D.C. students would have to complete more art, music and physical education before they can graduate under a proposal by the DC State Board of Education. But school leaders warn that the new requirements would hurt both students who excel and those who lag behind.

In a letter to the DC State Board of Education, DC Public Schools Chancellor Kaya Henderson and the heads of seven major public charter schools also criticized the proposal to increase the total number of required credits from 24 to 26 — among the highest in the nation — to mandate that students log 225 minutes of physical activity a week and to require a senior thesis.