I'm training on a 3X5 Rep System at the moment, so this question does not affect me directly. I'm just curious. The perceived wisdom seems to be that regularly(every Big Three Lift)training heavy Singles quickly leads to burn out for all but the most elite athletes. So would regularly working up to a Double be safer, since by defination it would be lighter than a Single? Or would it still be too heavy for week in, week out training?