With four boys I consider it vital to give them breaks. However, I've found that they don't have to be long. Often times 5-10 minutes is enough. They might swing, climb the tree, or work on a Lego or other project. The 8yo has more breaks than the 11yo, but he really needs it as he is just more active. On average, I'd say that the 8yo takes 3-4 short breaks and the 11yo 1-2.