"The single most powerful tool we have to improve the function of the brain is exercise," states Dr. John Ratey of the Harvard Medical School. Ratey and Carroll School have joined forces to examine the effect of exercise on our student population. Ratey's book, "Spark," was read widely by the faculty this summer, and we all returned to faculty meetings in August with an hour of exercise before listening to Ratey describe how exercise opens up the brain for learning. In concert with the Harvard School of Public Health, we are collecting evidence of the impact of early morning exercise on student progress. The faculty is also adding movement and exercise components to their educational programs in fascinating ways. Over the course of the school year, Dr. Ratey will return several times to help us analyze our progress. Questions abound: Should we change the whole school schedule to place exercise as the first period for all students? How much exercise makes how much difference? Does the length of time between exercise and the learning task matter? How can we combine exercise with traditional, essential learning objectives?