Fitness enthusiasts and bodybuilders train hard in pursuit of sculpted boulder shoulders, which are seen as a sign of strength. The deltoids — shoulder muscles that help in arm movement and stabilize the shoulder joint — enhance the much-craved ‘V-taper’ (a term used to describe a physique consisting of broad, wide back and shoulders with a narrow waist, creating a V-shaped appearance). However, these muscles often seem difficult to grow. Their mystique not only lies in their striking appearance, but also in the intricate science that governs their development.
“Deltoid muscles are found in the upper shoulder,” says Dr Dilip Chand Raja, consultant, bone, joint and spine surgeon, Raja Superspeciality Clinic, Chennai. “They are the least used upper limb muscles in day-to-day activities, as they only become active when people do overhead tasks.”
Difference between deltoids and the rotator cuff
The deltoid muscles, also referred to as the delts, are a group of three distinct muscle heads that form the bulk of the shoulder muscles. They contain both red and white muscle fibers.
Beneath the deltoids, there are many other muscles, like the rotator cuff, which also stabilizes the shoulder joint. “The deltoid is not a single muscle; it has many parts: the anterior, posterior and medial heads. These three different parts need to be trained in three different directions,” says Dr Raja.
Unlike the deltoid muscles, the rotator cuff’s primary function is to keep the head of the upper arm bone (humerus) secure within the shallow socket of the shoulder (glenoid). The rotator cuff initiates a wide range of shoulder movements while preventing dislocations and injuries. It also plays a pivotal role in maintaining shoulder joint health, especially during activities that involve repetitive overhead motions, like throwing or lifting.
Why are deltoids difficult to grow?
The importance of the shoulder joint cannot be overstated, and the development of the delts is closely linked to the health of the rotator cuff.
“The rotator cuff muscles [supraspinatus, infraspinatus, teres minor and subscapularis], also known as the SITS muscles, surround the shoulder muscles. When we apply excessive load to the deltoid unevenly or move with incorrect form, the rotator cuff gets injured, which stops the person from training the deltoids,” says Dr Raja.
Uneven load, bad form and lifting too heavy too soon can strain the rotator cuff. “Whenever the rotator cuff gets strained, the SITS muscles get atrophied,” adds Dr Raja. “Due to this, the initiation of movement of the deltoid muscles becomes difficult.”
If you want to do an overhead press or bench press, the initial movement comes from the rotator cuff. When your rotator cuff is not working properly, you will not be able to load the delts effectively, and they will not grow. “The ability of the deltoid muscle fibers to convert from slow twitch to fast twitch and vice versa is low,” adds Dr Raja. This also plays a part in their growth.
How to grow delts effectively
To grow the deltoids effectively, the principle of progression is key. The focus should be on strengthening the whole shoulder complex.
People these days want to buff up their shoulders and see that nice contour of the deltoids. This depends on how progressively they are loading that muscle to get the hypertrophy required.
“Execution or form is important,” says Wanitha Ashok, a Fit India ambassador and fitness expert from Bengaluru. “While exercising, you can’t just swing your hands when you are lowering them or bringing them down towards gravity; it should be a controlled movement. Your muscles should do the work, not the momentum.”
The progression and frequency of loading matter rather than how much you load. “It is recommended to first bring flexibility to your shoulder and strengthen your rotator cuff muscles. Once your range of movement in all directions is pain-free, you can train your deltoid muscles,” says Dr Raja.
Shoulder presses are the standard exercise; when done repeatedly, they have been shown to increase the size of the muscle. The key is to be slow and take it step by step. You need to do six to eight exercises for each head of the shoulder.
Apart from this, performing exercises like shoulder abduction, lateral raises and straight arm rows under the guidance of a trainer is also beneficial. The trainer can modify the exercises as per one’s fitness level.
“To effectively grow the deltoids, one can include isolation and compound exercises. Side and front raises as well as shoulder presses are examples of isolation exercises. Wall push-ups, floor push-ups and triceps dips are compound exercises that also engage the shoulder muscles,” explains Ashok.
- Deltoids, found in the upper shoulders, help in arm movement and stabilize the shoulder joint.
- When excessive load is applied to the deltoids unevenly or one moves with incorrect form, the rotator cuff gets injured, which stops the person from training the deltoids.
- The principle of progression is key to growing the deltoids effectively. It’s not about how much you load, but how progressively and frequently it is done.