Race Against Time : Health: Ric Munoz, a long-distance runner who is HIV-positive, will compete in the Boston Marathon today and try to better his mark of 2:52.

In the five years since Ric Munoz learned he had the AIDS virus, he has watched his time grow short.

As short as 2 hours and 52 minutes, to be exact.

When the West Hollywood runner makes his stoop-shouldered way to the start of the Boston Marathon today, he will be out to cut that time, his personal record for a 26.2-mile race.

He will not think about the virus inside him that is, so far, little more than an abstraction in an otherwise healthy life. Or about how many more starting lines he will get to see. Winning is out of the question--the leaders will beat him by more than half an hour. He will think about 2:52.

Munoz, 34, a legal secretary, was running marathons sporadically before finding out he was infected with HIV. Since then, hard running has become his obsession and possibly his best friend in his fight against the onset of AIDS.

“He doesn’t talk about death and dying. He talks about the next race,” said Barry Norcross, co-founder of Frontrunners L.A., a gay and lesbian running club to which Munoz used to belong.

Last year, Munoz set a goal of racing in one marathon a month, then completed a punishing 14 races all over the country. Most were under the three-hour time that weekend marathoners use to mark the best among them. This year, Munoz’s itinerary has a different twist: eight marathons, ending with his 50th in Hawaii.

Munoz has smiled patiently through warnings that his hobby is perhaps not the best course for someone with HIV. He knows that people concluded from Earvin (Magic) Johnson’s retirement last fall that athletics and the AIDS virus do not mix. But Munoz said he has watched too many infected friends succumb to what he calls a “death sentence mentality.”

“You always have to have something to look forward to,” Munoz said. “If you rid yourself of that habit, you’re asking for it.”

Munoz’s physician, Steve Knight, credits his patient’s rugged training with helping him stay healthy. Knight said the running, besides offering physical benefits, is an important emotional weapon in treating the human immunodeficiency virus.

Munoz said he has never felt better, especially since shedding 30 pounds over the past two years with a vegetarian diet. His times dropped with his weight, and he said he plans to keep running for as long as possible.

Munoz is well-informed and open about his condition. He said he was not surprised to find out he was HIV-positive--”I was sexually very active, very active”--and has tried hard to avoid the gloom others seem to want to attach to it. Friends describe him as irrepressible--as fanatical about Bruce Springsteen and the TV soap opera “As the World Turns” as he is about running.

“The sound of the clock in your head is there ticking. You try to do as much as you can before you can’t do any more,” Munoz said. “If and when the time comes for me to begin the process of dying, I can look back without a trace of doubt and say: ‘I put everything I could into this.’ ”

Munoz ran his first marathon on a lark in 1983--he finished in a surprising 3:20--and raced in a dozen more over the next five years. By late 1990, he was hooked. He shed his paunch, ran a lot more races and began his marathon-a-month effort, which he calls his proudest achievement.

For Munoz, marathons have become one way of coping with the virus, an important calming escape from the slivers of fear that pierce his quietest moments. And racing has given him a model for facing the uncertainties of the future.

“I know that by the 22nd mile, not once have I gotten through it without feeling some sort of discomfort,” Munoz said. “I know it’s going to happen, but it works to my advantage because I can prepare for it and block it out mentally.”

Munoz takes the drug didanosine, or DDI, to slow the virus, which two years ago had reduced his level of T-helper cells--important soldiers in the body’s immune system--to below normal.

Though some medical research suggests that the body’s ability to fight viruses and infections dips for several hours after a marathon, AIDS experts, who generally recommend exercise for their patients, doubt that long-distance racing presents any special threat to those with HIV or AIDS.

“Those who are healthy enough to run 26 miles--and the rest of the body is able to do it--they’re basically healthy,” said Wilbert C. Jordan, an AIDS specialist at Drew University of Science and Medicine in Los Angeles.

Jordan said he is treating four HIV-infected marathoners, including one with AIDS symptoms.

Amy Ross, a former AIDS researcher and a marathon-running friend of Munoz, said his successes have forced her to rethink her position after she cautioned him a few years ago that the grinding strain of marathons might leave him susceptible to disease.

“The fact that he can do this is inspirational to everyone, not just people with HIV,” Ross said.

Even before Munoz nudges into the starting pack today, he will have fashioned a victory for himself. “I’m just an average person. I work in an office,” he said. “There’s nothing in my life that anyone would call glamorous. But there’s plenty of corporate CEOs who’d love to be able to run a sub-three-hour marathon.”