A year ago, Neil Glenesk finished third in the World Modern Pentathlon Championships, the first American to capture an individual medal in 18 years. For his pains, which were considerable, he received no recognition.

"Our director of development called Sports Illustrated and told them about it and asked if they could at least put one sentence in 'For the Record,'" Glenesk said. "They said things were tight and they didn't have room."

This spring, however, the 5-foot-6, 190-pound Glenesk found a way to break into print. After reading a lengthy spread on an "Iron Man" stunt competition in Hawaii, Glenesk wrote Sports Illustrated a letter to the editor, and it was printed.

"They didn't print the whole thing and it made me look a little like a jerk, a hardcore complainer," Glenesk said. "The Iron Man thing was just one of several articles they ran, like a bicycle hill climb, little funny things that were pretty neat, but published at the expense of other sports. I always thought Sports Illustrated covered all sports and I couldn't understand why they wouldn't cover ours.

"You wonder sometimes why you bother doing something that nobody cares about. It's a little disheartening, to work so hard and get no recognition. We have to act as our own PR agents and I'm probably one of the best at it. Still, after a few years you mature and realize everything you do is for personal goals."

The modern pentathlon is derived from glamorous antecedents, in the tradition of an imprisoned soldier who steals a horse, escapes through adept use of sword and gun, has the horse shot from under him yet still swims and then runs back to his own lines.

In reality, it requires years of hard work and the slim rewards are largely confined to the respect of one's competitors.

"It takes four or five years to get hold of the three skill sports," said Glenesk, now 26. "I started in 1971 and it was 1977 before I felt confidence for the first time when I mounted a horse. In high school and college (Chico State), I was pretty good in both swimming and cross country, but I just wasn't big enough for water polo, my favorite sport.

"After I started the pentathlon, I would try to bluff the first three events, maybe get 700 points each, and then score as many points total in the swimming and running. It was getting me on teams, but nothing internationally.

"So I devoted more time to learning the tricks of riding, fencing and shooting. I think I'm good enough now that I can call myself a pentathlete."

Glenesk is here for the National Sports Festival, where competition begins on Friday. The pentathletes, however, went through the riding phase of the five-day test last Friday at their base in Fort Sam Houston, Tex., because of the difficulty in transporting suitable horses here. Glenesk did well, 1,060 points of a possible 1,100 and this event means more to him than to most.

For one thing, it is his last major competition of this pre-Olympic year, because he placed fifth in the U.S. Championships two weeks ago and did not qualify for the World Championships in Budapest, Aug 12-16.

"I decided I owed myself more than sports, so I went back to school and got a degree in biology (at Trinity University in San Antonio)," Glenesk said. "I'm going to study optometry at Cal-Berkeley next year. So I had only six weeks to train and, with a bad knee that hampered my running, I didn't make it.

"I can just imagine at the World Championships, where the same guys show up year after year, the Russians standing around and saying, 'What happened to Glenesk? Did he die?' It's unfathomable to them that we send new people in a sport where experience means so much. One told me once, 'we are so happy with your system.' But I made it by luck, the first time when I really wasn't one of the top four, and it helped me.

"By not making the team I know I'll have to work harder. I'm looking for pluses. I guarantee that if I don't make the Olympic team in 1980, four people will have had to do extremely well to beat me."

If Glenesk makes it to Moscow, he will be awrae of many of the tricks of trade. Selection of horses, for example, always has provided an opportunity for shenanigans.

"The Italians like to choose the horses by using a chessboard," Glenesk said. "You pick up a piece and on the bottom is the number of your horse. Sometimes, from the results, you know somebody had an idea of what piece to pick.

"The Russians used to put the numbers on the horses' hooves. They say once when an American drew a good horse, they caught them trying to erase the number. But I think after that Onischenko incident at Montreal, the Russians will be so wary of any questionable tactics, there is nothing to fear."

Boris Onischenko is the Olympic pentathlete who rigged his epee to score hits without a touch. He was caught and ejected when a hit was registered as an opponent clearly backed away.

"Everybody thinks it was a fencer who did it, not a pentathlete, so even that detracted from our publicity," Glenesk said. "It's funny how the only way we get publicity is when the news is something bad. In 1976 a guy was kicked off the team for insubordination and it got headlines. Once one of our guys pulled a drowning man from a river but the man died and the headline read 'Pentathlete Can't Save Swimmer.'"

All this is not to make the reader think that Glenesk merely goes through life complaining.

"I yearn for recognition but deep down I don't consider myself as anybody spectacular. I'm just Neil Glenesk, the shortest pentathlete in the world." CAPTION: Picture, The field in 3,000-meter steeplechase goes over and through water jump. Henry Marsh was Spartakiade winner. AP