When it comes to flexibility training, there is no single “best” method. Dynamic stretching, active stretching, passive stretching, PNF (Proprioceptive Neuromuscular Facilitation), and several other techniques all have tremendous value. The key isn’t choosing one method over another, it’s understanding when and how to apply each technique based on the individual standing in front of you.

In many ways, flexibility training is similar to nutrition. People often develop strong opinions about what works best and can be hesitant to change their perspective, even as new research emerges. At AXIS, we believe the best approach is one that is grounded in science while remaining individualized to each person’s unique physiology, movement patterns, nervous system, and goals.

Your Nervous System Controls More Than You Think

One of the most fascinating aspects of human movement is the relationship between our muscles, connective tissue, and nervous system.

Every muscle fiber is wrapped in layers of connective tissue known as fascia. These layers – the endomysium, perimysium, and epimysium – not only provide structural support but also play an important role in force transmission, movement efficiency, and communication with the nervous system.

As we move and stretch, specialized sensory receptors constantly provide feedback to the brain.

  • Muscle spindles monitor changes in muscle length and help regulate how muscles respond to stretching.
  • Golgi tendon organs (GTOs) monitor tension where muscles attach to tendons and help regulate force production.

Together, these structures help determine how much movement your body allows at any given moment. Flexibility, therefore, isn’t simply about muscle length, it’s also about how your nervous system perceives and controls movement.

Why Muscle Length Matters

Now for the really interesting part. Muscles create movement through the sliding filament theory, where actin and myosin filaments bind together and slide across one another to produce force.

When a muscle remains in a shortened position for prolonged periods, those filaments have fewer optimal binding opportunities, placing the muscle in a mechanically weaker position. The same can occur when a muscle remains excessively lengthened. In either case, the muscle operates outside its ideal length-tension relationship and cannot generate force as efficiently.

Consider someone who spends much of the day sitting. Over time, the hip flexors often become chronically shortened while the hamstrings remain relatively lengthened. This altered relationship reduces the muscles’ ability to generate force efficiently and places the body in a mechanically disadvantaged position.

By restoring the hip flexors and hamstrings toward healthier functional lengths through intelligent flexibility and mobility training, muscles can operate in a stronger, more balanced, and more efficient state.

Much of this process is regulated by the nervous system, which plays a critical role in muscle tone, movement, and coordination. While this explanation simplifies a remarkably complex physiological process, it provides a practical framework for understanding why flexibility training is so important.

The Body Is Designed to Adapt

The body instinctively seeks to avoid pain. When discomfort develops, the nervous system often creates compensatory movement patterns that reduce stress on sensitive tissues. While these strategies may provide short-term relief, they frequently lead to altered biomechanics, decreased mobility, reduced force production, and inefficient movement patterns. Over time, the body can become tight, weak, and unable to perform at its physiological potential.

Fortunately, muscles and connective tissues possess remarkable adaptive capabilities.

One of these properties is known as creep, a viscoelastic characteristic of biological tissues. Soft tissues demonstrate both elasticity, the ability to return to their original length after deformation, and viscosity, the ability to gradually deform when a constant load is applied over time.

When a muscle or fascial structure is stretched, its elastic components naturally resist the change and attempt to return the tissue to its previous resting length, even if that position has become dysfunctional over time. However, when flexibility training is performed consistently with the appropriate intensity, duration, and frequency, the body gradually adapts.

Through repeated exposure to healthy movement, the nervous system becomes more accepting of new ranges of motion while connective tissues slowly remodel to support those positions. As these adaptations occur, the body begins to recognize these improved movement patterns as its new normal.

The result is improved mobility, more efficient movement, greater force production, healthier posture, and better overall musculoskeletal function.

Don’t Overlook Hydration

One factor that’s often overlooked in flexibility and mobility is hydration.

Muscles and fascia exist within a fluid-rich environment. Adequate hydration helps support the extracellular matrix surrounding our muscles and connective tissues, allowing fascial layers to glide more efficiently as we move. When we’re dehydrated, those tissues can become less compliant, contributing to stiffness, decreased movement quality, and reduced performance. Proper hydration also supports nutrient delivery, tissue repair, and the body’s ability to recover from training.

Hydration alone won’t magically improve your flexibility, but it’s an essential piece of the puzzle. Think of mobility as a recipe rather than a single ingredient. Consistent movement, intelligent flexibility training, quality sleep, proper nutrition, and adequate hydration all work together to create a body that moves more efficiently and feels better.

Applying the Science

Many of our clients come to AXIS with common postural and movement challenges, including:

  • Forward head posture
  • Rounded shoulders
  • Excessive thoracic kyphosis
  • Shortened hip flexors
  • Poor scapular control

Targeted mobility work can make a significant difference. The goal isn’t simply to become more flexible. The goal is to restore efficient movement, improve force production, reduce unnecessary stress on joints, and help the body function the way it was designed to.

That’s why flexibility training at AXIS isn’t an afterthought. It’s an essential component of helping our clients move better, feel better, and perform at their highest level, whether they’re training for sport, recovering from injury, or simply wanting to enjoy an active, healthy life.

Learn More

If you’d like to dive deeper into the neuroscience of flexibility, we highly recommend this episode of the Huberman Lab Podcast, where Dr. Andrew Huberman discusses the science behind stretching, mobility, and flexibility.

https://podcasts.apple.com/us/podcast/huberman-lab/id1545953110?i=1000773238709

Understanding the science behind flexibility allows us to program more effectively for every client we work with. Like any toolbox, success comes from knowing when to use a hammer and when to use a wrench. Every stretching technique has its place; the key is selecting the right one for the right person at the right time.