Can You Change The Shape Of Your Muscles?

Summary

In this insightful conversation, Dr. Mike and Dr. Brad Shonfeld explore the concept of regional hypertrophy in muscle growth. They discuss the possibility of differential muscle development within a single muscle head and along the length of a muscle. Dr. Shonfeld, a leading expert in muscle hypertrophy, shares compelling evidence supporting the existence of regional hypertrophy, influenced by factors like eccentric and concentric training. The discussion delves into the practical implications for bodybuilders and fitness enthusiasts, suggesting that targeted training can subtly alter muscle appearance and shape, enhancing the understanding of muscle development for optimized training programs.

Takeaways

• 💪 Regional hypertrophy refers to the growth of specific parts of a muscle, either between different muscle heads or along the length of a muscle.
• 🏋️‍♂️ Muscle fibers do not always span from origin to insertion; some terminate within the fascicle, which can lead to nonuniform muscle growth.
• 🧠 The concept of regional hypertrophy goes against traditional exercise science teachings, which stated that muscles develop uniformly from proximal to distal ends.
• 🔬 Evidence suggests that eccentric training can lead to greater growth at the distal portion of a muscle, while concentric training shows greater growth in the middle.
• 📊 There is compelling evidence supporting the idea that regional hypertrophy can be achieved through different types of training.
• 🤔 The long-term effects and visibility of regional hypertrophy on the macro scale, such as in bodybuilding, are still areas of uncertainty in the literature.
• 🏋️‍♀️ While you cannot change the inherent shape of a muscle (e.g., from flat to peak), you can influence the overall body shape by targeting specific areas of muscle growth.
• 🦿 Medialateral hypertrophy differences within a single muscle head have not been shown, unlike proximodistal differences.
• 🦵 The position of the feet and hands, as well as elbow and knee tracking, can influence which parts of a muscle are emphasized during training.
• 📚 A study in review suggests that single-joint exercises like leg extensions can target specific heads of the quadriceps differently than multi-joint exercises like leg presses.
• 🦶 For the calves, seated calf raises do not selectively target the soleus more than the gastrocnemius, contrary to common belief.

Q & A

What is regional hypertrophy and what does it refer to?

Regional hypertrophy refers to the concept where different parts of a muscle can grow at different rates, either between different muscle heads or along the length of a single muscle. It can also refer to the differential growth in response to specific types of training.

Is there evidence to support the idea of regional hypertrophy along the length of a muscle?

Yes, there is compelling evidence suggesting that regional hypertrophy along the length of a muscle is possible. Studies have shown that certain types of training, such as eccentric training, can lead to greater growth at the distal portion of the muscle.

Can muscle fibers span from origin to insertion in all muscles?

No, not all muscle fibers span from origin to insertion. Many muscles have fibers that terminate intrafascicularly, meaning they do not necessarily span the entire length from one end to the other.

How do different types of training affect regional hypertrophy?

Different types of training, such as eccentric and concentric actions, can have varying effects on regional hypertrophy. Eccentric training has been shown to promote more growth at the distal end of the muscle, while concentric training can lead to more growth in the middle aspect.

What is the magnitude of difference in muscle growth due to regional hypertrophy?

The magnitude of difference in muscle growth due to regional hypertrophy can be significant, with some studies showing more than a 10% difference in growth between different regions of the muscle.

Can regional hypertrophy be observed on a macro scale, like in physiques?

While regional hypertrophy can be observed with tools like ultrasound or MRI, its visibility on a macro scale, such as in physiques, may not be as noticeable unless one looks closely or there is a significant difference.

Can foot and hand positions during exercises affect regional hypertrophy?

Yes, foot and hand positions can influence which parts of the muscle are targeted, potentially leading to regional hypertrophy differences. For example, turning toes in or out during calf raises can emphasize different aspects of the gastrocnemius muscle.

What is the impact of different squat stances on muscle hypertrophy?

Different squat stances, such as a sumo wide stance, can lead to greater activation of certain muscle groups. For instance, a wider stance can work the adductors and glutes to a greater extent compared to a narrower stance.

How does the type of exercise (single joint vs. multi-joint) affect muscle hypertrophy?

Single joint exercises, like leg extensions, can target specific muscle heads more effectively, such as the rectus femoris, while multi-joint exercises, like leg presses, can work on different muscle heads, like the vastus lateralis.

What are the practical implications of understanding regional hypertrophy for muscle training?

Understanding regional hypertrophy allows trainers and athletes to design more targeted training programs that can potentially alter the shape and appearance of muscles, even though the inherent shape given by genetics cannot be changed.

Is there any research on the effectiveness of seated calf raises compared to other calf exercises?

Research suggests that seated calf raises do not selectively target the soleus muscle more than the gastrocnemius, contrary to popular belief. Both muscles experience similar growth with seated calf raises, which is less than what is achieved with straight leg raises.