Georgia Chiropractic Neurology Center

Brain Based Treatment for the 21st Century!

Written by Sophie Hose, DC, MS, DACNB, CCSP

Imagine you are at the gym, lifting weights for the first time. You feel the burn, the exhilaration, and the satisfaction of pushing your limits. Over the weeks, something remarkable happens—you are getting stronger. But how does this transformation occur? From a chiropractic neurology standpoint, your body’s journey to strength involves more than just muscles; it is a complex interplay between your nervous system and physical training. Let’s dive into the fascinating process of how your body builds strength, starting with muscle hypertrophy and progressing to the critical role of your nervous system.

What Is Muscle Hypertrophy?

Muscle hypertrophy refers to the growth of muscle fibers due to resistance training or other forms of physical stress. When you challenge your muscles through activities like lifting weights, tiny tears occur in the muscle fibers. Your body’s repair process, driven by protein synthesis, not only fixes these tears but also reinforces the muscle, making it thicker and stronger. Over time, consistent training increases the size of individual muscle fibers, resulting in larger, more capable muscles.

Hypertrophy can be broken into two types:

  1. Myofibrillar Hypertrophy – This involves an increase in the size and number of myofibrils, the contractile proteins within muscle fibers. It enhances the muscle’s ability to generate force, directly contributing to strength.
  2. Sarcoplasmic Hypertrophy – This involves an increase in the volume of the sarcoplasmic fluid surrounding the myofibrils. While this type primarily improves muscular endurance and size, it plays a supporting role in overall strength gains by improving the muscle’s capacity to sustain repeated efforts.

This process is closely tied to strength gains. Larger muscles have more contractile proteins, enabling them to generate greater force. However, it is important to note that hypertrophy is not the sole driver of strength—especially in the early stages of training. Here, the nervous system takes center stage.

The Nervous System: Strength’s Unsung Hero

While muscle hypertrophy contributes to long-term strength increases, the initial gains you experience when starting a training program are largely due to changes in your nervous system. These neural adaptations pave the way for better communication between your brain, spinal cord, and muscles, enabling you to lift heavier weights even before your muscles grow significantly.

Neural Adaptations in Detail

     1.Improved Motor Unit Recruitment

Muscles are made up of motor units—a motor neuron and the muscle fibers it controls. When you perform a movement, your nervous system recruits motor units to generate force. Initially, only a small number of motor units may be activated, but with training, your brain becomes more efficient at recruiting more motor units, particularly the larger ones responsible for high force production.

For example, when performing a heavy squat, your nervous system gradually learns to recruit motor units that control fast-twitch muscle fibers, which are capable of generating greater force compared to slow-twitch fibers.

     2.Increased Firing Rate

The firing rate refers to how quickly motor neurons send signals to muscle fibers. A higher firing rate translates to more rapid and forceful muscle contractions. Resistance training trains your nervous system to increase this firing rate, enhancing your strength output. This adaptation is especially crucial for explosive movements like sprinting or Olympic lifts.

     3.Improved Intermuscular Coordination

Strength isn’t just about isolated muscles working harder; it is also about how well different muscles work together. Resistance training helps improve intermuscular coordination, ensuring that agonists, antagonists, and stabilizers work in harmony during complex movements like squats or deadlifts. This synergy boosts overall performance and reduces the risk of injury.

For instance, during a bench press, the chest, shoulders, and triceps must work together, while stabilizers like the rotator cuff ensure the movement is controlled. Neural adaptations optimize this coordination, allowing for smoother and more efficient movement patterns.

     4.Reduced Neural Inhibition

Your body has built-in safety mechanisms to prevent excessive force that could cause injury. These mechanisms, such as the Golgi tendon organs, inhibit muscle activation when they sense high tension. Training gradually reduces this inhibition, allowing you to generate more force safely.

This reduction in neural inhibition is particularly noticeable in heavy resistance training, where the nervous system becomes more tolerant of higher levels of muscle tension.

The Role of Sensory Feedback in Strength Training

Your nervous system does not just send signals to muscles; it also relies on feedback from sensory receptors to refine movement and maximize strength. Proprioceptors, like muscle spindles and Golgi tendon organs, provide real-time information about muscle length, tension, and joint position. This feedback loop allows your brain to fine-tune motor output, improving both strength and coordination.

