REDWOOD CITY — On the blacktop at Clifford School recently, a fourth-grade class played two-on-two keep-away with basketballs. Jessica Mazeau, a physical education instructor who teaches at Clifford five days a week, led the students in dribbling and passing drills.

She does not actually work for the school or for the Redwood City School District. The school’s parent-teacher organization pays $71,000 a year to Rhythm and Moves, a company based in Burlingame, which sends Mazeau to the school along with sports equipment including hula hoops, jump ropes and basketballs.

Clifford has its own physical education teacher for students in grades six through eight, but none for younger students. Parents fear that without Rhythm and Moves there would be no physical education instruction for kindergarten to fifth grade.

“Clearly, if we don’t fund it the kids are not getting any activity outside, except for minimum recess time and lunch time,” said Marilyn Ezrin, co-president of the Clifford School Parent-Teacher Organization.

But experts say such efforts are a symptom of how physical education has become a luxury as California schools have cut budgets.

The state requires students in grades one through six to receive 200 minutes of physical education every 10 school days. Schools in Redwood City have struggled for years to meet that mandate. Statewide, it is fairly common for younger students to receive less physical education than the state requires, said Doug Jann, education programs consultant for the California Department of Education.

The Redwood City School District’s budget for physical education has shrunk with the state budget crisis, leaving fewer than nine positions in the subject for all 16 schools in the district, which borders two towns where some of the wealthiest people in Silicon Valley live.

It employs no physical education teachers who instruct younger students and has not done so for many years, according to Naomi Hunter, a district spokeswoman. Responsibility for teaching physical education to younger students falls to the classroom teachers, who may not have the same enthusiasm for the subject as for math or reading.

A patchwork approach to teaching physical education to younger students has emerged throughout the district, relying on parents to donate time and money, as well as support from foundations and nonprofit organizations.

“We have found creative ways to make sure that students are getting P.E.,” said John Baker, deputy superintendent for the district.

But that is not good enough for many health experts.

“It’s a Band-Aid,” said Drisha Leggitt, executive director of the California Association for Health, Physical Education, Recreation and Dance, a nonprofit organization. “Let’s say the parent-teacher organization had a bad year, or the parent volunteer’s kid moved into a different school. What happens with the P.E. program?”

At seven schools in the district, coaches from Peninsula Community Center, a fitness club, teach weekly sessions of sports like basketball, volleyball, Frisbee and soccer while classroom teachers observe from the sidelines.

Serve the Peninsula, a nonprofit in Redwood City that supports public schools, created the program three years ago. It now costs about $160,000 annually, supported by the Sequoia Healthcare District, which receives its financing through property taxes.