The cross country team may do more for your child's grades than the math tutor. Robert Brown/iStockphoto hide caption toggle caption Robert Brown/iStockphoto Shots - Health News Want Your Kids To Ace School? Good Motor Skills May Help June 19, 2014 Children and teenagers who are aerobically fit and and have good motor skills do better academically, researchers say. But muscle strength doesn't help. And those motor skills may matter most.