SEATTLE (AP) — More school districts around the U.S. are heeding the advice of scientists who have long said that expecting teens to show up to class before 8 a.m. isn't good for their health or their report cards.

The Seattle school board voted last month to adopt an 8:45 a.m. start time beginning next year for all of its high schools and most of its middle schools. Seattle is joining 70 districts across the nation who adopted a later start time in recent years.

The movement still has a long way to go: There are more than 24,000 U.S. high schools. Supporters expect that such decisions will be made more quickly now that people have mostly stopped debating the underlying science.