Washington, Feb 17 (IANS): About half of the parents in the US support later school timings for their teenagers, shows a survey.

The University of Michigan C.S. Mott Children's Hospital National Poll on Children's Health was conducted in November/December 2014, following last year's recommendation from the American Academy of Paediatrics (AAP) that middle and high schools start at 8:30 a.m. or later.

Among the national sample of parents with teenagers aged 13-17, 40 percent parents expect a later start to allow their teenagers to get more sleep and 22 percent think it would improve their school performance.

Meanwhile, others worried about how later start times would affect schedules and logistics, with one in five parents saying a delayed start would not allow enough time for after school activities and 1 in 7 expecting the change to negatively affect transportation issues.

Twenty-seven percent of parents said they would only support the later time if it didn't impact school budgets while 24 percent would support the change regardless.

"Teenagers are chronically sleep-deprived and that can negatively impact their health and well being," said Matthew Davis, director of the National Poll on Children's Health and professor of paediatrics at the University of Michigan Medical School.

"We know teens are biologically wired to have later sleep cycles, which has raised the question of whether school start times that align to adolescent's natural sleep rhythms could help improve health outcomes," Davis said.