What is a Stretch?

Stretching: What Are We Actually Changing?

The story of stretching hasn’t changed much over the years and remains a relatively simple idea. A muscle feels tight, we stretch it, the tissue lengthens and the body moves better. Problem solved. It’s tidy, logical and the idea of fluidity and bendiness sells as an intuitive counter to stiffness and ageing. Maybe too tidy!

I need to start by stating that this is not an argument against stretching. I’ve been accused in the past of being “anti-yoga”, when in reality I’m not anti-anything in terms of movement practices.

The question isn’t whether stretching is good or bad, or whether we should or shouldn’t do it. The question is what we think is happening when we stretch, compared with what is probably happening physiologically.

The Old Story

The traditional explanation has tended to be that tight muscles are short muscles. And if muscles are short, they need lengthening so stretching becomes the logical mechanical correction.

There may indeed be situations where tissue properties change over time, especially with repeated exposure. However, the common clinical leap from “this feels tight” to “this tissue is short” is generally way too quick. Stretching may change range, but that does not mean that a muscle has been permanently lengthened.

Weppler and Magnusson (2010) argue that increases in range after stretching may be explained less by mechanical lengthening and more by changes in sensation. In other words, people may tolerate more stretch before the sensation becomes uncomfortable.

“Tight” Is an Experience

When someone says, “I feel tight,” they are reporting a sensation or experience rather than offering a direct measurement of tissue length. Feeling tight can have a lot of reasons behind it but at the end of the day is mostly perception. Tissue isn’t irrelevant, but sensation isn’t always automatically structural.

For therapists and movement teachers this is important. The language we use has power over what people believe about their bodies. If every feeling of tightness is described as a short muscle, stuck fascia or blocked tissue, the client may start to see their body as a collection of defective parts that need fixing.

Flexibility is not a moral virtue

Somewhere along the way, flexibility, like posture, became confused with health. The more flexible person is often assumed to be healthier, whereas the stiffer person is presented as restricted or perhaps ageing badly.

But being able to fold forwards, sit in a deep squat, or place a foot behind the head may be impressive, but not automatically useful or healthy. A ballet dancer or, gymnast may need large ranges, but for other people, the question is whether they have enough range for the life they actually live.

Older adults may need the confidence to get down to the floor and back up again. A gardener may need hip range for kneeling and squatting. A manual therapist may need comfortable rotation, reach and endurance. A runner, however, is unlikely to need the hip range of a contortionist.

The false war of mobility versus stability

Mobility and stability are often presented as opposites, as though the body must choose between being free or being controlled. In reality, good function always requires degrees of both.

Too little mobility can make movement narrow and guarded. Too little stability can make loaded movement unreliable or uncontrolled. The aim is not to worship either, but to understand what a person needs to do and where that need is being challenged. The proportions will vary depending on the task.

We can consider stability as synonymous with strength, but there is a persistent idea that strength training will reduce flexibility. Afonso et al. (2021) however, found that strength training can improve range of motion and may be comparable to stretching in some contexts. This should not be surprising. Strength brings options to movement that might otherwise be limited by experience, pain or lack of control. Loading a painful or restricted area (with no damage present) to make it stronger, often yields remarkable results where stretching has failed. Range without control is just more space to get lost in.

Stretch Tolerance: The nervous system at end range

When someone improves their range after stretching, mechanical length may be involved, but just as likely is the nervous system is allowing the someone to move further before the sensation is interpreted as too much, referred to as stretch tolerance. This is not an “all in the head” idea but simply says that sensation, protection and movement are part of the same system.

At end range, the body is receiving information from muscle, tendon, joint, skin, fascia-rich tissues and free nerve endings, with all of this is being interpreted in context.

Have I done this before? Is this position familiar? Is it threatening? Is it painful? Am I safe? Can I get back out again?

Repeated exposure may change the answer to many of those questions. Through repetition, the person learns that they can go into and return from this position safely. Range increases as confidence and tolerance grows.

Context also includes what is coming next. A session of stretching followed by a warm bath and massage is one thing. Static or prolonged stretching before sports where speed or power are needed may be another. Behm et al. (2016) suggest that stretching needs to be understood in relation to task and timing. Stretching is rarely wrong, it’s just not a universal tool.

The Golgi Tendon Organ Story

Another common narrative is that the Golgi tendon organs, or GTOs, detect tension and switch the muscle off. While this explanation is not a complete invention, it is often taught far too mechanically.

The Golgi tendon organs are sensory receptors associated with tendon and muscle tension. They contribute to the nervous system’s understanding of force and load, but aren’t emergency buttons that instantly release a muscle because we held a stretch for long enough.

A better explanation is that stretching may alter the nervous system’s response to a position. It may change tolerance, perceived threat, muscle tone, movement confidence and GTOs are a part of this, but not the whole explanation.

MITER: Movement in and through extended range

This is where I think we need a more useful practical model, and I’ve coined the term MITER: movement in and through extended range.

The point of MITER is not to force more range, but instead to explore whatever extended range is currently available, even slightly, and then moving through it.

The person may bump up against a stretch sensation, but they do not need to camp there or fight with it. They simply visit the edge, keep moving, and allow the system to experience range as part of movement rather than as an end point.

The speed is dependent on the person but is generally slow. For some, extended range might be a small shoulder reach. For others, it might be a deeper lunge, loaded squat, or dance-specific position. The size of the range matters less than their relationship to it.

MITER simply changes the emphasis. Instead of asking, “How far can I stretch this tissue?” we ask, “Can I move into this range, through this range and out of this range with awareness, control and enough ease?”

That brings stretching back into movement, where it belongs.

Keeping the practice, updating the story

Stretching is not nonsense. Yoga isn’t pointless and increasing flexibility can be important for many people. But some of the explanations around these practices are overdue an update. Yoga poses, no matter how long you hold them for, will not ‘release fascia’.

From my perspective, the aim is to have enough movement options for the life, work, sport or art someone needs or wants to be part of.

Sometimes that will involve stretching, at other times resistance or strength training. Sometimes it will involve rest, graded exposure, better pacing or simply moving more often in more varied ways.

Flexibility is an option but function is always the point.

References

Afonso, J., Ramirez-Campillo, R., Moscão, J., Rocha, T., Zacca, R., Martins, A., Milheiro, A.A., Ferreira, J., Sarmento, H. and Clemente, F.M. (2021) ‘Strength training versus stretching for improving range of motion: a systematic review and meta-analysis’,Healthcare, 9(4), 427.

Behm, D.G., Blazevich, A.J., Kay, A.D. and McHugh, M. (2016) ‘Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review’,Applied Physiology, Nutrition, and Metabolism, 41(1), pp. 1–11.

Warneke, K. et al. (2025) ‘Practical recommendations on stretching exercise’,Journal of Sport and Health Science.

Weppler, C.H. and Magnusson, S.P. (2010) ‘Increasing muscle extensibility: a matter of increasing length or modifying sensation?’,Physical Therapy, 90(3), pp. 438–449.