Midway through today's Baltimore Marathon, when her feet start to blister and her legs start to burn, Beth O'Grady will look toward heaven and ask her brother for help.
"OK, Steve, we're halfway there," she'll say. "Give me strength."
Eight times, the Salem, Mass., woman has completed a marathon to honor her brother, Stephen, killed by a drunken driver in 1999. His death spurred O'Grady, 48, to begin long-distance running - both to assuage her grief and to start a memorial in his name.
Having raised nearly $30,000, she's still at it.
"Doing marathons [has] been a huge release for me and a way to raise money for the causes Stephen loved," O'Grady said. "Running isn't easy. Anything over 20 miles is pure hell and sends you digging deep into your gas tank. But my brother pushes me on."
One incentive: a photo of O'Grady taken at the finish of her first marathon:
"It shows a ray of light from the sky that landed right at my feet," she said.
O'Grady is one of a growing number of entrants in the Baltimore Running Festival who are competing for personal or charitable causes, or both. Of today's nearly 18,000 entrants, 794 told officials they are running for altruistic reasons, that is, something other than personal gain. That figure has more than doubled since 2002, the first year such records were kept.
Race organizers say those numbers largely reflect people running to raise money for well-known humanitarian causes, such as cancer research and curing diabetes. But how many more are quietly motivated to run in memory of loved ones - a brother killed in Iraq, or a favorite uncle now gone?
Today's marathon is No.14 for Skyler Steinman, who found catharsis in the races after family members were diagnosed with serious illnesses. In 2003, Steinman's brother developed leukemia and his father Parkinson's disease.
"I was desperate, a dead man walking," said Steinman, 36, of Bellevue, Ky. "I'd run before for peace of mind, but not until things came crashing down did I decide to do a marathon. What I got, at the end, was an electric feeling and a change in the trajectory of my life. I knew that one marathon wouldn't be enough.
"Standing in a crowd, before a race, making small talk with strangers, I find that others have great causes that they are running for. You tell each other, 'Don't quit.' A marathon is a quest to accomplish something in the midst of the everyday challenges we all face."
His father and brother struggle on, Steinman said. But each has managed to attend one of his marathons.
"My races give them something else to think about," he said. "Obviously I can't cure them, but running allows me to say, 'This is the one thing I know how to do for you other than to pray.'"
Steinman and others discover that running need not be a one-way street, experts say.
"Running can be a purely narcissistic endeavor, and many feel it doesn't provide the fulfillment they are looking for," said Jim Taylor, a consulting performance psychologist in San Francisco. "They enter a race looking for inner peace, but when they can't find it at the finish line they ask, 'Is that all there is?'"
Increasingly, they latch onto a cause, said Taylor, who has run 12 marathons himself.
"A lot of people who would never run more than five miles are inspired to do a marathon to help others," he said. "Whether you're running for Aunt Sarah or to cure AIDS, it gives the experience more meaning."
Ben Roberts weighs 250 pounds and would not be running in today's 5K race had he not learned of a friend battling cystic fibrosis. He has raised $500 for the cause.
"I hate running," said Roberts, 28, of Elkridge. "After 15 minutes, I feel like I can't catch my breath. But then I think, 'Come on, this little girl feels like this all her life. If she can get through it and not complain, then how can I not?'"
The 5K will be Sharon Williams' first run.
"I'll be out there hoofing it, in pain and agony," said Williams, 46, of Monkton. Her job as legislative advocacy manager for hereditary hemorrhagic telangiectasia, a rare blood disorder, has compelled Williams to wear an HHT T-shirt and become a jogging billboard.
"When I remember the phone call from a woman in Tennessee whose child had died in her arms from this disease, well ... it gives you a forum to run," she said.
Those who run for a cause are rarely saddled with a fear of athletic failure, said Joel Fish, director of the Center for Sport Psychology in Philadelphia.
"That extra layer of motivation shifts one's goals and takes the pressure off," Fish said. "People who run to 'give back' feel they succeed just by being in the race. There's really no way to lose."
Chris Brennan won't win the marathon, having pushed his twins in a double stroller for 26.2 miles. One son, Ryan, has autism; the other 6-year-old, Sean, has apraxia, a motor speech disorder.
Wheeling the pair through the streets of Baltimore will make his day, said Brennan, 37, an attorney from Princeton, N.J.
"Running marathons with my sons has strengthened our relationships," he said. "Last year, I did [Baltimore] with Ryan, whose autism makes meaningful family time difficult. But he laughs and smiles when we're running and takes uncharacteristic pleasure in watching the rustling trees or seeing a piece of paper being blown down the street."
In mid-race last year, a neighborhood kid Ryan's age jumped into the empty seat in the double stroller.
"Ryan laughed and gave him a hug," Brennan said, dumbfounded. "That spontaneity was a breakthrough."
Crossing the finish line today will be bittersweet, he said.
"For four hours, at least, Ryan will have been 'in the moment,'" Brennan said. "The race brings my son back into our world for a time."