To look at the number of entrants in the Marine Corps Marathon and to listen to the happy voices of its organizers, one would never know it is being overshadowed by not one, but two, marathons that are more prestigious, more important and much, much more lucrative.

This Sunday, while the New York City Marathon is being run before a nationally televised audience and hundreds of thousands of fans lining the sidewalks of New York, the Marine Corps Marathon will be held in relative obscurity around the monuments of Washington. There is no live TV, no prize money, no superstar. Grete Waitz, Juma Ikangaa and Bill Rodgers will run in New York. The John and Jane Does of marathon running will be here.

One week later, on Nov. 11, another marathon takes place, this one in Columbus, Ohio. Certainly not previously known as a marathoners' mecca, Columbus has been designated the training ground for U.S. marathon men leading to the 1992 Summer Olympics in Barcelona. The Columbus Marathon serves as the U.S. men's national championships and the trials for the world championships and Pan-American Games of 1991. It also will be the site of the 1991 national championships and, most significant, the 1992 men's Olympic trials. Bonus money will be awarded to winners and other qualifiers.

Because it plays such a big role in shaping American male marathoners, Columbus has siphoned off many of the area's best runners, men who otherwise probably would have run the Marine Corps Marathon. The 1988-89 champion, Jim Hage of Lanham, will not run Washington, but Columbus. Darrell General of Mitchellville, the top U.S. male finisher in this year's Boston Marathon, also is heading to Columbus, as is John Glidewell, a strong marathoner from Woodbridge.

But does this bother the people who run the Marine Corps race, which began in 1976 with little more than 1,000 runners and this Sunday will have its largest gathering ever, a full field of 13,000?

"We don't care," said Capt. Marshall Fields, coordinator of the race. "We have no problems with that. The purpose of our race is to promote physical fitness and a drug-free lifestyle. We get runners from all walks of life. The military makes up only about 8 to 10 percent of our runners. We cater to any runner; we don't cater to the elite runner."

These are three marathons with distinctly different purposes. New York is glitzy and high-brow, the product of the showmanship and creativity of its founding father, Fred Lebow. The world watches.

Washington is run by the Marines and is unfailingly no-nonsense. Locals watch.

Columbus is the creation of The Athletics Congress, the governing body of track and field of the United States, which wants a coordinated effort leading up to the Olympics. By necessity, people will have to pay attention.

New York and Washington have bumped into each other on the marathon calendar every now and then, but Columbus is relatively new on the scene. The top American men are going there, but since the top American men are not the world's best marathoners, this really doesn't affect New York.

"Some Americans will run in Columbus and if Columbus didn't exist, we'd have them," said Lebow, the New York race director. "The first American in Columbus gets into the world championships. In our race, the first American gets into the world championships only if he runs 2:12 or better. It's easier to make it in Columbus."

For a man seemingly so far above the world of normal marathoning, Lebow appreciates and respects the event the Marines put on. He said he always asks the Marines to send him entry forms so that those who don't get into his race (25,000 make it, more than 20,000 are rejected) might apply for Washington.

"I ran it a couple times," he said. "I love it. What a beautiful course. I'm salivating. Someone there could make a killing if they wanted to."

Lebow said if he were in charge of the race, he would change the name to the Washington, D.C., Marathon.

"The rest of the world doesn't know it's in Washington," he said. "They think it's held at a military base."

But Washington organizers revel in the misconceptions of New Yorkers.

"These are two major events, held on the same day, that are about as different as any two marathons could be," former Marine Corps Marathon coordinator Chip Olmstead said last year. "New York City is the biggest marathon in the world. We are the breeding ground for the first-time marathoner. We don't want to be what they are. We can't be. We look at it this way: Eventually, the guy who comes to our race two or three times goes to theirs."

This is the first time the Marine Corps Marathon has closed its entries and turned away runners. The Park Service told the Marines that 13,000 runners is enough to fill the streets of Washington.

"This is the first year we've had to apologize to people and tell them the field is closed," Fields said. "It's too bad, but it's a sign that we're doing well."