Your shoulders do a fair amount of work whenever you perform back and chest exercises, but performing exercises that single out your delts are also important for the following reasons:
Strong shoulders make most arm movements easier, whether you’re throwing a baseball, passing food across the table, or lifting a suitcase that’s a little too heavy. Virtually every upper-body exercise involves your shoulder muscles to some extent, so strengthening your shoulders enables you to lift heavier weights for chest and back exercises.
If your shoulders are weak, they’re going to take a beating even if you perform chest and back exercises perfectly. Shoulder exercises also can prevent weekend warrior–type injuries, such as a torn rotator cuff from a softball tournament, or slapping a puck into the garbage can that serves as your hockey goal. If your shoulders are weak, you can even injure yourself doing day to day choirs.
Open up any bodybuilding magazine / social media account and you see headlines such as, “Delts to Die For” or “Sexy, Strong Shoulders.” Bodybuilders take their shoulder training seriously because they know that these muscles play a big part in their appearance, which, after all, is what bodybuilding is all about.