"You take some photos and head back to the office Monday with some war stories," said Maier, a 31-year-old who runs a gym in Washington.
With most of the participants wearing one of McCarthy's $300 rucksacks filled with bricks, the challenge lasts between eight and 10 hours, with participants covering 15 to 20 miles and performing tasks that involve carrying heavy objects — including one another — that have some connection to the city where the event is being held.
McCarthy said in an interview Friday that he is stunned by how popular the event has become.
"It started out with a backpack nobody wanted to buy and with only a few people interested in trying the challenge," said McCarthy, who was discharged from the military in 2008. "The people who have started to come out to do the challenge have made the challenge what it is. It is their unbridled passion. We're trying to answer the demand."
McCarthy said that those who complete the challenge —typically around 95 percent of those who start — show the same kind of resolve as he did in perfecting the manufacturing process on the small black rucksack.
"It's about not cutting corners, doing the right thing hard over the easy thing easy," he said. "Ninety percent of the work with the backpack came in getting the last 10 percent of it made. It's the same with the challenge. The last 10 percent is where most of the hard work comes."
Pollitt-Cohen believes it was fate that brought her to her current position as director of the Goruck Challenge — the first event in San Francisco in 2010 was on her birthday. Initially run in connection with Tough Mudders, which holds events for as many as 10,000, the Goruck Challenge typically has groups no larger than 40.
Considering its roots, the Goruck Challenge certainly has a military theme. According to Maier and Devin Reagan, who will help lead the Baltimore challenge, participants are often asked to envision themselves as part of theU.S. Army's Special Operations unit. Part of each admissions fee is donated to the Green Berets, according to Pollit-Cohen.
"You're going to get a feeling of what it's like to be in Special Forces," Pollit-Cohen said. "It's a great way to impart their lessons."
Maier, who participated in his first Goruck Challenge in December in Washington, was part of a group of seven from his gym. He eventually teamed up with Reagan, who was also doing the challenge for the first time after having served in the same Colorado unit as McCarthy.
"You really don't know what to expect," Maier said. "I thought I was going to be ready, but it's all being part of a team. It's not like running a 5K or 10K, or even a marathon. You're not going to be successful if you don't work together."
Among the tasks Maier completed was carrying a tree trunk weighing several hundreds of pounds over the Key Bridge to Roosevelt Island and running through Rock Creek Park "at 3 in the morning in water that is waist deep." The challenge finished by ascending the steps of the Lincoln Memorial en masse — like a bunch of real-life Rockys at the Philadelphia Art Museum, the finish for that city's event.
Though plans for the Baltimore challenge won't be disclosed officially until the start of each day of the two-day event — the first beginning at 1 a.m. Saturday and the second starting at 10 p.m. that night — they will likely include a route similar to last year's, which took participants to the Inner Harbor, Oriole Park, Federal Hill, the Edgar Allen Poe House & Museum and other city landmarks.
Reagan said that in doing what organizers call "route reconnaissance," city officials, in particular the police, are notified. Reagan said it is not usual when the Goruck Challenge is held in a city for the first time that "a bunch of cops pull up when they see people wearing black and carrying backpacks running around at 4 or 5 in the morning."
Reagan, who holds the rank of Sgt. First Class, said that while Green Berets and others in Special Operations can often be trained for weeks at a time with similar tasks that push them to the brink mentally and physically, the eight to 10 hours those spend at the Goruck Challenge "puts them in the league with the real thing."
Maier, who plans to do future challenges, said "it's a great way to see a city on foot" and added, "You make some friends, you get your butt kicked and then you think you'll never do something like this again."
But then, Maier said, "three or four days later, it's like pregnancy, you forget all the pain and you think about the good parts."
Charles "Kit" Klein is what McCarthy and others former Green Berets who run the challenge call "a repeat offender." Since participating in the third-ever challenge in New York in November 2010, the 26-year old from Philadelphia has signed up for five more. He will be in Baltimore next weekend.
"It's different than anything I had ever done," said Klein, who like most of those who participate had no military background. "I was looking for something exciting to do. It's about the team, and pushing yourself physically and mentally more than you think is possible."
Among the most grueling tasks Klein has performed is carrying a 250-pound team member the length of three football fields in Philadelphia. But there's always the fun part, including two-member pushups (each have their legs on the other's back) in downtown Manhattan.
"I have a tremendous respect for Jason McCarthy and the others who have the military backgrounds," Klein said. "It gives me a chance to see what they have done — the pain and the suffering that they call 'good living' because of the way it makes you feel afterward."
How to sign up
When: Saturday and next Sunday
Entry fee: $160 (go to goruckchallenge.com for more information)