hey guys, im curious for a while ive been lifting with a split looking like this:

monday. Chest
Tuesday. BAck
Wed. shoulders
thurs. rest
Friday. Arms
Sat. Legs
Sun. Rest

ive seen some good results but feel its time to mix it up to experience new growth, my question is, is it enough to work one body part a week if your killing it or is a workout consisting of two groups a day more beneficial? Thank you.