The medics might be right, but all that disorders enumerated turn to nothing against the so many things that you gain from kendo. Besides, every medal has its reverse. But I would say I consider that medicine less due to story, happened to my friend. Once he had been seriously bad after trial. Doctors did miracle saving him, and said therefore that he ain't have much time to live. He tryed that time much to keep him better. And when he found kendo, it was like second breath for his organizm. He is very active player for now. The next time medics wondering he's still alive, he smiles in return. That is the way kendo is.