When it comes to growing your deltoids (delts), understanding the anatomy and fibre orientation is crucial. Many people make the mistake of focusing solely on the lateral head of the deltoid, thinking that it’s the key to big, round shoulders. However, it’s essential to recognize that the anterior (front) and posterior (rear) delts contribute significantly to shoulder width and size.
Table of Contents
Understanding Deltoid Anatomy
The deltoid muscle consists of three heads: anterior, lateral, and posterior. The lateral head, responsible for abduction of the shoulder, is often the most targeted. However, it’s relatively small compared to the anterior and posterior heads. The key takeaway is that for bigger, more developed shoulders, you need to emphasize both the anterior and posterior delts.
The posterior delts, in particular, are often undertrained. They play a crucial role in shoulder aesthetics and overall upper body strength, especially for a balanced physique. Many athletes and gym-goers neglect this muscle group or train it ineffectively. Mastering the posterior delts can dramatically improve shoulder development.
The Best Exercises for Rear Delts
The information for this article is largely based on a video shared by Ryan Humiston. His YouTube channel has become one of the fastest-growing fitness channels out there with close to 2 million subscribers and more than 230 million video views.
Full and Partial Range of Motion
When training for hypertrophy, the rear delts benefit significantly from a full range of motion. However, another effective approach is partial reps at longer muscle lengths. The reason for this is rooted in muscle physiology – training muscles in stretched positions has been shown to elicit hypertrophy, according to recent research. Therefore, performing rear delt exercises at the longer muscle lengths can be highly effective.
Isolation and Movement Pattern Control
One of the challenges with rear delt training is isolation. Many rear delt exercises involve secondary muscles like the traps and lats, which can hinder the effectiveness of the workout. For example, exercises where the shoulder is abducted horizontally tend to engage the traps, while movements involving shoulder adduction may activate the lats.
To target the rear delts effectively, focus on movement patterns that minimize the involvement of other muscles. Two strategies work well here: performing exercises that prioritize scapular protraction (rather than elevation) and controlling the range of motion to prevent other muscles from taking over.
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Ranking Rear Delt Exercises
Let’s go through some common rear delt exercises and rank them based on effectiveness:
1. Machine Rear Delt Fly
- Rating: D
- The standard rear delt fly on a machine often allows the traps to take over, making it less effective. By simply grabbing higher on the handles, the exercise improves slightly (D+), but it still fails to isolate the rear delts effectively.
2. Sideways Unilateral Rear Delt Fly (on Machine)
- Rating: B
- Sitting sideways on the machine can dramatically improve the movement’s effectiveness. This position puts the rear delts in a stretched position and forces you to control the movement more precisely, reducing trap involvement.
3. Lying Incline Rear Delt Fly
- Rating: S
- Lying on an incline bench with arms closer to the body during rear delt flies is one of the best exercises for this muscle. The biomechanics here favor the posterior delts over the traps or lats, and the movement mimics the natural line of action of the rear delts.
4. Dual Cable Rear Delt Fly (Arms Close to Body)
- Rating: S
- Another top-tier exercise is the dual cable variation where the arms stay close to the body. This constant tension exercise allows you to fine-tune the angle to maximize rear delt engagement while minimizing trap involvement.
5. Single Arm Cable Rear Delt Partial ROM
- Rating: S
- If you could only do one rear delt exercise for the rest of your life, this would be a strong contender. It focuses on the stretch position of the muscle, isolates the rear delt effectively, and allows for controlled overload, making it the best rear delt movement in many lifters’ opinions.
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The Science of Rear Delt Training
Why do exercises like the lying incline rear delt fly and single-arm cable rear delt fly work so well? The answer lies in the biomechanics of muscle action. The posterior delts have a horizontal pull when the arms are in flexion, giving them a better mechanical advantage for certain movements compared to larger muscles like the lats.
This is due to the concept of internal moment arms, which consider the insertion points and the line of pull for each muscle. For instance, in a straight-arm movement, the posterior delts can generate more torque than the lats, despite the latter being a larger muscle group. Understanding this principle can drastically change how you approach rear delt training, emphasizing proper movement patterns and focusing on effective load distribution.
Bonus Tip: Training with Longer Muscle Lengths
Training at longer muscle lengths is another highly effective strategy for hypertrophy. As your range of motion increases, your traps inevitably engage more due to the body’s natural scapular-humeral rhythm. To counter this, focus on lengthened partials, ensuring that you’re still isolating the rear delts even as you near the end of your range of motion.
A Quick Word on Recovery
Injury prevention and recovery are just as important as the exercises themselves. Utilizing advanced recovery techniques, such as stem cell therapy, local injections like BPC-157, and red light therapy, can help speed up healing after muscle injuries. These strategies are especially useful when dealing with injuries to critical muscles like the calves, which play a significant role in overall movement patterns. However, always talk to your doctor before trying something new to your body.
Final Thoughts
Rear delts are one of the most underdeveloped areas for many athletes, but with the right exercises and a deeper understanding of their anatomy and biomechanics, you can transform your shoulder development. Focus on isolation, control your movements, and leverage the science behind muscle action to maximize your gains. By incorporating exercises like the single-arm cable rear delt fly and the lying incline rear delt raise, you can build bigger, stronger, and more balanced shoulders.
Key Takeaways:
| Key Point | Details |
|---|---|
| Prioritize Posterior Delts | Focus on rear delts for shoulder width and aesthetics |
| Top Exercise | Lying incline rear delt fly for best isolation |
| Training Method | Use lengthened partials to engage rear delts without traps taking over |
| Isolation Importance | Minimize secondary muscle involvement (e.g., traps and lats) |
| Recovery | Utilize advanced techniques like stem cell therapy for faster healing |
