Everyone wants delts like Phil Heath, but if you don’t have the genetics to build boulder shoulders, we now have scientific proof showing which exercises are best for getting—and keeping—them. 

Researchers wanted to record the EMG activity of the three portions of the deltoid (anterior, middle, and posterior) in eight different exercises. Subjects performed the free-weight bench press, Smith machine shoulder press, pec deck, reverse pec deck, free-weight lateral raise, cable-crossover lateral raise, incline lat pulldown, and seated row. Here’s a breakdown of the most effective exercises.

ANTERIOR DELTOID

EMG activity of the anterior deltoid did not differ significantly between Smith machine shoulder press, free-weight bench press, or pec deck. However, the researchers found that muscle activation of the front deltoid was greater in the Smith machine shoulder press than in the free-weight lateral raise, cable-crossover lateral raise, reverse pec deck, seated row, or incline lat pulldown.

MIDDLE DELTOID

The researchers noted that the EMG activity of the middle deltoid did not differ significantly among the free-weight lateral raise, cable-crossover lateral raise, reverse pec deck, or seated row. They reported that the free-weight lateral raise resulted in greater EMG activity of the middle deltoid than the shoulder press, incline lateral pulldown, bench press, or pec deck.

POSTERIOR DELTOID

According to the researchers, the EMG activity of the posterior deltoid was greatest during the reverse pec deck, incline lat pulldown, and seated row, and did not differ significantly among these exercises. They also reported that the reverse pec deck resulted in greater activation than the cable-crossover lateral raise, free-weight lateral raise, bench press, shoulder press, or pec deck.

To sum it all up, the research concluded that it’s best to use several different exercises to build impressive shoulders. The best exercises for the anterior deltoid were: the Smith machine shoulder press, free-weight bench press, and pec deck. The best exercises for the middle deltoid were: the free-weight lateral raise, cable-crossover lateral raise, and reverse pec deck. For the posterior deltoid, the best exercises were: the reverse pec deck, incline lat pulldown, and seated row. – FLEX