I was inspired to create the documentary 40 Below when I heard my in-laws talking about a crazy race in the coldest city in the U.S. This is a place where temperatures reach, yes, 40 degrees below zero! They said that people run, bike or ski 135 miles while carrying all the supplies they need to survive. I thought … that’s impossible! I am from Germany and I have never heard of a place that got so cold. I couldn’t understand the appeal of doing that for over 50 hours with little or no sleep. I heard about people hallucinating (one saw a moose dancing in front of him) and how more than half the people who start don’t finish. The more I researched about the Arrowhead 135 in International Falls, Minnesota, the more I wanted to know. Why would anyone subject themselves to the toughest race in the world? What can we learn from them?

So, I decided to find out. I contacted the race director and asked for permission to film. Then I grabbed my cameras and my warm weather gear (by now I had some, because I live in Minnesota) and decided to see what it was all about.

I met Bill and Leah, the main subjects of the film, and spent time with them while they trained. Bill was fascinating to me because he tried seven times to complete the race, but never succeeded. Yet he kept coming back. He also had a past he was trying to purge. Leah, a junk food-eating scientist, has a different approach to competing. Her husband is with her every step of the way.

On the days leading up to the race, I interviewed other athletes and volunteers and I filmed the preparations. I also realized that on the day of the race I couldn’t be everywhere all at once. I asked around in my network of camera people who would usually leap at the chance to work on a new documentary project. As I explained the circumstances, everyone I talked to was suddenly very busy. I decided that, as a full-time director of photography myself, I would have to film as much as possible on my own. Though I did eventually find two additional stalwart camera people who were willing to help on the day of the race.

During production, I had to store spare camera batteries as close as possible to my body to keep them from freezing. I almost got frostbite, at times could barely move my fingers, but I did manage to sleep a few hours in a cabin near the race route. I felt lucky compared to the athletes. Over those 60 hours, I experienced the joy, the sadness and the defeat by observing some of the best endurance athletes in the world.

In the end, I learned that the most important thing in life is to try. This is a lesson that anyone can appreciate, not just outdoors enthusiasts or athletes. I hope that people who watch this film will get a sense of the camaraderie, community, and goodwill that springs from this race. And I hope they’ll begin to wonder what they can do to push themselves off the couch and out of their comfort zone and try something new, whatever that may be.