One of the biggest differences between the bodybuilding legends of the 1970s and ’80s compared with today’s is the relative size of the delts. You cannot be successful in modern competitive bodybuilding without large delts. There may be more leeway in classic physique classes, but for straight up bodybuilding, shoulders must be prioritized to develop the “look” of a 21st century bodybuilder. The shoulders are composed of three distinct heads: the front (anterior), side (medial), and rear (posterior). The best exercise for isolating the side delt is lateral dumbbell raises. This is performed starting with the arms extended (but not straight) down at your sides. Keeping your arms extended, raise the dumbbells directly out to the sides, palms facing down, until at or just below shoulder level (the body forming a T). Then keeping arms stiff, lower the dumbbells back to the starting position, stopping just short of straight down in order to keep tension on the muscle.
It’s a good practice to raise the dumbbells with the pinkie up. This forces the arm to stay internally rotated, keeping the load on the side delt rather than the front delt. If you find yourself wanting to bend your arms and raise the dumbbells above shoulder level, lighten it up, straighten out the arms, and keep your pinkies up.
ALTERNATIVE
Machine side-delt raise.
FORM AND FUNCTION
The medial delt arises from the superior surface of the acromion process and inserts at the deltoid tuberosity of humerus. The medial delt laterally abducts the upper arm.
