All of this concentrated learning — activities parents commonly think of as enrichment — was taking place not after school hours, but during recess, the once-unstructured midday break that for some elementary school students is slowly being squeezed out of the day. Jump rope, freeze tag and the jungle gym have some new competition. At some of the city’s highest-rated public elementary schools, recess is now being seen by parents and educators as a time to pack in extra learning. Free time during school hours has become a hot topic among educators across the country, many of whom worry that children are not getting enough of it. Recent studies, including one published in 2009 in the medical journal Pediatrics, indicate that many children learn better and behave better when free time is part of the school day. The New York City Department of Education does not require recess, although its Wellness Policy recommends that schools provide 20 minutes a day, preferably outdoors. Nonetheless, the practice of packing enrichment classes into recess has become increasingly common at some of the city’s top-performing elementary schools, where parents see them as a way to fill gaps left by years of budget cuts and an increasing emphasis on standardized tests. The parents at P.S. 188 — where class size can peak at 32 — are taking the approach that their children, who earn some of the best test scores in the city, need enrichment classes as much as they need free time. To that end, the school’s PTA, which operates out of a converted bathroom on the first floor, raised $12,500 last year to support voluntary clubs, which meet once or twice a week at lunchtime and offer subjects that include art, music and computers. Janet Caraisco, the principal at P.S. 188, has been fitting all of the clubs’ activities into her school’s schedule. “We do a lot of it at recess,” she said. “It’s not easy. But we think it’s important.” Ms. Caraisco herself runs several book clubs and a musical theater club. Last year, one of her clubs spent weeks engaged in a dramatic reading of the script for Disney’s “Beauty and the Beast,” with students and principal occasionally belting out lyrics in the principal’s neat but bustling office. For the most part, each of the school’s clubs has as many as 14 or 15 members; some students join as many as four. At P.S. 6, a highly regarded school on the Upper East Side, students can design video games, build miniature roller coasters, learn about electrical circuits and perfect magic tricks at PTA-sponsored recess clubs. “It’s a lot of little options, hobby-type stuff geared toward introducing kids to different things,” said Steve Tosi, whose son James attends first grade there. Down the street at P.S. 290, lunch clubs allow students to learn improvisational performance, make comic books, learn sign language and knit. And at P.S. 372 in Brooklyn, an arts-focused school where special education students learn alongside other students, fourth- and fifth-grade lunch club members can choose from an array including mosaic designing, mural making and embroidery. The school also offers chorus and dance. Parents say lunchtime clubs give children a chance to learn in a setting more intimate than the typical classroom, and lets them spend time with like-minded students. “They’re coming from these classrooms of 30 kids,” said Nick Gottlieb, PTA co-president at P.S. 3 in Greenwich Village, where educators run a popular lunchtime program that pairs students with adult volunteers, who read and discuss books with them. “It’s quiet, individualized time,” Mr. Gottlieb said. Principals say they work hard to keep students from becoming overwhelmed by recess club options. Ms. Caraisco, for example, does not send lunch club forms home, so students can choose for themselves how they want to spend that time. “We’ve had times when a parent really wants a child to do a club that the child really doesn’t want,” she said. She also sends students to the schoolyard during her weekly book club, if it is clear they are fidgety and need some time to run around. That did not seem to be the case during a recent meeting of the school’s computer club, where a pack of lively fourth graders was developing eight-page travel brochures. Their teacher, Steven David, showed them how to search for data, historical information and pictures. But what about recess? Elizabeth Katanov, 9, in jeans and a peace-sign T-shirt, said she was delighted to have extra time to work on computer skills with her friends. On the screen in front of her was a colorful rendition of the Florida state seal. “It’s definitely worth it,” she said, “especially on bad winter days when you’d have to go outdoors.”