The five girls from Rockville's Rhythmflex Gymnastics have spent an entire year working three hours a day, five days a week, to perfect the 2-minute 28-second ribbon and hoop rhythmic gymnastics routine they performed today at the Pan American Games.

The gymnasts--Katherine Betts, Stefanie Croyle, Erin Jeffress, Johanna Shoemaker and Lisa Welshinger--were not particularly happy with the way they executed their complicated choreography today (they dropped a ribbon twice and a hoop once), but they were happy with their score, which qualified them for Sunday's finals.

Rhythmic gymnastics combines elements of dance and tumbling. There are five different events--the rope, hoop, ball, clubs and ribbon. In the group competition, five gymnasts work together, interacting and exchanging the implements.

At this year's Pan Am Games, the rhythmic groups are doing two routines, one using the clubs (each gymnast has a pair of clubs) and the other using the ribbon and hoop (each group uses three ribbons and two hoops).

"You have to work together at the same time," Croyle said. "You have to predict how [your teammate's] toss is going to be. When you're an individual, you just have to worry about yourself."

The simplest distinction to make between artistic and rhythmic gymnastics is that artistic gymnasts such as Silver Spring's Dominique Dawes compete on an apparatus--such as the balance beam or uneven parallel bars--while rhythmic gymnasts compete with an apparatus--such as the ribbon or hoop.

"People always ask if we know Dominique Moceanu," Croyle said. "But that's like asking a swimmer if she knows the synchronized swimmers. It's a different sport."

Rhythmflex is one of the few gyms in the country that specializes in rhythmic gymnastics. "There's usually a gym in every town that has artistic gymnastics," said Alicia Albe, who works with the group at Rhythmflex and also is a U.S. assistant coach at the Pan Am Games. "You're lucky to find one gym that does rhythmic gymnastics in a state."

Croyle, 16, moved from Boston to Rockville with her family to train at Rhythmflex. Betts was invited to train at Rhythmflex, so she moved from Syracuse, N.Y. Betts and Welshinger, whose family is in Minnesota, live with the Jeffress family in Rockville.

All five attend area high schools--Jeffress, Betts and Welshinger go to Rockville High, Croyle goes to Sandy Spring Friends School and Shoemaker goes to Wootton--but leave school at 12:30 each afternoon to go to the gym. They practice five hours a day.

"Repetition is the key," Albe said. "Repetition, over and over. We work for a long time on these routines. With five gymnasts working together, there's a lot to worry about. Sometimes four might be in a good mood, and one might not."

Kate Jeffress, Erin's older sister, is competing as an individual here. She qualified for Sunday's finals with a total score of 37.364, which put her in fifth place. Preliminary scores do not carry over into the finals.

Kate Jeffress worked in a group for about a month last year, when one of the group members was injured. She had two weeks to learn the routine, which she was able to do because of her experience and skill, before the group competed at the national and world championships. Now she's back focusing on her individual routines.

"I like doing both," Kate Jeffress said. "But I can't do both. It's impossible; there's no time. If you're going to be good at one, you have to focus on either one or the other."