When Natasha Alam was diagnosed with Hodgkin's (search) lymphoma last March, she wanted something more to look forward to than the end of chemotherapy.

So the 28-year-old New Yorker decided to run a half-marathon in San Francisco (search). She began training, running only a mile a day when the chemo made her particularly sick.

She joined Team in Training (search), a national fund-raising group for the Leukemia & Lymphoma Society.

"I wanted to remember there was a bigger picture than what was just going on with me; there are other people suffering," Alam said.

Distance running is becoming more mainstream, and charity events are a big reason, experts say. More than $560 million was raised for charities in 2003, an 8 percent increase over the previous year, according to USA Track and Field. Figures for 2004 have not been released, but if the trend continues, even more money will be raised.

"Charitable running has really increased the popularity of the sport," said Jill Geer, USA Track and Field spokeswoman. "Just the fact that we are doing surveys on how much money is being raised through running shows how popular these events are."

There are more than 4,000 sanctioned races per year, including everything from 5Ks (3.1 miles) to marathons.

Every race has some runners for charities. "That's a lot of people," Geer said.

Some events, such as the Komen Race for the Cure series, are noncompetitive and devoted entirely to the charity. The 5K run started in Dallas more than two decades ago with 800 runners and has 110 races nationwide. It raised nearly $60 million last year.

"We have a lot of breast cancer survivors who take part in the race," said Susan Decker, a Komen Foundation director. "It really is moving to get out there and run, or walk, and see these women by your side. It's a great motivator."

Team in Training takes a more extreme approach, with participants running competitively. They work in groups with trainers to prepare for a half-marathon, full marathon or triathlon. Last year the program raised $60 million for the leukemia and lymphoma research.

"You run a marathon to accomplish something; you're facing a challenge you must overcome," said Liza Munson, national director for Team in Training. "That's why we do this. It's symbolic of the struggles and challenges with blood cancer."

Team in Training participates in at least 60 events worldwide, including the Boston Marathon on April 18, Munson said. The oldest marathon in the country accepts 1,000 charity runners who don't have to meet qualifying times to get in.

"There are precious few ways to run the Boston Marathon," said Guy Morse, director of Boston Athletic Association. "This is a way for those running for significant charities to have a shot at it."

Since 1994, when the Boston Marathon first accepted charity groups, those organizations have raised more than $56 million, he said. Morse expects about $8 million to be raised during this year's race.

Morse said those running for charity don't get in the way of the 19,000 others who qualified for the race.

"We have strict requirements to run. The charity runner must know road running etiquette, and be part of a legitimate training program."

Some regular marathon runners, though, have problems with charity runners, contending they are sometimes poorly trained and don't know road etiquette.

"Charity runners aren't motivated by breaking four hours at Boston, so they are a lot more laid back, and their goal is to finish the race," said Hal Higdon, author of "Masters Running."

"In a lot of ways that seems rational, but it can be seen as nuisance to a hard-core runner who's trying to break that record."

Higdon, who has run 111 marathons, agreed that the number of people running for charity has skyrocketed in the past 10 years.

"There are these little tent villages for the charities at races," he said. "They sure have more fun than we used to, running like crazy trying to beat our best times."

Still others run for individual causes. Los Angeles resident Patti Goldman is traveling to Cincinnati May 1 for the Flying Pig Marathon and is soliciting pledges to help pay medical bills for her friend Fidel Martinez, who collapsed while running and had emergency heart surgery. So far she has $1,000 in donations.

"I started running because I wanted to do a marathon when I turned 50. And now it's a part of my soul, and I thought it fitting to help a fellow runner this way."