Written with Sarah Campbell. Be sure to read Part One and Part Two first.
How long to stretch in yoga?
At the beginning and end of vinyasa flow yoga classes we often hold yoga stretches (say a reclined twist, or garudasana arms, or pigeon pose) for a few breaths up to interminably long durations that have us dreaming of our post class smoothie. But, is there a logic to how long we hold poses? Do you know how long to hold a yoga pose? Specifically, how long to hold the yoga static stretches, both passive and active, generally offered in a group yoga class environment?
A review of literature suggests to hold stretches about 15-30 seconds with 2-4 repetitions. These durations and repetitions have been shown to improve flexibility. Older adults may need longer stretch times, with 60-second holds proving effective for this population. Studies suggest that beyond these durations and repetitions there is no increase in muscular length[i]. At this length of stay you are not permanently changing the muscular structure but rather working with the nervous system and stretch reflex and allowing the muscle to relax[ii] or releasing the active tension[iii].
This is the simple answer, but of course the body is not simple and individuals are not standardised. Duration and frequency of stretch needed to increase range of movement vary by individual, technique, and by muscle group. When working with yourself or an individual student out of a group class it may be beneficial to be more inquisitive and nuanced in your approach. In your practice you can stretch until you feel a small amount of tension but not pain. When this tension diminishes you can go a little further until you feel the original amount of tension. When that tension diminishes you can release the stretch[iv]. This approach demands a fair amount of caution and self-care so the body is not pushed to extremes.
Does stretching increase range of movement?
Stretching works to increase the range of motion of muscles and connective tissues in relationship to the reflexes that govern their contraction and lengthening. Stretching a target muscle in short intervals, three days per week, for a total of nine minutes per week has been shown to improve flexibility[v]. This bodes well for consistent and varied yoga practice with high degree of frequency and repetition of individual stretches. In general, flexibility within this context is developed by developing a greater stretch tolerance[vi]. In other words, in the typical short interval static stretches we do in yoga to improve flexibility we are mostly working with the nervous system and its reflexes to build up a greater tolerance to the sensation of stretch and ability to relax.
To illustrate: the most common example of explaining how our flexibility is mostly a function of the nervous system is that of a medical patient under anesthesia. When anesthesised, the nervous system’s maintenance of muscles is effectively shut down and an individual’s muscles become so loose and ‘flexible’ that great care has to be taken not to move a patient in a way that will tear or damage their muscles and connective tissues. What keeps this same individual ‘inflexible’ in real life is mostly the protective reflexes and habits of the nervous system rather than connective tissue restraints. ‘Flexibility’ and ‘inflexibility’ are governed largely by the activity of the nervous system[vii].
There are of course yogis who have been at it for years, working with their stretch tolerance through consistent practice, and have not seen ‘enough’ change to their range of motion. Assuming that the need for increased flexibility is rational and reasonable, this need to be flexible-yogi may need to do more than work with stretch tolerance through the typical short duration holds offered in a typical yoga sequence. Mindful and safe longer holds may help develop permanent elongation through the connective tissues and muscular fibers. Tactics to achieve this vary and sometimes bring up strong opinions.
What if we stretch for a long time?
Light on Yoga advises a variety of times for postural holds with holds of 30-60 seconds instructed for poses like Janu Sirsasana and Upavishta Konasana and up to 5 minutes in Paschimottanasana[viii]. In general, Mr. Iyengar’s advice is sound at least on the shorter end of the spectrum. Longer holds, although they may, as we will see, introduce lasting and needed change to muscular fibers, can also introduce their own liabilities if not practiced carefully.
Moving beyond a 30-second hold comes the possibility that you are no longer just working with muscles and can begin to lengthen the connective tissue (fascia); a process that may build the length of the muscular fibers permanently[ix]. The amount of time to hold a pose to achieve the aim of working with connective tissues toward permanent elongation can vary widely and is subject to caution. Some teachers advise a 90-120 second hold on it to change the structure of fascia[x] while others can go upwards to 30 minutes if that is required for individual needs. It is clear that in order to work with flexibility you must work with fascia, which requires a bit more time than muscle fibers to unwind. In addition to time, fascia may also need the movement and hydration generated by dynamic stretch (See Part Two)[xi].
2019 Update: Fascia is not separate from muscles. There is new information about the composition and role of fascia coming out consistently. We should be more critical in our acceptance of ‘facts’ than I was when I wrote this in 2016. At this moment I do not intend to rewrite this with a more nuanced understanding of the role of fascia, so I refer you to Jules Mitchell’s Yoga Biomechanics: Stretching Redefined (2019). Mitchell notes “the idea that fascia can become more fit, more pliable, or less restrictive in response to certain methods of movement or massage is most usually met with either blind acceptance or staunch skepticism.” This reminds us to keep our critical thinking hats on and continue to experiment and survey new research studies as they emerge.
