The days are past when the United States routinely staged its Olympic swimming trials, read with interest the names of the qualifiers and prepared to celebrate their return with most of the Games' medals.

Despite surprising setbacks in the 1976 Olympics at Montreal and the 1982 World Championships in Ecuador, however, the U.S. is not prepared to accept the end of its dominance in the sport. Instead, officials of United States Swimming are working harder to revive the happy times of 1972, when Mark Spitz's seven gold medals helped the men win the heralded "Battle of the Sexes," 9-8, as the U.S. captured 17 of the 29 swimming events.

Over the Memorial Day weekend, young swimmers from across the nation--boys born in 1969 and girls born in 1970--will attend 13 training centers, to perform the same exercises at the same time with the idea of finding out which are particularly suited to the pursuit of success in the pool.

"The Soviets and East Germans have prospered through an early identification program, where they send young athletes to training centers and even relocate their parents in new jobs," said Don Gambril, the U.S. Olympic swimming coach.

"We'd never do that, but we must do something. The success of the Eastern bloc nations has exploded in all sports, and we in swimming are one of the last holdouts trying to keep them from completely dominating. We are tring to restructure everything, looking ahead to 1988 and 1992.

"In the past, we had superior coaching, more facilities and a great population. Like the economy, that did not hold up and now we have to plan for success, instead of just letting it happen."

Officials of the sport hope that those who receive high scores at the USS training centers will be motivated to stay active, rather than drift off, as so many have, to football, basketball, soccer and track. If family finances and circumstances can handle it, talented youngsters from areas with little competition will be encouraged to move to swim country in Florida or California, to work with high-powered clubs.

There is no question that the 1980 Olympic boycott hurt U.S. swimming, a sport in which rewards are measured in medals rather than in monetary benefits.

"We'll never know how much talent we didn't get because we weren't on TV for 200 hours from Moscow," Gambril said. "When Mark Spitz won his medals in 1972, and was on TV so much of the time despite the limited coverage in effect then, hundreds of parents wrote and called for information on how to get their kids involved in swimming. We didn't get that in 1980."

What the swimming people have gotten instead is a reduction in college scholarships from 18 to 11, elimination of the sport by financially pressed schools (San Diego State is the most recent) or consolidation of the men's and women's programs under a single coach.

The saviors of the swimming program have been the corporate sponsors--Arena USA, Phillips 66 and McDonald's, who have underwritten various championships and training programs. McDonald's built the Olympic pool in Los Angeles, which will be available for other events afterward.

There is no direct aid to the athletes, as there is in track, because FINA, the international swimming federation, has not approved trust funds for training. Additionally, the swim folks are extremely cautious about NCAA rules, since most U.S. amateur swimmers are products of collegiate programs.

U.S. swimmers are eligible for a variety of competitions in this pre-Olympic year, with the National Sports Festival, World University Games and invitational meets at both the Olympic site and Tokyo. Participation in each depends on the individual swimmer's training plans, but everyone who is healthy will be in Clovis, Calif., Aug. 3-6, for the USS Long-Course Championships that also serve as the trials for the Pan American Games.

Pan Am swimming competition in Caracas is the highlight of the 1983 U.S. schedule, with many swimmers eager to show South Americans that they are better than performances at Guayaquil would indicate.

"A couple of key people--Rowdy Gaines, Mary T. Meagher and Craig Beardsley--lost at Guayaquil and it took on the appearance of a disaster," said Ray Essick, executive director of United States Swimming. "Actually, we swam pretty well. Our girls did a fine job, but as happened in 1976, the DDR (East German) girls were better.

"I think that will provide a stimulus for us this year and next. Those swimmers who lost in the Worlds don't want to go out on a losing note. Rowdy Gaines is really motivated because he didn't win there. We may have made some mistakes in planning for the meet, but that's hindsight. You've got to have big shoulders."

Planning for the Olympics will be much easier, of course, since they will be held in this country. But the coaching staff is not just waiting for the opposition to arrive. While George Haines guides the U.S. team in Caracas, Gambril will be in Rome, watching the European Championships.

"I'll be coordinating our scouting, because most of our key Olympic opponents will be swimming in Rome," Gambril said. "But I'll also be talking with our athletes, at the National Sports Festival and the Pan Am Trials. We want to maintain a dialogue with our swimmers."

"We're trying to identify each major event, in a semieducational manner," Essick said. "Somebody from the Olympic staff will be there to talk with the kids. Next year, when we put our team together, the kids will have met a member of the staff and they'll know other members of the team. That should take some of the trauma out of it."

Some victories in Caracas should prove helpful, too, and the United States expects to cart a lot of gold and silver through Venezuelan customs. Except for a few good Canadians and the rare South American star like Brazil's Ricardo Prado, the United States should dominate Pan Am competition.

"The Pan Am Games have more political impact than swimming impact," Essick said. "If we send a poor team, we're criticized for not taking it seriously. If we send a good team, we're criticized for taking advantage of the little guy."

This summer, the little guy had best beware.

Next: gymnastics.