LEAD: In a land where more than 60 percent of the people are nomads, living in the deserts with the cattle, camels and sheep they raise, heroes are in short supply, most of them men of the sword or cloth. LEAD: In a land where more than 60 percent of the people are nomads, living in the deserts with the cattle, camels and sheep they raise, heroes are in short supply, most of them men of the sword or cloth. In the rare event one of another ilk emerges, it is usually by happenstance and quite unexpected. Abdi Bile Abdi, for example, never imagined he would be perceived in such a lofty manner. He was like any other child growing up in Somalia, a poor nation of more than seven million people, mostly Moslem, on the eastern shoulder of Africa. Even after he left in 1983 to attend school and run track a continent away, he had no sense of how his triumphs would touch his country. Abdi Bile Biography Then, he returned home for several weeks, and he was flabbergasted. Everywhere he went, from the capital city of Mogadishu to the small village of Las Anod where he was born, he watched in amazement as his countrymen strained to shake his hand, to touch him, cheering all the while, raising their fists in symbolic gestures of nationalistic pride and triumph. Abdi Bile, as he is known in the West, reviews the scene in his mind again and again and still seems astonished. ''The people were everywhere,'' he said the other day, sitting in the bleachers that overlook the track at George Mason University. ''Wherever I went, there was a big welcome. I expected some, but not exactly how big as this. Just to walk around in the cities and towns and everybody recognizes my face, it was kind of exciting. The people, they gave me back motivation and energy.'' The moment that had touched them came in the long shadows of a September afternoon last year in Rome, the final day of the world track and field championships. With 10 finals on the program, the old Stadio Olimpico pulsated with excitement, and now it was time for the 1,500-meter race. Bile (pronounced BEE-lay), who had run the fastest times in the heats and semifinals, took his place among the 12 finalists. Steve Cram, the former world record holder, was there. So was Jose Luis Gonzales, the Spanish champion. ''I did not know what to expect,'' Bile said. The pace was slow, but time does not necessarily matter in a big race. Cram led at 1,200 meters but Bile caught him and won in 3:36.80, beating Gonzales and Jim Spivey of the United States by more than a second. To that point, most of those in Somalia familiar with Bile's activities knew him only as a good athlete, little more. Soccer is the national passion, not track and field. Long after his victory, he would encounter friends who said: ''Oh, yes, I saw you race on TV. That was a marathon, wasn't it?'' Bile would laugh and tell them, ''I don't run the marathon.'' He didn't mind. When a country has not won a world championship in anything, what possible difference could the distance of the race matter when it finally did? When Bile landed at the Mogadishu airport in December, among those who greeted him was Somalia's President, Maj. Gen. Mohammed Siad Barre. Over the next 25 days, Bile traveled the country in a private plane. Upon arrival, he was driven to the center of each town along roads lined with cheering Somalis. ''It was the most incredible thing I've ever seen,'' said John Cook, Bile's coach at George Mason, who watched videotapes Bile brought back. ''People stood 5 and 10 deep to see him, singing, chanting. You'd have thought he was the Pope.'' Bile's father is called Bile Abdi. He is a nomad who lives outside Las Anod with his cows, camels, sheep, goats and horses. His mother, Hawo Osman, one of Abdi's four wives, lives in Las Anod with a daughter, another of Abdi's 15 children. All Abdi's children grew up in Las Anod, tended to by Abdi's brother, Mohammmed Abdi, a police officer who made sure the children received proper housing and schooling. Bile, now a 25-year-old student in marketing, is the oldest child and, like most Somalis, played soccer as a youngster. He never thought about running until one day, just for fun, a friend coaxed him into running 400 meters with him. Bile finished in 56 seconds, which was not a bad time, considering the track was dirt and he ran in soccer shoes. Two days later, with the coach of a regional team watching, he ran another 400, finishing in 55 seconds. The coach asked him to come back the following week and try again. Bile said no, he didn't like running that much. But his friends talked him into it, and he finished in 53 seconds. ''At that point,'' he said, ''the coach told me not to do anything, take five days off, come back and run again. This time, I ran in 51 seconds. So I went from not doing anything to running the 400 in 51 seconds.'' Bile was 18 years old at the time; the best nonaltitude time at 400 meters then was 44.26 seconds. Still is. His progression from there was furious. Joining the regional team, he competed at 400 meters, then three months later at 800 meters and four months after that at 1,500. By the summer of 1982, as a member of the national team, he ran the 800 and 1,500 in the East African Games and the African championships in successive weeks. He did not especially distinguish himself but he was convinced, with proper training, he could excel. Meanwhile, Bile had developed a friendship with another Somali runner, Jama Aden, who had left the country to attend Fairleigh Dickinson University in New Jersey on a track scholarship. Whenever Aden came home to visit, Bile asked him about the United States, about college, training methods and track facilities. ''He always asked questions,'' said Aden, now a graduate assistant at George Mason. ''He wanted to know about training with me. I told him I would try to find him a school.'' Aden had known Cook from college meets and liked him. Also, George Mason made sense because of its proximity to Washington and the international nature of its population. When Bile stepped off a plane at Dulles Airport in July 1983, Cook had known him only through Aden's descriptions. Within two years, he understood why Aden had raved so much. At the 1984 Los Angeles Olympics, Bile's first worldwide competition, he made the semifinals in the 1,500. A year later, he won the IC4A and N.C.A.A. titles. He missed most of 1986 because of injuries but returned last year to win another N.C.A.A. title, the Grand Prix championship at 1,500 meters and then the race in Rome. In movie theaters in Somalia, before the featured attractions, they sometimes show films of Bile's victory in Rome. When he crosses the finish line, people jump to their feet in the darkness to cheer. ''It's funny,'' he said. ''So many people are not really aware of track and field. If I finished second in a time of 3:29, that would not make sense to them. The world championships, that makes sense to them. They understand what it means, winning the world championships.'' Bile is tall and thin, with a circular face and soft features. He laughs easily, and this makes him laugh: Las Anod, which is called L.A. by Somalis, is in a region called Sool. ''So, you see? The '84 Olympics were in L.A. Now, they are in Seoul.'' He shrieks with laughter. In every other way, he views the Olympics more seriously. He knows they are bigger than Rome, more important, and Somalia has never won a medal. Winning the gold in the 1,500, he said, ''would be the greatest day of my life'' but not only for the obvious reasons. In all of Somalia, a country the size of California with a per capita income of about $300 a year, there is no track. Nor do the schools offer physical education programs. Children run on dirt and grass. So do the regional teams. Because of his victory in Rome, he has noticed that many more young people have shown an interest in running. But without proper programs or facilities, he fears their new enthusiasm might be blunted. ''A lot of people have the potential,'' he said. ''They need someone to encourage them; they need to get facilities. To win a gold at the world championships or the Olympic Games, to be successful, at least they should have a track and some programs.'' For now, he can only help the cause by his performance in Seoul. ''I have the confidence,'' he said. ''If things go well and I stay healthy, I am capable of winning.''