The nondescript concrete building sits hard by unused railroad tracks that separate it from a cemetery.

It is in this highly unglamorous setting, at the end of a cul de sac and flanked by industrial warehouses and garages at the Glendale-Los Angeles border, that the Verdugo Gymnastics Center inconspicuously attends to the business of producing and refining athletic skills.

The youngsters who roll into the 6,500-square-foot building for instruction tumble out with a first-rate gymnastics education.

"I remember when I walked in here for the first time, I thought, 'This is real gymnastics,' " said David Hesbon, 32, a coach at the center who is a nationally rated judge and a former member of the U. S. National Junior Team.

"They're not just doing forward and backward rolls in here."

Indeed, more than 200 athletes test and extend their limits under the watchful eyes of an experienced staff.

Flags and ropes hang from the ceiling and mats cover the floor. One wall is mirrored and others are adorned with posters showing world-renowned gymnasts.

From an upstairs area overlooking the main floor, parents and other spectators can watch the gymnasts practice their routines.

During peak hours, the center is a flurry of tumbling and twisting activity.

As many as 100 students will be practicing at a time, rotating from station to station.

"There are no events (apparatus) empty," Hesbon said. "If something is abandoned, it's only that way for about a minute until someone else snatches it up."

Founded in 1973, the center has been designated by the United States Gymnastics Federation as a national training center--one of only three in Southern California and the only one in Los Angeles County.

Classes are offered for aspiring gymnasts of all levels, from toddlers to adults.

"We're trying to provide a safe environment for people to learn," said Brenda Browning, 27, a coach and the center's managing director.

"Schools aren't doing as much physical fitness as they used to. This gives kids a place to develop friendships and get physically fit."

\o7 Kindernastics \f7 are offered to help children ages 22 months to 4 1/2 years develop body awareness, coordination, rhythm and perceptual motor skills.

Beginner and intermediate classes incorporate an introduction to the various events of men's and women's competitions.

Introductory, intermediate and advanced teams compete in local, regional and national competitions.