There are hosts of young athletes here who can't wait to show you their latest inward 2 1/2 pikes or triple axels. They will get their chance as the sixth annual National Sports Festival officially opens Friday, featuring current greats and up-and-comers.

More than a quarter of a million fans are expected on the Louisiana State University campus during the two weeks of the sports festival, which essentially is a gathering of 3,300 athletes competing in 34 Olympic and Pan American sports, including indoor winter sports such as hockey and figure skating. The athletes are divided into four regional teams -- East, West, North and South -- that compete against each other.

This year's festival marks a new effort by the sponsoring U.S. Olympic Committee to make the competition an important step toward the Olympics. In fact, a name change is being contemplated, and a new name, it generally is assumed, would include the word "Olympics."

"I believe we're in an evolutionary period," said USOC Secretary General George D. Miller. "I think we're going to see it grow in importance, and there is going to be a visible link with the Olympics. As a result of that, it will continue to attract more and better athletes and emphasis."

While most countries long have held national competitions to sharpen their athletes, the U.S. is a relatively late starter. When the USOC held its first festival, in Colorado Springs in 1978, only 2,000 spectators attended the opening ceremonies.

It is now a 12-day event and a crowd of more than 70,000 is expected for the opening ceremonies at Tiger Stadium. Forty-eight medalists from the 1984 Los Angeles Games are here, including runner Valerie Brisco-Hooks and diver Greg Louganis. ESPN will provide 39 hours of television coverage.

The festival also will include drug testing, although it was announced today that athletes in three of the biggest sports -- boxing, basketball and track and field -- will not be included in the testing. More than 350 athletes will be selected at random, tested and the results examined at a Los Angeles laboratory.

Because of administrative problems, the national governing bodies for basketball and boxing have not yet signed an agreement with the USOC to allow the testing, but are expected to. The Athletics Congress, the governing body for track, has signed the agreement but was unable to change its rules in time to allow testing for the festival.

While there are a fair number of Olympic athletes here, the festival generally serves more as a preview of new talent than as a showcase for established stars. This is particularly true in a post-Olympic year, a time when national teams in all sports are trying to rebuild. Of the 3,300 athletes, only 138 are Olympians.

Olympic medalists here include:

*Brisco-Hooks, who won gold medals in the 200- and 400-meter events and the 4x400 relay. She will compete in the 400, which will be run Saturday, the first day of a two-day track session.

*Calvin Smith, gold medal winner in the men's 4x100 relay and world record holder in the 100-meter dash.

*Al Joyner, gold medalist in the triple jump.

*Benita Fitzgerald Brown of Woodbridge, Va., gold medalist in the 100-meter hurdles.

*Mike Conley, silver medalist in the triple jump, who will compete in the long jump.

In diving, Louganis, the double gold medal winner, was joined by Michele Mitchell, silver medalist in platform diving.

Mitchell was in excellent form tonight as she won the three-meter springboard event with a record total of 525.78 points. Tristan Baker was second and Wendy Williamson third.

The rest of the fields are nearly strictly developmental. It is not figure-skating season, for example, and most of the champion skaters are at home working on new routines, leaving the field to juniors.

But there are exceptions. One is Debi Thomas, the No. 2 U.S. skater who is chasing America's premier skater, Tiffany Chin. But Thomas is not expected to be in top form after a long layoff.

"Possibly, she has more to lose than to gain," Thomas' trainer, Alex McGowan, said. "She's the favorite. They're all shooting at her . . . "

Two of the few feats that have escaped Louganis are scores of 800 or more in the three-meter event and 700 on the platform. He came close tonight in the springboard event as he won the gold with 693.15 points, a performance much better than expected because he has recently taken much time from training to make personal appearances and pursue an acting career.

The more important year for him is 1986 and the important event is the world championships in Madrid in July. His performance there probably will decide whether he continues to work toward the 1988 Olympics.

It can be a crucial, however, for the lesser-known athletes trying to gain recognition as they prepare for the more serious events next year. For example, Susie and Jason Dungjen moved into the lead in pairs figure skating after the short program Wednesday night when the favored couple, Gillian Wachsman and Todd Waggoner, fell twice.

"(The festival) gives the judges another chance to see us before the other competitions," Jason Dungjen said. "It helps you a lot, even if you don't place. If you just skate well, you get a little recognition just being out here."

They got their recognition here but were frustrated when Wachsman and Waggoner made an extraordinary comeback from fifth place in the free skating tonight to win the gold medal. The Dungjens finished third.

In ice dancing, the gold went to Suzy Semanick and Scott Gregory of Wilmington, Del.