Posted on Jan 29

Grossman Trains for 100-Miler in His Sleep

By: John S. Forrester for New Balance

Grossman Trains for 100-Miler in His Sleep

If you think a 100-mile race sounds like a daunting challenge, consider ultrarunner Dominic Grossman. He’s doing two this year.

As the New Balance outdoor ambassador prepares for the Sean O’Brien 50-miler in Malibu, Calif., on Feb. 1 -- his first race of the 2014 ultra season -- Grossman is using some unique training methods to tackle the bigger distances.

“You can’t just be talented and win a 100-mile race,” Grossman says. “You have to be really smart. You have to really know yourself. You have to train in very unconventional ways that test your limits in training and in the race.”

From sleeping in a tent that mimics high altitude conditions to using a mobile app on his daily runs to compete against other runners’ times, technology is aiding the ultrarunner in training for the big goal races of the summer. The Sean O’Brien is a “tune up race,” Grossman says, that will “expose any glaring weaknesses” in his training and performance.

“You’re doing something where it isn’t really guaranteed that you’ll finish, but [it’s] definitely challenging and a very complete test of the human body.”

As race day nears, New Balance caught up with Grossman to see the innovations behind his training.


Grossman is so dedicated to his performance that he even trains in his sleep. Because the ultrarunner lives and trains near sea level in Los Angeles, Calif., just south of Los Angeles, he has to train his body to perform at higher elevations by sleeping in a high-altitude, low-oxygen tent: a plastic enclosure covers his bed as low-oxygen air is pumped in to simulate high altitudes.

“That’s been my limiting factor – how hard I can breathe. My legs are pretty strong. My heart’s pretty strong. But I’ve always had a little bit of an O2 limit in races,” Grossman says.

After a less-than-perfect 100-mile race two years ago in Colorado, the Los Angeles-based runner recognized that his performance was thwarted by insufficient acclimatization. Later, Grossman learned that the winner, who also lives at sea level, used an altitude tent while training for the race.

“I realized that if I want to do these high-altitude races, I needed to either move to Colorado or get an altitude tent,” he says.

Grossman bought his tent last May and sleeps in a low-oxygen environment every night, save for when he is recovering from races. The low-oxygen environment boosts his red blood cell count, and Grossman says he sees improvements in his performance at elevation.

“You can set up what altitude you want to be at. I usually sleep around 7,000 to 9,000 feet,” he says. “It’s kind of like you’re training at night because your lungs are working a little bit harder.”

“It’s all part of making the most out of every part of your day,” says Grossman.


Part of any runner’s training regimen is setting goals, increasing distance and speed over time, and monitoring progress. To finish a 100-mile race – and win – this is doubly important for Grossman.

“Either you do a lot of training in advance of a race and your race goes a little bit better, or you suffer hard on race day if you don’t train as much,” he says.

As the race date of the Sean O’Brien 50-miler approaches, Grossman runs 20 to 30 miles a day on the weekends and 10-mile tempo runs during the week. As mileage ramps up, he keeps track of his progress on a GPS-enabled mobile app called Strava.

The app allows users to track their times and personal bests on specific sections of roads and trails. It also gives runners the ability to compare their times against the stats of other Strava users who have run the same stretches.

“It lets me compete against other people -- their old times, what they ran the day before or the year before -- and I can see how I stack up,” says Grossman. “It helps my form and my stride because I’m constantly thinking, ‘OK, how can I iron out a few more seconds or a few more minutes out of this route?’”

An active user for the last eight months, Grossman says the app helps him stay “more in tune” with his progression in training by using Strava’s data to assess his times and speed on the roads and trails he regularly runs.

Beyond the technology he uses and the time spent running, Grossman says that mental preparation is perhaps the most major component of his training.

“It all comes down to being mentally ready for race day, visualizing it. Going down to the course and visualizing what type of pain you’ll be in.”

The duality of running, posits Grossman, is that he runs to compete and win, but also to test his capabilities.

“I think my real thing that keeps me going every time is discovering more about myself,” Grossman says. “When really sharp pain shoots through my body, I figure out how to deal with it, rather than saying that’s all I can get out of my body.”


To read more about Grossman and his training for ultras, follow our coverage at and visit his blog at

Photos and video courtesy of Dominic Grossman.

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