Yoga’s holistic approach combines ancient Indian philosophy with physical activity and a healthy lifestyle in general. Most yogis don’t practice to achieve a certain fitness goal but rather to reach a peace of mind, live sustainably in tune with mother nature and to achieve a healthy diet, soul and body. Since yoga reached the western culture it brought us it’s richness of ancient knowledge such as the yoga sutra, the Bhagavad Gita or the chakra teachings. At the same time nowadays yoga practice wouldn’t be as rich as it is today if it hasn’t received many great influences from western knowledge such as anatomy, research about our digestive system and nutrition, our neurological system and also about how to design a training program based on the adaptive systems of our body.
Especially for yoga teachers nowadays, it is mandatory to learn about both parts. To be a well-prepared yoga teacher, you need to learn the yoga sutra as well as the anatomy of bones and muscles. In your teacher training you learned about the ways that chakras can be blocked as well as about how to safely teach a yoga session to avoid any injury in the delicate system of our articulations.
The combination and integration of ancient wisdom and modern scientific knowledge is the perfect match and can offer us the best yoga experience to achieve a healthy mind, soul and body.
While there has been tons of research about cardiovascular-endurance training and strength-resistance training and how to effectively and safely design training programs, there hasn’t been so much research about flexibility training up until the recent past. For a very long time, this part of physical conditioning has completely been ignored.
For the last 20 years there has been great scientific research about how to effectively improve our flexibility and range of motion and how to design mobility programs safely and with a scientific approach. Let’s review the methods of how to achieve more flexibility, and let’s then see how we can use this to be better yoga teachers and help our students and ourselves to reach our goals.
The Scientific Way to More Flexibility
When talking about the best way to achieve more flexibility, most people and even most yoga teachers think foremost and often only about the adequate exercises. While this is of course an important topic, it is just ONE component of many when it comes to a successful stretching regimen. We have an almost infinite number of amazing asana to choose from, but all the other important components are widely ignored. They consist of:
- Time per stretch
- Sets per exercise
- Sessions per week
- Resting time
Although equipment is not mandatory for yoga and flexibility training, it helps a lot to improve the execution of the exercises. As yoga itself is a holistic approach, consider using high quality and sustainable equipment.
There are four general methods for stretching:
- Dynamic Stretching: This method uses dynamical movements through the complete range of motion (ROM) with controlled drills. You can find this approach mostly in vinyasa yoga or ashtanga yoga.
- Balistic Stretching: consists of a less controlled muscular effort than the dynamic stretching method. It uses bouncing-type movements in which the end position is not hold. You will rarely find this method in yoga, apart from some repeated jumps or maybe kundalini yoga swings.
- Static Stretching: stretching and holding the respective position/asana for a specific amount of time. You can find this approach mostly in yin yoga or some hatha yoga classes.
- PNF Techniques (proprioceptive neuromuscular facilitation): this approach almost invariably works with a partner and combines 3 different phases:
- Passive pre-stretch
- Muscle activation with the help of a partner
- Passive stretch
Static stretching and PNF are superior to increase range of motion (ROM). A recent review from 2018 shows when comparing the four mentioned stretching methods, ballistic stretching has by far the smallest effect on range of motion, and it is also the method that is most prone to injuries.
You can still improve your flexibility with dynamic stretching and ballistic stretching, as most studies showed that doing any kind of regular mobility training can increase the range of motion when compared to no targeted training. But static stretching and PNF show the most efficiency. Comparing those two methods, which one is the best?
While there has been some research from 2006 (Sharman et al) concluding that PNF ist the most effective method especially for short term gains in ROM, there has also been other studies for example from 2018 (Lepke et al) showing that PNF and static stretching show very similar results for increasing flexibility.
The meta research most interesting is also from 2018 and was conducted by Dr. Thomas et al. It compares 23 different studies with all the above-mentioned stretching typologies and concludes that a static stretching protocol shows significant gains in ROM compared to PNF and even more compared to the other two methods.
Transfer this knowledge now to our real life situation: while PNF might be a very interesting and effective tool to use as yoga teacher in a 1:1 session, partner sessions or also while correcting individual students in a group session, for most students and for ourselves the static stretching might be more realistic as it can be done individually alone or in big groups and also for every muscle group whereas PNF almost always requires a partner and can be difficult for some muscle groups such as the glutes etc.
Now that we know all our asanas from our yoga teacher training, and from research we know that the most effective stretching method is the static stretching or the PNF we can move on to the next components.
