Enlarge By John Moore, Getty Images The number of states that allow students to waive or substitute physical education classes has grown despite rising rates of childhood obesity. OBESITY COMPLICATIONS OBESITY COMPLICATIONS DES MOINES  When the Des Moines school district announced this fall it was going to make it tougher for students to waive their physical education classes by scaling back all but a handful of exemptions, it caught students and parents by surprise. It also countered a national trend. Despite growing concerns about obesity among young people, the number of states that allow students to waive or substitute physical education classes has grown from 27 to 32 since 2006, according to Paula Kun, a spokeswoman for the National Association for Sport and Physical Education (NASPE). OBESITY TASK FORCE: Michelle Obama reveals goals CHILDHOOD OBESITY: Oregon slimmest state, Mississippi largest According to an association report in June, students in those states can skip physical education if they enroll in interscholastic sports, marching band, cheerleading or other activities. The number of states that allow waivers for health issues, disabilities or religious reasons has risen from 18 to 30 since 2006, according to the report. NASPE opposes waivers or exemptions from physical education classes, Kun says. "Unfortunately, so many schools are having more and more waivers — particularly at the high school level," Kun says. "The great majority of high school students are required to take physical education only one year out of the four. They get out for religious reasons, for ROTC, for marching band. There's a whole slew of waiver possibilities." The increase in waivers stems from a push for students to take more courses and efforts within school districts to save money, says Stephen Jefferies, a Central Washington University professor of physical education and public health. Some schools offer online physical education, NASPE President Lynn Couturier says. The online courses combine study about health and nutrition with exercise students do on their own. The changes in Des Moines were made to bring the district into compliance with state regulations, says Elaine Watkins-Miller, a spokeswoman for the Iowa Department of Education. Iowa law requires students to take physical education all four years of high school, although school boards can grant waivers for students in interscholastic athletics. At the district's Roosevelt High School, the change affected up to 100 families, Roosevelt Principal Kathie Danielson says. Waivers should be limited to upperclassmen who need them so they can complete all their graduation requirements, says Carol Greta, a lawyer for the Iowa Department of Education. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more