CHRIS WALLER circles the horizontal bar with methodical precision, completing giant swings as though he were a human airplane propeller.
Then the gymnast becomes a rocket. Exploding over the top of the bar, he heads skyward, hangs in the air a split second, and drops to his feet on the mat.
Waller, here in Seattle for this weekend's international McDonald's American Cup meet, is upbeat about his practice routine. He is less confident, however, about the future of men's gymnastics in the United States.
Several universities have cut gymnastics from their men's varsity program, including his own alma mater, the University of California, Los Angeles (UCLA).
''It's a huge blow, not just to the athletes at UCLA but to the entire men's situation in the US,'' says Waller, who graduated in 1991 and now trains in Albuquerque, N.M. UCLA, where 1984 Olympic gold medalists Peter Vidmar, Tim Daggett, and Mitch Gaylord trained, cut its men's program last year.
''You can imagine what schools with weaker programs felt like,'' Waller says.
Though still popular among women, men's gymnastics has been sliding backward, as measured by high school and college support. Without enough college scholarships to bring promising athletes along, insiders say, the US will not be able to field strong national teams like that of 1984.
''It's hard for my parents to afford for me to go to college,'' says Richard Grace, a University of Nebraska senior who won a scholarship. He and Waller are on the 20-man US senior national team.
The plight of men's gymnastics came to the fore earlier this year when the National Collegiate Athletic Association considered whether to extend support for a men's gymnastics championship. NCAA rules say that a sport must be supported by 40 or more colleges; men's gymnastics has 33 colleges. The NCAA membership voted to continue the championship through 1997.
''That's a good, positive sign'' from the athletic community at large, says Fred Turoff, gymnastics coach at Temple University in Philadelphia. Yet it is unclear whether the battle has been won or merely postponed.
Kathryn Reith, spokeswoman for the NCAA, says the championship limit for any sport has already been lowered from 50 to 40 teams. The question now is whether further adjustments are needed. ''Where do you draw that line?'' she asks.
Other sports face this issue: This spring will be the last Division II championships in men's ice hockey and lacrosse. Water polo has just 41 sponsoring institutions.
''What does '40' mean?'' asks Francis Allen, who has coached the University of Nebraska men to eight national gymnastics titles. ''Why can't they set it at 20?''
About 16 colleges have said they will keep the sport for men even if the NCAA drops its sponsorship, Allen says. In his view, ''that's enough the keep gymnastics alive'' as a strong US sport.
Several factors work against less-popular sports. Fewer participants make it harder to organize competitions. Also, colleges are under pressure from federal equal-opportunity legislation (Title IX) to balance men's and women's sports. With budgets tight, this sometimes is achieved by cutting men's programs.
The NCAA's contract with CBS, mostly for its national basketball tournament, brings in $215 million a year. Of that, $33 million goes to fund championships in all other sports. The gymnastics championship costs $87,000.
At bottom, the issue is not money, the sport's participants say.
''It all boils down to exposure,'' says Ed Burch of Gold Cup Gymnastics, who is Waller's coach. ''The media attention is devoted to two sports -- football and basketball.''
He notes that grade schools and high schools are phasing out the sport. That's how he got involved in gymnastics, he says.
Yet the sport is not an easy one for most people to latch on to. It requires discipline, hours of hard work, and -- to reach the top -- sheer talent. ''Gymnasts execute, in a single evening, acts of greater daring and perform more muscular feats than some baseball and football players are called upon to do in an entire season,'' notes ''The Encyclopedia of Sports.''
According to USA Gymnastics, the sport's governing body in Indianapolis, 58,000 US athletes are in competitive programs. Girls outnumber boys 5 to 1.
Although 90 percent of US Olympic men's teams in recent years have come up through NCAA programs, gymnasts see some signs for optimism even if school support continues to drop:
*UCLA is still supportive of the sport in its new club status. The University of Washington in Seattle is among other colleges with strong club programs.
*The decline of the professional-style East bloc athletic programs should even out international competition.
*Success breeds interest, as Burch found in 1984. Enrollment in his club team soared after the US men's Olympic triumph.
*Several events this year are scheduled for national TV coverage, starting with the McDonald's American Cup tomorrow on NBC from 4 to 6 p.m. (EST).