What is flexibility and what is mobility? Often they are terms used very loosely but they in fact have different meanings. Flexibility is defined as "the ability of a muscle or muscle groups to lengthen passively through a range of motion", whereas mobility is the "ability of a joint to move actively through a range of motion". Many additional structures define how good a person's mobility is. It is not only the muscles stretching over a joint but also how far the joint moves within the joint capsule. Mobility also takes into account the component of motor control within the nervous system. (http://ssphysio.com.au/view/post/mobility-vs-flexibility)



There are several different types of stretching, static, dynamic, ballistic and proprioceptive neuromuscular facilitation (PNF). In this post, I wanted to focus on PNF stretching as it is a more advanced form of flexibility training and is one of the most effective ways to improve flexibility and increase range of motion. If you’re wondering what on earth PNF stretching is or how you do it, the steps of how to perform a PNF stretch below may help you.

 1.     The muscle group to be stretched is positioned so that the muscles are stretched and under tension.

2.     The individual then contracts the stretched muscle group for 5 – 6 seconds while a partner, or immovable object, applies sufficient resistance to inhibit movement. 

3.     The contracted muscle group is then relaxed and a controlled stretch is applied for about 20 to 30 seconds. The muscle group is then allowed 30 seconds to recover and the process is repeated 2 – 4 times 

PNF stretching may sound inconvenient because it typically involves a partner—but there is a way to perform self-administered PNF stretches. For example, to perform a self-PNF hamstring stretch, place your foot on a chair or bench and perform a static stretch followed by an isometric contraction and another static stretch. Research has shown that this is an equally effective way to reap the benefits of PNF stretching.

(Sharman MJ, Cresswell AG, Riek S., 2006)[TF3] 


How Long Does it Take to improve flexibility?

This is not a question that has one answer for all – the answer to this question would depend on numerous things such as how often and long you stretch for and also your genetics will play a part in how quickly and how much your muscles will change. For example, in gymnastics training for one of my elements I knew I had to get super flexible hamstrings, so I stretched my hamstrings every training session for a good amount of time and my flexibility improved quickly. Whereas I would just quickly stretch my shoulder and back most sessions if I remembered too and I didn’t see much difference in my flexibility in those areas. So, if you’re serious about improving your flexibility and set time aside to regularly stretch, then you should definitely start to notice changes in the first month (be patient, flexibility isn’t something that you get overnight). One thing you’ll really see is that if you focus on improving flexibility, your technique in your CrossFit movements will reap the benefits.

Happy stretching guys!


Sharman MJ, Cresswell AG, Riek S. (2006) Proprioceptive neuromuscular facilitation stretching: Mechanisms and clinical implications. Sports Medicine. 36(11): 929-39

Walker (2019) Proprioceptive Neuromuscular Facilitation – How to do it, precautions to take, safety guidelines, and PNF stretching examples.https://stretchcoach.com/articles/pnf-stretching 

Martyn Jennings

Amature Photographer, Father, Part Time Crossfit,