Only six states nationwide require the recommended 150 minutes of elementary school-based physical education, according to a study by University of Georgia kinesiology professor Bryan McCullick.
Two states require adequate physical education instruction in middle school, but no states do so for high school students. Guidelines are set by the National Association of Sport and Physical Education.
McCullick's study examined the role of federal courts in interpreting ambiguous physical education statues.
While public health reforms have emphasized school-based physical education as a means of combatting the childhood obesity epidemic, the study's results found that courts typically do not interfere with state legislative decisions concerning curriculum.
"Findings indicated that statutes were written in a manner that did not explicitly mandate school-based physical education but rather recommended or suggested it," McCullick wrote in his report, which was published in the June issue of the Journal of Teaching in Physical Education.
Many schools are reducing or eliminating their physical education programs due to budget cuts, combined with a greater emphasis on academic performance.
According to McCullick, a lack of firm requirements reduces the likelihood that schools will adhere to the guidelines.
Generally, American high school courses last about 50 minutes per period, totaling just 250 hours of physical education coursework per week. Schools would exceed the recommended 225-minute guideline if states required four credits of physical education courses, but no states do so.
New Jersey boasts the strongest requirement of all states, mandating 3.75 credits of physical education for graduation, or about 187.5 minutes per week. But the number still falls 37.5 minutes short of the guideline.
In Iowa, the state's statute required that physical education be taught in elementary schools, but did not specify how often and included the ambiguous wording "pupils in kindergarten through grade five shall engage in physical activity for a minimum of 30 minutes each school day."
According to McCullick, since physical activity can take many forms and does not a require a specialist, Iowa school officials would technically be adhering to the statue if they allowed students 30 minutes of recess each day.
That said, "Recess does not guarantee 30 minutes of moderate to vigorous physical activity," McCullick said. "Unfortunately, many legislators and school officials think the opposite."
The U.S. Department of Health and Human Services recommends that children and adolescents should engage in at least 60 minutes of physical activity daily. A 2009 survey found that only 18 percent of high school students adhered to this recommendation, while only 33 percent attended physical education class each day.