Blog Post #1 Stretching Debunked

When we think about improving flexibility, it’s easy to assume that stretching physically lengthens our muscles. However, recent research shows that flexibility is more about how your nervous system adapts than how your muscles stretch. Here’s a look at how this process works.

Stretch Tolerance: Your Nervous System’s Green Light

Stretching improves range of motion (ROM) by enhancing "stretch tolerance"—your nervous system’s ability to allow movement without interpreting it as pain or risk.

A study in The Journal of Applied Physiology found that repeated stretching increased ROM, not by lengthening muscle fibers but by improving participants' comfort in stretched positions. The nervous system became more accepting of the new range, making stretches feel less uncomfortable over time.

Reducing Neural Inhibition

Your nervous system naturally protects your muscles through neural inhibition, limiting how far they can stretch to prevent injury. Regular stretching appears to reduce this inhibition, particularly by calming the stretch reflex—a mechanism that causes muscles to contract when stretched too far.

Research in Sports Medicine suggests that consistent stretching retrains these reflexes, helping your body allow deeper stretches without triggering protective responses.

Training Proprioceptors

Proprioceptors, like muscle spindles and Golgi tendon organs, play a key role in monitoring muscle length and tension. Stretching seems to "desensitize" these sensors, making them less likely to signal contraction when muscles are stretched.

Over time, this adaptation allows muscles to move farther without resistance, contributing to improved ROM. Golgi tendon organs also assist by promoting muscle relaxation during prolonged stretching, though their role in flexibility is still being studied.

The Role of the Brain

Flexibility isn’t just about your muscles; it’s also about your brain. Your central nervous system (CNS) processes signals from stretched muscles and decides how far you can safely go.

With regular stretching, the brain learns to interpret greater ROM as safe, reducing discomfort and pain signals. Studies suggest that flexibility gains may be partly psychological, with the CNS adapting to the stretching experience.

Muscles Aren’t Actually “Getting Longer”

Contrary to popular belief, static stretching doesn’t significantly change muscle length or structure. A study in The Scandinavian Journal of Medicine & Science in Sports found that muscle stiffness and length remained largely unchanged after a stretching program, while increased ROM was linked to improved stretch tolerance.

Takeaway: Flexibility is Neuromuscular

Flexibility training is less about "lengthening" muscles and more about teaching your nervous system to feel safe and comfortable with greater ROM. By reducing neural inhibition, calming reflexes, and improving stretch tolerance, stretching helps you move farther with ease.

This perspective shifts the focus of flexibility training, offering a more effective and sustainable way to approach stretching—by working with your nervous system, not just your muscles.