This confusion stems from a lack of effective training methods. Many bodybuilders make the mistake of believing the delts receive enough heavy work from bench presses and barbell
rows; therefore, they feel the need to concentrate on "refining" the delts with exercise; such as lateral and bent-over raises. Since these movements isolate the sinews of the
shoulder, lighter weights are in order, as are higher reps if sufficient stress is to be placed on them. This method works well in theory, but real-world results often belie the
effectiveness of the best plans. Light work may bring out detail, but for truly massive shoulders, you have to go heavy! Using heavy weights for shoulder training, however, can
prove to be a problem. The delts, rotator cuff and infraspinatus are all areas prone to injury. Once damage occurs, it seems to take for-ever to heal.
Unlike other muscles, the deltoids are packed into a small area from which they push (anterior deltoid), pull (posterior deltoid), and raise the arms to the sides (medial deltoid). No matter what movement you make with your arms, whether it be lifting weights or going about your daily tasks, the delts will receive a certain amount of activation. Naturally, normal usage, regardless of how exhausting it may be, won't promote growth. For that, you have to thrash those babies hard to force them beyond their accustomed ways and make them really work.
You can't obtain any growth in the delts until you experience deep muscle ache. But don't make the mistake of confusing fatigue with ache. This sensation is common with light-weight movements like lateral raises. Because the shoulders are fibrous and sinewy, even if you merely hold your arms up at your sides, they'll tire easily. The tiny fibers, incapable of negligible growth, will begin to hurt. Rotating your arms in small circles will cause them to burn and fatigue after a minute or so, but that doesn't mean it will produce growth. They're just tired. Because of the complex functioning of this bunch of bowl-like muscle fibers and tendons, higher reps work very well for bringing out definition, but if you're looking for more mass, you have to get that ache.
A way around the dilemma of deltoid-training is called the halfway press. It works the delts deeply without excessive strain. You can do the halfway press with dumbbells or a barbell, in front of or behind the neck, hands forward or facing each other, seated or standing. You can even use it with various machines. It works especially well with the Smith machine.
Despite all the esoteric shoulder movements available, presses are still the best exercise for packing on mass. The halfway press is simply an ordinary pressing movement that works within the strongest range of motion in the middle of the movement. In the midrange the meat of the muscles comes into play, and that's what you must stress in order to obtain sufficient overload to induce growth. Keeping the range of motion short achieves this objective perfectly. Also, by staying within a limited range, you protect the shoulder joints from the stress of repetitive motion which causes abrasion to the rotator cuff.
Start the movement with a little cheat to get the weight above your head. The beginning of a press is the part where the shoulders are most compromised and susceptible to injury. That's why one naturally heaves a weight up using some momentum when going heavy. Press in the normal manner, stopping short of lockout. This point is very important! Whenever you lock out, you remove the stress from the deltoids and shift it to the bones of the arms and wrist. There's a certain psychological satisfaction to jamming the elbows tight at the end of a press. It signifies completion, finality, accomplishment. Unfortunately none of those effects has anything to do with working the deltoids.
Slowly lower the weight until your hands are level with your ears, concentrating on keeping continuous tension on the delts. Repeat the movement, maintaining steady contraction as you raise the weight. The entire range of motion will be about 12 inches up and down. Don't stop until you experience that ache in the muscle bellies of the delts. You won't have to wonder what it feels like - you'll know when it happens!
Make the halfway press the sole exercise for your shoulders the next time you train them. Complete 6 to 10 sets, taking each set to failure. You'll be amazed how a half-movement can produce such good results, but that's just what halfway presses will do as long as you put your best effort into them. Stick with heavy halfway presses for your next six shoulder workouts and you should see a major improvement in your delt development. Make them work. Make them ache. Watch them grow.