A University of Minnesota study has confirmed what South Washington County school officials were banking on when they agreed to push back high school start times in 2009: Students who get at least eight hours of sleep are better prepared to learn.
Performances on state standardized math tests rose at the district's high schools — as did average daily attendance — following the move from 7:35 to 8:35 a.m. starts, said university researcher Kyla Wahlstrom.
However, according to the study, there were no significant changes in state reading test results.
Wahlstrom presented the findings to school board members in December.
There was a point of concern for district leaders in the generally favorable report: 88.5 percent of students surveyed at South Washington County's three high schools reported having a cellphone in their bedrooms.
Simply activating the light on a phone "has the potential for significant disruption of sleep," Wahlstrom told board members.
South Washington County Superintendent Keith Jacobus said he believed parents should take note of how cellphones can affect sleep. It was perhaps best, he said, to be away from electronic devices for about an hour before bedtime.
For nearly 20 years, Wahlstrom has studied how school start times affect students. She has pushed for later start times for high schoolers, in particular, because she says the teenage brain develops differently than an adult or prepubescent brain.
