Nobody can hold her down, she's got to keep on moving!

Wareham resident Tara Greaves was diagnosed with lupus about eight months ago, and on April 15, she will run the Boston Marathon for the first time.

"Lupus is an autoimmune disease and it can attack your main organs like [your] liver, kidneys, brain, heart," Greaves explained. "At first, I was feeling kind of arthritic pain, and one day I was walking and I couldn't even get up the stairs."

She ran her first marathon in Plymouth in November 2012, and the runners she's met along the way have become an invaluable support system.

"When you're having that day when you're like, 'Oh my God, how am I going to get up today?' they'll be sending you a text: 'Are you doing all right?'" Greaves said.

Staying active isn't just a hobby. It's recommended by Greaves' doctors because it can help stave off the degenerative effects of the disease.

"I've got to keep moving. Literally," said Greaves. "I sort of started making this bucket list of what I wanted to do, especially after I found out more about the disease. … The minute I stop being active is when it can take over and become more painful."

Greaves is running the Boston Marathon in support of the Hopkinton-based nonprofit "Project Just Because," which provides a number of services to low-income families.

While she admits to being naturally competitive, beating the person next to her isn't the first thing on her mind for this race.

"I sort of have a goal to finish without getting hurt. ... Time's sort of out the window," Greaves said. "I'm just going to enjoy every mile."

In addition to running, Greaves does cross-training at CrossFit in Marion. CrossFit provides an intense workout that conditions every muscle group.

Her job working as a unit coordinator at South Shore Hospital in Weymouth keeps her on her feet and moving all day. She also tries to keep busy when she gets home.

"The only time I hit my rear end down is when I go to sleep," she said.

Greaves went up against the effects of the disease over the winter when a sinus infection — generally an unpleasant, but relatively mild ailment — knocked her on her back. It took her three weeks to recover, and when she did, she was right back on the road running for her quality of life.

But nobody said it would be easy.

"The first day I got back to working out again," she said, "I felt like I had been hit by a bus."

Another reason Greaves keeps on moving is to set an example for her three daughters.

"I want to show them that you don't give up."

Her 13-year-old twins, and her 16-year-old all attend Wareham schools, and her oldest has taken up her mother's sport, joining the track team this year.