BOSTON -- Running 26.2 miles and putting your body through the rigors of a marathon isn't fun for many people.

But Red Sox wives Kathryn Nixon, Dawn Timlin and Shonda Schilling won't be thinking of the pain but rather the joy they will be bringing to so many lives as they all run the 110th annual Boston Marathon on Monday.

All three will be running for a particular cause, looking to raise money and awareness for their respective charities. Nixon will be pounding the pavement for the Dana-Farber Marathon Challenge, which directs 100 percent of money raised to the Claudia Adams Barr Program in Innovative Basic Cancer Research.

"That's what gets you through the whole marathon," said Nixon, who is running Boston for a third time. "In the past, I've run with ribbons. On each ribbon is a friend, loved one or family member that has battled cancer or is going through cancer right now. So, I have all of them right there with me.

"I also carry a sheet of the Jimmy Fund, in memory of kids and the ones who are being treated right now at Dana-Farber [Cancer Institute]," she said.

This marks the 17th year of the Dana-Farber Marathon Challenge's association with the Marathon.

Schilling and Timlin will run on behalf of ALS research, with Timlin looking to raise awareness for the Angel Fund, a non-profit organization dedicated to ALS investigations at the Cecil B. Day Laboratory at Massachusetts General Hospital.

"We had read an article by Kristen Armstrong in Runner's World in which she was dedicating each mile to someone, whether it was someone with an illness or in praise of that person, being thankful you have that family member," Timlin said.

"It comes down to being out there for those who can't be. And really why we run, besides we enjoy it, is because we have to remember there's a lot of people who wish they could be out there," Timlin added.

Timlin, who finished in 4:09:42 in 2005, said she will try to put fatigue in the back of her mind when she races for the third time Monday.

"There are some athletes I've seen who have been taken by the disease," she said. "They would do anything to be out there, training and complaining like we have. [At] mile 21, when you're going up [Heartbreak Hill], you're definitely thinking, 'I'm making [it] through here because they wish they could but they can't.'"

Schilling will be running in the Boston Marathon for the second time. She finished in 5:08:30 in 2005 and also ran in the 2005 Phoenix Marathon. The Red Sox ace's better half is raising funds and running on behalf of The SHADE Foundation of America, which she founded in August 2002 after her successful battle against melanoma. The foundation's mission is to eradicate melanoma through the education of children and the community in the prevention and detection of skin cancer and the promotion of sun safety.

"I know one lady who was a marathon runner and she's in her 50s and she's confined to a wheelchair and the excitement she gets out of e-mailing me and talking. I'll be thinking about her a lot," Schilling said.

"And for me, running the marathon was my way of taking back my life after I was diagnosed with melanoma. Being so afraid to go outside and just recently had to go to a funeral of a 28-year-old, it's just a reminder for me."