Philip Kang, a sixth-grader at Arlington's Tuckahoe Elementary School, can give you several reasons why he loves the "cool" new rock-climbing wall in the gym, but there is one in particular: "No rope burns," he said, holding up his hands.

Forget rope climbing, the old-fashioned way of building upper-body strength in children. Rock-climbing walls are being installed at seven Arlington elementary schools to get students to exercise those muscles -- and restore the good name of physical education.

PE has become anathema to many children in a generation with a 25 percent obesity rate, and schools are going to some lengths -- and heights -- to make exercise more attractive. Arlington's new walls are so "in" that the students' older siblings even go rock climbing on dates.

Area school districts, including Anne Arundel and Stafford counties, have introduced the walls, borrowing the idea from similar ones at some outdoor clothing stores and commercial climbing gyms.

"All teachers are trying to engage kids to enjoy learning, and they need to do that in the case of physical activity, too," said Judy Young, executive director of the Reston-based National Association for Sport and Physical Education. After only a few weeks, the evidence in Arlington suggests the wall is working.

"They love it," said Bruce Keith, a physical education instructor at Tuckahoe. "Physical education is not the favorite subject for a lot of kids." But after the wall was introduced, Keith said, one parent told him, " 'My kid talked about physical education for the first time.' "

PE's popularity has waned as many children raised on the fast-paced entertainment of video games and television find it tedious or even humiliating. "You had the kids who felt intimidated when you had the team-type sports and they would lose," Keith said. "And then you had them doing the same things over and over again, the jumping jacks, the sit-ups, the stretching routines."

There was no boredom in the rapt faces of his sixth-graders as he showed them how to use the wall on a recent Friday morning.

Students took turns, looking like little sand crabs as they reached for the various rock-shaped plastic handles, called "commercial holds," and stretched and grasped their way across nine plywood panels, each more difficult than the last.

Behind the climbers, classmates "spotted" them -- holding up their arms, ready to help balance anyone who tottered. The wall is more horizontal than vertical -- 8 feet high and 32 feet long -- so the children move mostly across rather than up and don't need a safety harness.

Jennifer Frias, 10, was one of the risk-takers, starting right in on the hardest panel. "I like a challenge," she said confidently, adding that the activities that make up the usual PE fare, jumping rope and monkey bars, "aren't hard for me."

Classmates Emily Willard, Andrew Richards, Thomas Trapnell and Kang took turns spotting each other, and Richards said he liked the camaraderie of the exercise. "Even if you're not friends," he said, "you're going to be friends once you get on the wall."

Jim Garrett, a recreational therapist and owner of Elements to Excellence Inc., a company that installs walls at schools and other facilities, said the walls also give children a chance to test coordination, balance and flexibility.

And much of the exercise is mental, Garrett said, comparing it to chess as the students calculate which move to make next.

"It is challenging," he said. "But when they finish, there is a sense of accomplishment. They say, 'Look at me. I've climbed higher than I ever have before.' " He particularly likes the combination of individual achievement with the cooperation of spotting, much like team sports.

Garrett said the brightly colored holds, which can be adjusted at various levels, have a special attraction. "The kids really flip out over the wall -- they love to run up to it and touch it," he said.

The walls are joining other less traditional activities such as in-line skating and aerobics as part of the mainstream physical education curriculum. "These kinds of activities didn't even exist 30 years ago," Young said, adding that the goal is to make them a habit for a lifetime.

Meanwhile, the wall's reputation is getting around. Deborah C. DeFranco, Arlington schools' supervisor for health, physical education and athletics, said the district hopes to install more of them, at $4,000 apiece. What surprises and pleases her most about the walls is the way special-needs students have taken to them.

"They normally don't get to participate in other activities," she said.

And then there are the grown-ups. At a recent training session on safety techniques, a group of Arlington physical education teachers puffed and perspired their way across the wall.

"It looks easy, but . . . I can feel it in my arms," instructor Janet Marco said, adding, "I'll have to get in practice before I teach them. Otherwise, they would think I was human."

Fifth-grader Jennifer Frias focuses on her handhold as she scales the new climbing wall at Tuckahoe Elementary School in Arlington. The wall is longer than it is tall, to minimize the danger of falls.Students "spot" their classmates, positioning themselves to assist any unsteady climbers. Rock climbing has joined in-line skating and other activities as schools try to modernize PE.