interesting read i found a while back, cant search for it but ill explain what it summarized.. you can do what your doing ceo, with the chest/shoulder day.. no problem with that... but if you train chest after a shoulder day, or shoulders after a chest day then that is a terrible idea.. Your shoulders really get sore 6-8 hours after your workout, so they need 24-48 hours of rest, but when doing them similatenously with another bp that incorporates shoulders (chest) then it's ok, because they dont begin to get sore until 6-8 hours after.. Ever notice, no matter, how hardcore you go with shoulders you wont feel sore after a workout, but sore the next day??