Having difficulty with his attention span could just be the fact that he is a 6 year old boy. As far as the comment that no one carries karate forward, I have 2 friends that have started karate when they were children about this age, and to this day they both still participate. They are some of the best guys that I have ever met, oh and by the way one of them was diagnosed as a child as having ADHD and he has done great with it because they constantly keep you moving. I hope you do enroll the children in Karate because I feel that it is a worthwhile investment of time. I would also encourage you to listen to them as they get older and tell you the activities they would like to participate in.