Delaying school start times for middle and high school children improved the amount of sleep for adolescents and teens by an average of 29 and 45 minutes, respectively, according to a study published in Sleep.

Researchers surveyed around 28,000 students in the Cherry Creek School District in Colorado over two years and found moving school start times later in the morning resulted in increased sleep times of around 45 minutes for students, according to research published Thursday in the journal Sleep.

Middle school students went to bed an average of nine minutes later, but slept in an additional 37 minutes, giving them an average of 29 minutes of extra sleep. High school students went to bed an average of 14 minutes later, but slept for an additional 60 minutes, allowing them to sleep 46 minutes more on average.