u should definatley not train them ED or EOD. even if u have really good genetics u shouldn't do this if your goal is to get your back wider. alot of people dont realize that when they train they are actually breaking down muscle tissue. thats why u need to let them rest so they can recover and get stronger and larger. u said that a while back u used to to do pushups and grew an awesome chest as a result. well, im sure when u were younger you had better recovery ability but regardless i bet if u would have done a more conventional approach to training your chest they would have been even more impressive. so remember, stimulate the muscle, then let it rest so it can adapt to the stress and grow