People often talk about needing to “be more flexible” but actually have a hard time verbalizing what that really means, or what they really want. Often, what the average person really wants is to feel less stiff in their daily life and have more range of motion, either in general or during exercise.
Here’s the harsh reality: stretching does not make you more flexible. This has been shown in meta-analysis (reviews of multiple studies) – traditional static stretching done in typical clinical or training environments does very little to make lasting changes to a person’s flexibility.
This seems counterintuitive to everything we’ve learned since being in grade school PE classes, right?! But, like everything we do here at NeuroAthlete, when we dive into how the nervous system really works, we can understand why stretching doesn’t increase flexibility, and how to actually make real, lasting improvement to this property of fitness. Here are three ideas that can help your understanding of this:
- First, you have to understand that muscles have no ability to be “tight” or “loose” on their own – the brain controls how much reflexive (unconscious) tone muscles carry by innervating them to various levels of tension. How do we know this? Well, under anesthesia, you could do the full splits, or we could easily fold you in half to touch your toes!
- Secondly, it is very difficult to actually stretch most of the tissues in the body intensely or long enough in a typical training environment to create plastic deformation (i.e. the muscles tissues actually lengthen). So, when you are watching Olympic gymnasts or professional dancers and admiring their “flexibility”, just realize that it took hours a day over many years to achieve that extreme level of flexibility. And, it is a very “sport specific” flexibility.
- Lastly, most studies indicate that the majority of improvement from stretching is primarily due to an increase in stretch tolerance, as opposed to any significant change in tissue length. This is because taking a muscle into a very lengthened (stretched) position is generally threatening to our brains at an unconscious level – our brain doesn’t want to tear something because that is bad for survival!
The reason stretching does not really improve flexibility comes down to our brain’s map of us for movement, called a proprioceptive (or sometimes somatosensory) map. When this map is very detailed and clear we have fluid, coordinated, supple movement. But if the map is less detailed and clear, the unconscious brain interprets this as threatening, just as you feel more threatened when driving through a fog bank versus driving on a clear day. The detail and clarity of this map predominantly comes from special nerve endings in the joints, muscles, and tendons that feed the brain input about these structures, especially the joints. So, when joints get jammed up, the signals are not sent as strongly and the brain’s map gets “cloudy”. In most people, this results in general stiffness, like tight hamstrings or a stiff neck or back, etc. Think of this as a threat response from the brain. Our brains are “putting the brakes on”, basically because it can’t “see” you as well, and tightening up muscles keeps you safer in this “foggy” map condition.
The deception that happens is that stretching often feels good, and after a bout of stretching we’ll often see a small improvement in range of the area or muscle stretched. So, it must be making an improvement, right? Well, the research says no, not really. The average amount of time you actually get to keep that increased flexibility is… six minutes. But none of us actually check our flexibility 15 minutes after a stretching session, right?! We check it immediately, we see we’ve gained flexibility, and we think the stretching is making a long-term change….
So, how do we make positive, long-term change for our clients in terms of flexibility? For the average person or gym goer, improving joint mobility makes huge changes in what most people perceive as flexibility. This is because joint mobility drills un-jam our joints, thus better signals are sent to the brain, and the brain’s movement map gets more detailed and clearer. When this happens the unconscious brain “takes the brakes off” and relaxes muscles more with a clear movement map. We regularly see drastic “flexibility” improvements immediately after doing joint mobility with our clients. And when they continue the drills we’ve taught them at home (spoiler alert: it takes WAY less time than traditional stretching!), we see real, positive change in mobility and range of motion. For our competitive athletes, we often have to focus on position, speed, and activity-specific flexibility protocols that include strengthening end-range of motion and external targeting.
We hope this was informative and let us know if you have any questions. In future blogs we’ll discuss more about the concept of flexibility and the real ways you can improve it.