Given the mind-boggling miles in their challenges, it's expected that ultra marathon runners will sometimes fall short of their goals.
Those like Ashley Kumlien simply start again.
In 2010, the 28-year-old founder of MS Run the US ran across the country, 3,200 miles in six months, to raise money for research to cure multiple sclerosis. She succeeded in completing the journey, but raised roughly 10 percent of the $500,000 she had sought to generate.
After a detour to Australia, she returned home to Brookfield and planned a new effort for 2013: a 3,000-mile relay with 22 runners tackling 140 miles each.
"There currently is no other event like it," said Kumlien, a Waukesha North High School grad. "The structure is unique, and we are offering runners the opportunity to run across a section of America for a week, as they test their physical capabilities while supporting a worthy cause."
Kumlien has always loved running, but draws ultra inspiration from her mother, Jill, who has been steadfast in her own 30-year marathon of life with the debilitating disease.
As Jill's muscles and motor skills deteriorate, her daughter applies her own to the cause.
In part to draw attention to MS Run the US, Kumlien has signed on to run all six races in the North Face Endurance Challenge, events ranging from 50 miles to 100. Earlier this month, she took second in the women's division and finished ninth overall in the Mohican 100, covering the century of miles on trails in Ohio in 23 hours, 56 minutes. It was one of the half dozen ultra marathons she has finished already this year.
Despite her success in the solo efforts, Kumlien realized after her cross-country venture in 2010 that she needed a team to push MS Run the US across that $500,000 finish line. Each runner on the relay will expand the charity's reach, and raise money on the way.
"Involving other runners is vital to the success of the organization and creating excitement around this unique event," Kumlien said.
In her mind, $500,000 is the charity value of a run across the country.
"If we can get it going, then years from now, $500,000 is going to be a small amount compared to what we can raise," she said.
As she plans the relay, Kumlien trains, works as a personal trainer at the Be Fitness and Wellness Center in Delafield, runs her own Fitness Journey Boot Camp and helps her mother maintain her own physical ability.
"I've noticed some progression in not having as much balance," Kumlien said. "Her fine motor skills are not what they should be. Her good days are now more spread out and her symptoms are more prominent.
"She's always willing to try. We definitely can't complain; she's still walking."
Jill's example inspires Kumlien to run and to work.
"I love what I do so it's easier to work 12 or 13 hours," she said. "I put my purpose and passion first.
"We don't have a cure so I want to keep fundraising until we have one. I see a really good vision for the future. I see a lot of potential for people to be inspired and to do more in their communities to motivate others."
To date, MS Run the US has received five applications to join the relay, and others can join via the Web site.
As Kumlien has shown time and again on the trails across the country, if she falls short in 2013, she'll start again.
Memories of running cross-country for the Slinger Owls motivated Tom Held to get his body moving again when he turned 30. Almost two decades later, he's still on the move. The 49-year-old bikes, runs and skis, and covers news for similarly active people as a freelance writer and blogger.
He spent 26 years as a daily news reporter, and applies that experience to dig out stories about athletes, races, endurance sports, fitness and self-propelled transportation. His work has appeared in Silent Sports Magazine, Wisconsin Trails and Cross-Country Skier.
Held lives in the Bay View neighborhood, where he counts being Dad to twin daughters part of his daily workout.