickly formed. I suppose the infamous ultra what am I doing here moment occured to many then, if not earlier.
The first Vasaloppet was held in 1922, when a Swedish newspaperman wanted to retrace the classic route from Sälen to Mora, made by young nobleman Gustav Vasa four centuries earlier, in 1520.
Gustav had been escaping from King Christian II. This mighty King of Kalmar Union (Denmark, Sweden and Norway) had just invited the Swedish aristocracy to 'a party' in Stockholm, only to have them all (including Gustav's parents) massacred.
Gustav had failed to convince the men in Mora to start a rebellion against the evil king, and he was headed towards Norway. However he was soon caught in Sälen by two quick Mora brothers on skis, who told him that people had changed their minds after learning about the new taxes. The Swedish people would fight for their freedom.
Three years later Gustav I was crowned King of Sweden. In those days Finland was a part of the Kingdom as well.
In 1972 Sports Illustrated had described Vasaloppet "One of the most bizarre, most foolish, most excruciating most exalted human events of our time." I knew right away that I had to do this crazy ski race! Much like the Hawaii Ironman (which I did the next year), this was a race you simply had to finish, at least once in a lifetime.
After a couple of hours the sun came up and the temperature warmed up to tolerable levels. After about each mila (Swedish mile, which is 10km) there was an aid station serving hot Ekström's blåbärssoppa, a blueberry soup actually made of bilberries, which grow abundantly in Scandinavia.
Everything was going well, except my skis: they seemed to slide more backwards than forwards. I had them rewaxed at every service point, but the ever-changing snow composition made wax selection too challenging for me.
Long story short, Anders Larsson won in 4:20, and I finished way later in 9:40. Somehow I must have felt a touch frustrated, as upon returning home I immediately cut my skis in pieces and burned them in a fireplace.
I have never done any classic style skiing since, but I've adopted the freestyle skating technique that doesn't require constant waxing. Later on I once skated 100 km as a fun training challenge by myself, and it felt a lot easier than Vasaloppet. The record-low temperatures in 1987 are the most probable reason for that.
Nowadays Vasaloppet week includes several shorter events as well. There are also American, Japanese and Chinese sister skiing races of Vasaloppet. In the summer there are VasaStafetten relay running race and CykelVasan, a popular mountain bike event. Heja Sverige!