Nina Martinez, right, and twin sister Marie required blood transfusions weeks after being born in 1983. Nina, who will run the Marine Corps Historic Half Marathon on Sunday, contracted HIV after her transfusion, and works today as an advocate on awareness and prevention. (Sara Wendland/Courtesy photo)

The athletic career of Nina Martinez began just nine short weeks ago, when the 29-year-old made a decision to begin training for Sunday’s Marine Corps Historic Half Marathon in Fredericksburg. The closest she has ever been to an athlete was in her own imagination two decades ago, when as an eight-year-old girl in 1992, she made up stories to her elementary school classmates that she was related to Los Angeles Lakers icon Magic Johnson.

He was the one person who knew what she was going through, the disease she was living with. Magic has AIDS, and so do I, she would tell them.

All these years later, Martinez, a Georgetown graduate now living in Atlanta, is poised to push her pain threshold to a new place on Sunday. She has never competed in a sport, and becoming physically active in just two months has taken a toll. She developed bronchitis halfway through training. She has tendinitis in her knee. And she has just recently learned how to take care of her feet, because for many weeks she was running in shoes a size too small.

“Running is no joke,” Martinez said.

Neither is living with HIV for 30 years. But that is exactly why Martinez is returning to the Washington area this week, to run under the flag of The Grassroot Project — a local HIV prevention nonprofit — and to show that she is not defined by an illness that crept into her life in 1983. She hopes to run as much of the half marathon as possible, having completed her training regimen without running outdoors, and her longest run clocking in at just over 11 miles on a treadmill last week. Sunday’s race is 13.1 miles long.

“I have friends that run, and hear their complaints, that it’s hard on the body, this, that and the other, and you know, part of it is well, ‘I’m an HIV patient,’ ” Martinez said. “I’ve had my fair share of physical discomfort. This can’t be that bad. It’s just challenging in a different way. In some respects being a patient prepared me to be a runner.”

The daughter of a U.S. Naval officer, Martinez and her twin sister, Marie, were born 12 weeks premature in San Jose, in June 1983, and both suffered from an anemic condition that required a blood transfusion two months after their birth. Marie received her transfusion in San Jose, while Nina was transferred to Letterman Army Medical Center in San Francisco to receive hers. Martinez received her blood from Irwin Memorial Blood Bank, which later would become a fixture of AIDS-related lawsuits across the country.

Eight years later, in December 1991, after the family had relocated to New Jersey, Martinez was diagnosed with AIDS after a pre-operative test for an eye surgery revealed her condition.

“We walked out of there like zombies,” said Martha Alvarado, Martinez’s mother. “My husband’s reaction was, he couldn’t tell anyone. All he told his family was to pray for us. He wanted everything scrubbed clean. He wanted a sterile environment.”

In the days after, Alvarado and her husband, Benjamin Martinez Jr., collected themselves. There was a measured anger, Alvarado remembers, questions of how this could happen (the family never pursued litigation, but opened a Department of Defense online investigation case, which led to a review of standardization of protocols for all blood product, tissue and organ donations across the armed forces, Martinez said). Eventually Nina was put on scheduled visits to Walter Reed National Military Medical Center.

Nina remembers the Magic Johnson announcement, and people talking about it — and that is how she comforted herself at school. The family decided the only way to move on was to be open. Alvarado told the school principals about her daughter. When Nina wanted her friends to sleep over, she told the children’s parents.

“We were too young to know, or learn that we should be uncomfortable with it, so that’s kind of a blessing for me. I never learned to be uncomfortable about it,” Martinez said. “To me it was something that was neat and something I associated with like, a famous athlete.”

She has never had a serious complication from the disease. She became an AIDS advocate when she arrived at Georgetown, and before she graduated in 2005, she was participating in research studies at the National Institutes of Health. She moved to Atlanta to pursue graduate work at Emory, eventually landing a job as a public health analyst at the Centers for Disease Control.

Tyler Spencer, who helped found The Grassroot Project, attended an AIDS awareness conference at a hotel in Atlanta in August of 2011. He was giving a presentation on his project on a sleepy Saturday morning that month, and after introducing himself as a former Georgetown student, a loud chant came from a woman in the crowd. “Hoya Saxa!” It was Martinez.

“I was thrown off by it,” said Spencer, who convinced Martinez to run in the Marine Corps Half Marathon this weekend. “It’s hard to put into words, her personality . . . she has this amazing sense of humor, but also this attitude that recognizes all the problems that we’re facing in trying to address HIV, and in some places, [where] we’re not doing a good enough job to address HIV.”

Martinez lives with her twin sister in Atlanta, and the two never talk about what would have happened had they switched places in California in 1983, preferring to think about all the places they still want to go in their lives. For Nina, one of those places will be Fredericksburg on Sunday, where she will be sporting new size 7 sneakers that Marie bought her recently.

“You have to show people how to move forward. You have to show them that they can still have a life, and still have a career. I have both,” Martinez said. “I will try to show them that they can run a half marathon.”