"Can I grow my inner pecs?" - Biasing muscles and regional hypertrpohy
Oct 29, 2023
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The podcast explores biasing muscle divisions and regional hypertrophy. They discuss how bias influences muscle activation, growth patterns of muscles in different areas, and challenges of targeting specific muscle heads. The impact of antagonist inhibition on muscle growth is explored, focusing on muscles like biceps, triceps, and hamstrings. The influence of joint position on hamstring activation and the concept of region hypertrophy are discussed. The podcast also explores regional variations in muscle fiber types, genetics and muscle growth, and the importance of stabilization for muscle activation. The hosts delve into building inner pecs in the chest muscles and the debate around regional hypertrophy. They also discuss the importance of shoulder position for triceps muscle activation, the intricacies of the lats, and the significance of antagonist inhibition and the two joint muscle principle in muscle growth. The podcast concludes with a discussion on volume counting, growing inner pecs, and upcoming topics on physiological modeling and failure types.
Regional hypertrophy and bias are terms commonly used in exercise discussions, and they have distinct differences.
Bias in exercise refers to the deliberate emphasis placed on specific muscle fibers or regions during a movement.
Regional hypertrophy is influenced by factors like neuro-mechanical matching, two-joint muscle principles, and mechanical tension due to the length-tension relationship within muscles.
Two-joint muscles often display variations in growth along their length, influenced by factors like neuro-mechanical matching, sarcomere elongation, and activation ratios of motor units.
Understanding the impact of leverage and resistance profiles can help design training programs to target specific muscles and optimize muscle activation.
Deep dives
Regional hypertrophy and bias in exercise terms
Regional hypertrophy and bias are terms commonly used in exercise discussions. Regional hypertrophy refers to the growth of specific regions within a muscle group, while bias refers to the activation and emphasis placed on certain muscle fibers or regions during exercises. These terms are often used interchangeably but have some distinct differences. Regional hypertrophy is influenced by factors like neuro-mechanical matching, two-joint muscle principles, and mechanical tension due to the length-tension relationship within muscles. Exercise selection plays a role in regional hypertrophy, where different exercises can target specific muscle regions. However, factors like genetics and individual muscle fiber types also contribute to the variations in regional hypertrophy.
Understanding Bias and Neuro-Mechanical Matching
Bias in exercise refers to the deliberate emphasis placed on specific muscle fibers or regions during a movement. Often, bias is achieved through neuro-mechanical matching, where certain exercises activate and recruit specific motor units based on joint positions. This matching process occurs in two-joint muscles, which are muscles that span more than one joint. As joint angles and positions change, the activation and contribution of different muscle regions within a two-joint muscle may vary. For example, changing foot rotation in calf exercises can affect the activation of different regions within the calf muscles. Understanding bias and neuro-mechanical matching can help in designing effective exercise programs that target specific muscle regions.
Factors Influencing Regional Hypertrophy
Regional hypertrophy can be influenced by a combination of factors. One significant factor is the sarcomere length and strain within specific regions of a muscle. Sarcomeres that undergo greater elongation in response to exercise can result in region-specific hypertrophy. Exercise selection and mechanics also play a role, as certain exercises put more tension and stress on particular regions of a muscle, leading to localized growth. However, individual genetics and the proportion of fast-twitch or slow-twitch muscle fibers can also contribute to differences in regional hypertrophy. While exercise selection can target specific regions, the overall growth of muscle groups depends on various factors, including genetics and training techniques.
Proximal-Distal Growth and Two-Joint Muscles
Two-joint muscles, those that span more than one joint, often display variations in growth along their length, ranging from proximal to distal regions. The growth patterns of these muscles are influenced by factors like neuro-mechanical matching, sarcomere elongation, and activation ratios of motor units. These variations in growth are functional and specific to the demands placed on the muscle during movement. For example, calf muscles can display differences in activation and growth based on foot position and tibial rotation, while hamstring muscles can be influenced by hip and knee joint angles. Understanding the interplay of mechanics and muscle activation can inform exercise selection and help achieve targeted growth in specific regions of these two-joint muscles.
Importance of Training with Your Genetic Predisposition
When it comes to training, genetics can play a role but it is important to focus on what you can control. If you are primarily a slow-twitch muscle fiber person, training for explosive athleticism may not be effective. You should work with what you have and make the best of it, rather than worrying about genetics. Ultimately, consistent and intelligent training will lead to progress and maximize your potential.
Abs and Their Training
Training abs is often a topic of discussion, but the reality is that building strong abs doesn't require complex exercises or excessive training. Doing simple exercises like crunches and focusing on spinal flexion and core bracing can effectively work your abs. While stabilization exercises like ab wheel rollouts exist, they are not necessary for overall ab development. The key is to reduce body fat to reveal your abs and give them the definition you want.
Understanding and Building Different Regions of Pectoral Muscles
Building the inner and outer pecs is a common goal, but it is important to understand that regional hypertrophy is complex and still not fully understood. While there may be some potential for regional growth, it primarily comes down to overall muscle development and body fat reduction. A variety of exercises, such as incline dumbbell curls, barbell curls, and preacher curls, can help target different areas of the pecs. However, the key is consistent training with good exercises to achieve maximal growth.
Understanding the Two-Joint Muscle Principle
Two-joint muscles, such as the hamstrings and biceps, cannot effectively perform both of their actions simultaneously. When a muscle has leverage to produce antagonistic joint actions, it gets switched off in favor of more efficient muscle activation. For example, hamstring muscles are not efficiently engaged in hip extension during a squat because they also produce knee flexion. This principle applies to various muscle groups across different joints, and understanding it is crucial for effective training.
The Importance of Leverage and Resistance Profile in Muscle Activation
The leverage and resistance profile of an exercise significantly affect muscle activation. For instance, in lat exercises like pull-downs, the 45-degree range of motion before full shoulder flexion enables optimal recruitment of the lat muscles instead of the biceps. Additionally, using horizontal shrug variations engages the traps more effectively than vertical shrugs, as the horizontal position allows for greater loading without relying heavily on other muscle groups. Understanding the impact of leverage and resistance profiles can help design training programs to target specific muscles and optimize muscle activation.
