The Centers for Disease Control and Prevention and the U.S. Department of Education have both come to the conclusion that students have been saying for ages: schools start too early.

While experts recommend that adolescents get at least eight and a half hours of sleep a night, a joint survey by the two agencies released Thursday revealed that over 80 percent of U.S. middle and high schools start their first class too early to get that kind of rest, according to Fox News.

The study found that only 17.7 percent of U.S. middle and high schools start at 8:30 a.m. or later, preventing students from getting the 8.5 to 9.5 hours of sleep they need.

Depriving teens of those precious hours of sleep puts their academic performance at serious risk, the CDC said in its Morbidity and Morality Weekly Report, according to Yahoo! News.

"Getting enough sleep is important for students' health, safety, and academic performance," said Anne Wheaton, lead author and epidemiologist in CDC's Division of Population Health.

Researchers also warned that the effects dont' just impact their performance in school and can have adverse effects outside school, according to Newser. 

"Insufficient sleep is common among high school students and is associated with several health risks such as being overweight, drinking alcohol, smoking tobacco and using drugs," the CDC found.

Parents, in the past, have urged schools to delay start times, but administrators often refused, citing that such a change would make it too difficult to organize after-school extracurricular activities.

A 2013 study found that about two-thirds of U.S. middle and high school students are sleep deprived.

The study authors recommend that school districts start school at later times. Parents and health care providers can also help their kids get more sleep by establishing a consistent bedtime and rising time throughout the week.