So now I am one year into training and have followed the following split for most of the year - Chest/Tri/Calves, Back/Bi/Abs, Rest, Shoulder/Traps/Calves, Legs/Abs, Rest and Repeat.

I have noticed now that Chest and Arms are significantly smaller than I would like them to be. I want to begin doing more Chest days and incorporating Arm days, and spend less time on legs and shoulders. My question is how often should I train legs and shoulders to avoid them losing muscle mass? I am quiet proud of the progress I have made with them and would hate to see them get smaller. I was thinking once every ten days or so rather than once every six days. Is this a good idea? Or does anyone have a recommended split for me to use to enhance my chest and arms?