Educators say students in an Illinois elementary school were able to focus more on learning when sitting on large exercise balls rather than chairs. Two teachers secured grant funding to provide six exercise balls for the school in March and study whether the balls help improve achievement. The program will expand to a full class in the fall. "Exercise is Miracle-Gro for the brain," said physical-education teacher Deb Surdam. "The boys and girls are sitting on these balls and using their core muscles, which starts up blood flow to the brain and helps these children focus better."