I have begun to incorporate 2 a day splits into my program a while back. At first I trained a different muscle group in the morning than I did in the evening(Ex: morning chest, evening back). However, recently I have been training the same bodypart during both workouts(Ex:deltoids, biceps, triceps work in both workouts, but different exercises(lifts) in each. And by saying different exercises, I dont mean different parts of the same group(Ex:front deltoids one workout and rear deltoids in another), I mean hitting all parts of whatever group I am working twice.
Assuming that I am correct in saying it's more productive to hit the same group 2x in the 2 a day split. My question is whether it would be more productive to hit all parts of the muscle group twice(Ex:front, side, rear deltoids all in both workouts) or to split it into maybe doing front deltoid in the morning whilst hitting side and rear deltoids at night.
Forgive me for all the (Ex:) bullshit, just trying to make what im trying to ask clear and not confusing.