On the issue of time and stretching, Mitchell adds: “When human connective tissues creep, they become temporarily lengthened. Creep is not a plastic response, nor an elastic response, but a viscoelastic response. Upon unloading, the tissue recovers and returns to its resting length, although at a slower rate than an elastic material. Even in the case of prolonged, progressive creep, the tissue recovers. Additionally, creep is not damaging to the collagen fibers as perhaps an abrupt, forceful stretch might be… I am not aware of any studies measuring the short-or long-term positive adaptive response to stretching interventions of passive 3-5 minute holds resembling those of a yoga class, where creep is the mechanism of action central to the study design…” Mitchell summarises that “we cannot confidently conclude tissue changes in length as a response to stretching.”
Working with long holds has potential liabilities so we do not recommend extended holds without support at the joints, or mindful awareness of sensations at the joints. In long held yoga postures, past one minute, you risk beginning to stretch the non-elastic ligaments that maintain the integrity of joints. Once they are stretched they do not return to their original length and can lead to dislocation and injury[xii][xiii]. Outside a therapeutic or medical environment, in which it has been determined there is a need, such as the abundance of scar tissue to restore mobility at a joint, it is inadvisable to stretch ligaments. To avoid stretching ligaments in long holds students should be advised to stop stretches when pain or discomfort or the feeling of stretch comes directly into a joint area[xiv]. Additionally, as is the practice in restorative yoga, supportive props can be used to prevent pressure coming into joints[xv].
What about Yin Yoga?
Yin yoga, which specialises in long holds, is in general practiced very gently and with absolutely no pain. It is also not necessarily about stretching, rather yin yoga aims to stress connective tissue, which is often very different to simply stretching it. The basic tenet of yin yoga is to find just the very start of resistance or sensation within the pose and then remain still – it is not an extreme stretching regime.
Yin teachers may dispute this advice, and if you’d like you can see a different view check out the following:
Know your intentions
It is important to be clear on your intentions and the effect that long holds have on the body. It is important not to confuse yourself and students with the intention of a long hold. Is it to stretch tissues, or to calm the mind? If it is to stretch muscles and connective tissues (and depending on your view on it, to stress ligaments) than it is advised not to go to extremes and potentially use support. If your intention is to simply calm the mind, then it is probably better to avoid deep stretch altogether and either choose a simpler posture or use extensive support. Or just lie down and have a good savasana.
Stay tuned for Part Four where we will detail how to sequence stretching throughout your yoga class or practice.
Photos by Mimi Kuo-Deemer
Practise these concepts with my 90-minute online workshop, ‘Beyond Stretching’ available on-demand.
Works Cited:
[i] Page, P. (2012). Current Concepts in Muscle Stretching for Exercise and Rehabilitation. International Journal of Sports Physical Therapy , 7 (1), 109-119.
[ii] Coulter, D. (2015, June 14). Stretching: What Does it Really Mean? Retrieved October 26, 2016, from Yoga International: https://yogainternational.com/article/view/stretching-what-does-it-really-mean
[iii] Page (2012)
[iv] Ian Shrier, M. P., & Kav Gossal, M. (2000). Myths and Truths of Stretching: Individualized Recommendations for Healthy Muscles. The Physician and Sportsmedicine , 28 (8).
[v] Mitchell, J. (2014, November 18). Stretching Does Improve Flexibility. Retrieved October 26, 2016, from Jules Mitchell Yoga: http://www.julesmitchell.com/stretching-does-improve-flexibility/
[vi] Page (2012)
[vii] Coulter (2015)
[viii] Iyengar, B. (1979). Light on Yoga. New York: Schocken Books.
[ix] Coulter, H. D. (2001). Anatomy of Hatha Yoga. Honesdale: Body and Breath.
[x] Gudmedstad, J. (2007, August 28). The Anatomy of Safe, Effective Stretching. Retrieved October 26, 2016, from Yoga Journal: http://www.yogajournal.com/article/teach/what-s-in-a-stretch/
[xi] Myers, T. (2016, September 13). Q&A with Tom: Optimal Time to Hold Yoga Pose? Retrieved October 26, 2016, from Anatomy Trains: https://www.anatomytrains.com/news/2016/09/13/qa-tom-optimal-time-hold-yoga-pose/
[xii] Mitchell, J. (2014, August 12). Viscoelasticity. Retrieved October 26, 2016, from Jules Mitchell Yoga: http://www.julesmitchell.com/viscoelasticity/
[xiii] Coulter (2001)
[xiv] Gudmedstad (2007)
[xv] Mitchell, J. (2014, August 27). Creep and Recovery. Retrieved October 26, 2016, from Jules Mitchell Yoga: http://www.julesmitchell.com/creep-and-recovery/
