More than 82% of public middle and high schools start too early for students to be healthy, says CDC

Public middle schools and high schools in many states start too early for students to get the necessary amount of required sleep to be healthy, says a study released on Friday by the Centers for Disease Control and Prevention. The study says, "Adolescents who do not get enough sleep are more likely to be overweight; not engage in daily physical activity; suffer from depressive symptoms; engage in unhealthy risk behaviors such as drinking, smoking tobacco and using illicit drugs; and perform poorly in school."

"Among an estimated 39,700 U.S. public middle, high and combined schools (with an estimated total enrollment of 26.3 million students), the average start time was 8:03 a.m.," the study found. The study, which recommends schools start no earlier than 8:30 a.m., found that only Alaska (8:33 a.m.) and North Dakota (8:31 a.m.) have average start times later than 8:30 a.m. Overall, only 17.7 percent of the 39,700 schools start after 8:30 a.m. (CDC map: School start times before 8:30 a.m.)

Several schools have average start times earlier than 8 a.m.: Alabama, Colorado, Connecticut, Delaware, Indiana, Louisiana, Maine, Massachusetts, Michigan, Mississippi, Missouri, Nevada, New Hampshire, New York, Ohio, Pennsylvania, Rhode Island, Tennessee, West Virginia, Wisconsin and Wyoming. Louisiana's average start time of 7:40 a.m. is the earliest, and 29.9 percent of the state's public schools start before 7:30 a.m.

CDC recommends that adolescents get nine hours of sleep per night, Christopher Ingraham reports for The Washington Post. "They need all that extra sleep to support their still-developing brains. But surveys consistently show that only about eight or nine percent of teens are getting that much sleep. Because teens' brains are naturally wired to keep them up past 11 p.m. or so, starting the school day later is essentially a requirement for allowing most of them to get adequate sleep."