I have been told by a few psychiatrists and psychologists that ADD and ADHD is hereditary. I knew I had ADD, now my yongest son has it. We are very much alike. Very physical people.
I bike when I can, run 2-3 days per week. At the end of my work day, I have a excess energy that I need to get rid of. Running and biking help alot. It also gives me time to put my day in order without distractions.