Time of Stretching per Set & Stretching Time per Week
These two components should determine how long we should hold a specific asana, how often we should repeat the asana per practice (or do a similar asana with the same target muscle group) and how often and long we should practice per week when it comes down to the mere physical aspect of gaining flexibility – and dear reader hold on here, we will come back to a more holistic approach to yoga by the end of the blog!
30 seconds seems to be the most efficient duration (Brandy et al (1994 & 1997)) as it leads to an increase in ROM compared to 15 seconds, whereas 60 seconds did not realize any further benefit.
Another aspect of training, however, might be even more important: the complete time spent stretching per week (Thomas et al (2018)). This means that the exact stretching duration per session is not as significant as how much time is spent in total during the week.
The best method is to stretch 5-10 minutes per week, per targeted muscle group in comparison to less than 5 minutes which leads to a less developed ROM or compared to more than 10 minutes which neither brings any better results.
So the optimal strategy is:
- 3 sets of 30 seconds per muscle group, 6 days per week = 9 minutes per week per muscle group
If you cannot dedicate time every day, you can try to allocate the weekly time in fewer sessions, because the total duration is the most important factor here. Here is another example:
- 3 sets of 60 seconds per muscle group, 3 days per week = 9 minutes per week per muscle group
In part 2 of this blog I will translate all of these findings into our yoga asana practice, but what I would like to underline already at this point is that this study shows something most of us yoga teachers keep telling our students and which most of them still don’t believe: you can design your yoga practice in the way it fits your personal life! It doesn’t matter if you do a 60-minute session once per week or if you do a „small“ 10-minute session per day as long as you regularly step onto your yoga mat you have already won!
Rest & Intensity
The exact rest time between sets hasn’t been studied yet, but the rest time used in most studies was 1-2 minutes between two sets. Another finding that I think is very interesting for us yoga teachers is that a study from Wyon in 2009 with 24 adolescent dancers in a 6-week stretching program showed that low intensity static stretching produced greater results in flexibility compared to a moderate-intensity static stretching approach. This means that a gentle and controlled stretch intensity will bring more benefit and less danger of injury, instead of forcing ourselves (and our students) too hard to achieve a perceived perfect asana. If our students want to increase their flexibility, they should reach a gentle stretch sensation, but they shouldn’t feel pain.
Again: I will come back on how to use this knowledge as yoga teacher to design a well-rounded yoga sequence but the most interesting finding for me here was about the low intensity stretch approach and also thinking more about the rest, which could mean to build our yoga sequence in a way that the same muscle group will be targeted at least 3 times per session and also to always use asanas in between that will target different muscle groups to give a break between these 3 times or to use the Childs pose always before doing another asana that will target the same muscle group.
Warm-Up, Breathing & Periodization
It is a commonly known but widely ignored fact that the body should be warmed up before going into more intense stretches. This knowledge is already used by many great yoga teachers through time. It suggests that an ideal yoga sequence would start with gentle asana that don’t go too deep into stretches but rather warm up the whole body system and get the blood circulation going, such as sun salutations in the beginning of the yoga practice before going into deeper yin yoga style stretches. Other styles such as Hot Yoga use a increased room temperature for the same purpose.
A very useful approach can also be the „Anderson Method“ which uses for every asana an easy pre-stretch for 10-30 seconds and then easing into a developed full stretch for another 30-60 stretch in order to calm down our neural reflexed.
While our ancient yoga traditions teach us a lot about pranayama and about breathing in our asana practice, the breath is yet to be scientifically researched in the context of stretching. The little research that is made supports many ideas of how we use breath in yoga: the studies suggest to breath out during a stretch and to generally breath calm and slowly during the stretching session to help our muscles to relax and decrease the activity of neural reflexes that could oppose the stretch.
Training periodization is widely used in endurance and strength training but not so much in yoga or other stretching protocols. Periodization describes the planning of the training over several sessions and weeks with a easing in phase, a peaking phase and a rest period. Studies suggest that every 6-8 weeks of regular stretching training, there should be a rest period of 3-5 day with either complete rest or a „deload week“ with very easy going low intensity training sessions. Some ashtanga yoga studios use a similar approach, offering yin yoga session in between ashtanga sessions to balance the yin and the yang in our bodies and minds.
Now check out part 2 of this blog (“Stretching: How to Apply Scientific Research to Your Yoga Practice?) to find out how to translate all of these findings into your yoga practice.
About the author:
Julia Johann (@julinhajohann) is a fully-fledged Yogi, Professional Dance Teacher and Fitness Trainer from Germany. She harnesses yoga and science to improve flexibility and awareness in her everyday life.