'40 Below' documentary follows the frozen competitors in 'the world's toughest race'

A person with a red face walking in the snow
"Epic" Bill Bradley during the brutally cold Arrowhead 135 race in 2019 when a polar vortex plunged Minnesota into dangerous cold. “I ran 50 miles like my life depended on it because it did. Because I finally did something that I felt good about again,” he said in the film. “And I just remember, ‘This is nothing compared to being in that bankruptcy.’”  
Courtesy of Marius Anderson | London Road Films

The Great Northern Festival in Minneapolis will present a sneak peek of a new documentary titled "40 Below: The World's Toughest Race." It features competitors from around the world in Minnesota's own infamously chilly ultramarathon, the Arrowhead 135. 

If there is such a thing as an ordinary ultramarathon — this ain’t it.

The course runs 135 miles along a snowmobile trail from International Falls south to Tower, Minn. Competitors can run, ski, or bike and those that finish, can take two days.  

An image of someone running in the snow
An image of "Epic" Bill Bradley running in the 2019 Arrowhead 135 ultramarathon. A competitor on foot, Bradley pulled his gear behind him on a specially built sled. He is one of the featured athletes in “40 Below: The world’s toughest race."
Courtesy of Marius Anderson | London Road Films

They can also choose to do the race in one of two ways: supported or unsupported.

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Supported means competitors are tracked and can use warming houses with food and hot beverages at the three checkpoints spaced about equally along the way.

Unsupported entrants aren’t tracked but do check in at the three race checkpoints. However, they are not allowed to enter the warming facilities or benefit from anything they offer. 

‘This is just crazy!’

The Arrowhead 135 purposely starts on the last Monday in January when temperatures are some of the lowest on Earth.

To compete, the race has a stringent vetting system — challengers must show proof of previous ultramarathon completions but having competed once they can return again without going through the process. The race cuts off at around 180 entrants to promote solitude on the trail. Typically, all spots fill up within a matter of hours. 

“I thought, 'Wow, this is just crazy!'” said Marius Anderson, the film’s director. “Like, who would do that?”

Anderson, a German, met his wife in Sweden and then moved to her hometown of Duluth in 2017. He said he learned about the Arrowhead 135 from his father-in-law.  

Anderson makes documentaries, and he decided the Arrowhead 135 would be his next film. During the 2019 running of the race, he profiled two people who had not just competed in the race — they'd done it a bunch of times.  

‘Self-doubt is a lie’

Duluth’s Leah Gruhn, a geologist, said her first Arrowhead 135 attempt was on skis, and she recalls “it didn't go so well.”

She ended up not finishing.  

Then Gruhn bought a fat-tire bike. She said she learned a valuable lesson when she competed in a 100-mile race on unpaved roads. It took Gruhn to her physical and emotional limits. She considered dropping out.

In the movie Gruhn talks about how she then noticed she had crossed the midway point, so it was just as far to go back to the starting line as it would be to finish. 

“I realized that self-doubt is a lie because that is just something your brain is telling you that has no basis in reality,” she said. “And serves no purpose other than keeping you safe from taking risks.”

People ride their bikes in the snow
Cyclist Leah Gruhn leads a pack of fat tire bike racers during the 2019 Arrowhead 135. The Ultramarathon always starts on the last Monday in January because that is usually the coldest part of the year.
Courtesy of Marius Anderson | London Road Films

Gruhn biked the Arrowhead 135 for the eighth time in 2019 . She says she's drawn to to the race because of “the prestige and reputation of the race as being at the coldest part of the winter in the coldest part of Minnesota, and it's the longest race of its type.”

The other subject of “40 Below” is a former California video store Baron who goes by the name “Epic” Bill Bradley.  

After streaming sank his business Bradley's life spiraled out of control. He filed for bankruptcy and his wife left him. He found himself isolated in his house alone. In the documentary he remembers how his father called him every night. When asked about that scene Bradley saw it as a test he survived.  

“I asked him later I said, 'Dad, how come you're calling me every night?' He goes, 'Son, I was doing a suicide watch, and I said, 'I must have passed, Padre.'

Woo-woo!" he recalled.   

In the movie Bradley gets emotional as he remembers how he decided to get through the ordeal by doing his first ultramarathon.  

“I ran 50 miles like my life depended on it because it did. Because I finally did something that I felt good about again,” he said in the film. “And I just remember, ‘This is nothing compared to being in that bankruptcy.’”  

With renewed focus Bradley began rebuilding his confidence. 

“So of course, I go 'Wow, if 50 feels this good I wonder what 100 would feel like?' And then it was like, 'I wonder what 135 would feel like in the desert, I wonder what 100 would feel like in Alaska?'” he said. “And then finally, 'Boy, I wonder what 135 would feel like in northern Minnesota, International Falls, the Arrowhead 135?”

“40 Below” captures the blistering cold in 2019. A polar vortex hit the state. The movie takes its name from how cold it got. Only a third of the competitors completed the race. 

However, director Marius Anderson says for the filmmakers the biggest obstacle wasn't the cold but gathering enough footage. 

“If you imagine watching a marathon somewhere, and a friend of yours is running the marathon, and you say, 'Yeah, I'm going to be on the side watching you,' you basically see that person, maybe for like, less than half a minute, you know, if you just stand somewhere on the side,” Anderson said. 

His crew was constantly on the move. Going from one trail crossing to another. Meanwhile the cold sapped the equipment. 

“Basically, you would already pan to the right, for example, and the screen that you look at would be delayed by like a second. It's kind of like wobbly in the screen, you know?” Anderson said. “I learned later that basically, those crystals in the LCD screen would just move much slower at that temperature.”

Competitors partway through the Arrowhead 135 Ultra race.
Competitors partway through the Arrowhead 135 Ultra race, where racers run, bike or ski in a 135 mile race through Minnesota's north woods in 2014.
Derek Montgomery for MPR News

Anderson said he hopes audiences are inspired by the documentary in the same way the competitors inspired him. 

“You know, I always ask myself, ‘What would Bill do?’ Like, ‘What would Bill do right now?’ I asked that quite often in my everyday life. And I know he wouldn't quit, he would just keep on pushing. And he would just do it again,” Anderson said.  

The sneak peek at the Great Northern Festival is sold out, but Anderson hopes a world premiere at a prestigious film festival will lead to wider distribution. He encourages people to check in with the film’s website for news, and about possible further local screenings.

Meanwhile, in just days, on the last Monday in January, competitors will assemble on the starting line in International Falls for the 2023 Arrowhead 135 to do it all over again.