For the study, published Wednesday in the journal Science Advances, researchers at the University of Washington monitored the sleep habits of two groups of high school sophomores. The first group was monitored in 2016 when school started at 7:50 a.m., and the other group in 2017 when classes began almost an hour later at 8:45 a.m.
Students in the latter group slept an average of 34 more minutes per night, saw their grades improve by 4.5 percent and had better attendance.
"I think I definitely felt more awake ... when I had an extra hour of sleep," Franklin High School senior Hazel Ostrowski, who participated in the study, told CBS News.
Getting a little extra sleep in the morning can be vital for teens, University of Washington professor and researcher Horacio de la Iglesia told NPR. When children reach puberty their biological clock changes, making their natural bedtime more like midnight. As a result, teens need to sleep later in the morning.
“To ask a teen to be up and alert at 7:30 a.m. is like asking an adult to be active and alert at 5:30 a.m.,” said de la Iglesia.
Despite school starting later, research found that bed times stayed relatively consistent.
The researchers noted that while students in the second group slept an average of seven hours and 24 minutes per night, they were still getting less than the recommended eight to 10 hours of sleep per night for teens.