CHICAGO (CBS) — A  new Illinois law eases rules regarding how often schools need to offer physical education classes. Teachers are fighting it.

Illinois was the first state in the nation to mandate daily P.E. But in August a new law eased that mandate, making it easier for schools to cut PE.

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Bridget Shanahan of the Illinois Education Association, which represents teachers and other school workers, says that will affect the physical and academic health of students.

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“P.E. helps students focus more on the arts or music or the core classes,” she says. “It improves brain function and helps pump oxygen into the brain.”

The IEA has launched a campaign, including a television commercial, in support of daily P.E.

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But supporters of the new law say P.E. was an unfunded mandate, and some school districts claim they lack the facilities and staff to offer daily P.E.