Additionally, resistance training enhances the sensitivity of these proprioceptors. Over time, this heightened sensory input helps you execute movements with greater precision and efficiency. For instance, proprioceptive improvements can lead to better balance during a single-leg squat or enhanced stability during a deadlift.

The Mind-Muscle Connection

Another fascinating aspect of the nervous system’s role in strength training is the mind-muscle connection. This refers to the conscious effort to engage specific muscles during a movement. Studies have shown that focusing on the muscle being worked increases neural activation, leading to better recruitment of motor units.

For example, when performing a bicep curl, actively thinking about contracting the biceps can enhance the effectiveness of the exercise, promoting both strength and hypertrophy over time.

Long-Term Adaptations: The Intersection of Neurology and Hypertrophy

As you progress in your training, the balance between neural and muscular adaptations shifts. While neural changes dominate the initial stages, hypertrophy plays a more significant role in long-term strength gains. Interestingly, these two processes aren’t isolated; they interact in ways that amplify their effects.

For example, a more efficient nervous system can activate larger portions of your hypertrophied muscle fibers, maximizing force production. Conversely, larger muscles provide a greater foundation for the nervous system to exert its influence. This synergy underscores the importance of combining neural and muscular adaptations for optimal strength development.

Moreover, advanced lifters often experience a plateau in strength gains due to the diminishing returns of neural adaptations. To overcome this, strategies like periodization and advanced training techniques (e.g., cluster sets or accommodating resistance) are employed to further challenge both the nervous system and muscle tissue.

Practical Tips for Maximizing Strength Gains

  1. Progressive Overload: Gradually increase the weight, repetitions, or intensity of your exercises to continually challenge both your muscles and nervous system.
  2. Variety in Training: Incorporate different types of resistance training—such as heavy lifting, explosive movements, and endurance-based exercises—to target various neural and muscular adaptations.
  3. Focus on Technique: Proper form ensures that neural pathways are reinforced correctly, minimizing the risk of injury and maximizing efficiency.
  4. Prioritize Recovery: Adequate sleep, nutrition, and rest allow your nervous system and muscles to recover and adapt effectively.
  5. Engage in Mindful Practice: Develop a strong mind-muscle connection to optimize neural activation and muscle engagement during workouts.
  6. Include Mobility Work: Improved joint mobility enhances proprioceptive feedback, allowing for more effective and controlled movements.

The Science of Periodization

Periodization is a systematic approach to training that involves varying intensity, volume, and exercise selection over time. This strategy not only prevents overtraining but also ensures continuous progress by targeting different neural and muscular adaptations. A typical periodization model includes phases such as:

  • Hypertrophy Phase: Focuses on increasing muscle size through higher volume and moderate intensity.
  • Strength Phase: Emphasizes neural adaptations with lower volume and higher intensity.
  • Power Phase: Combines neural efficiency with muscular force production through explosive movements.

Conclusion

Strength is more than just a measure of muscle size; it is a testament to the intricate relationship between your nervous system and physical training. By understanding and harnessing this connection, you can unlock your full potential and achieve lasting improvements in performance. Whether you are a beginner or an experienced athlete, remember that every rep, set, and moment of effort contributes to a journey that is as neurological as it is muscular.

If you or someone you love could be benefitting from physical activity or you have any questions on how you might want to modify activities to be able to do them safely, contact the team at Georgia Chiropractic Neurology Center today. We look  forward to hearing from you.

Peer-Reviewed Sources:

  1. Enoka, R. M., & Duchateau, J. (2017). Translating neural control of movement to high performance athletics. Journal of Sports Medicine, 47(3), 119–131. doi:10.1007/ s40279-017-0757-0
  2. Aagaard, P., & Andersen, J. L. (2010). Effects of strength training on endurance capacity in top-level endurance athletes. Scandinavian Journal of Medicine & Science in Sports, 20(2), 39–47. doi:10.1111/j.1600-0838.2010.01197.x
  3. Folland, J. P., & Williams, A. G. (2007). The adaptations to strength training: Morphological and neurological contributions to increased strength. Sports Medicine, 37(2), 145–168.doi:10.2165/00007256-200737020-00004
  4. Gabriel, D. A., Kamen, G., & Frost, G. (2006). Neural adaptations to resistive exercise: Mechanisms and recommendations for training practices. Sports Medicine, 36(2), 133–149.doi:10.2165/00007256-200636020-00004