Why does Yoga help to reduce stress and anxiety?
How to improve your quality of life?
Stress and anxiety have been implicated as contributors to many chronic diseases especially in western societies. In our busy lives we often feel overwhelmed and not able to handle our day to day life which can lead to feeling defeated or lost at times. Being stressed out or even suffering from anxiety leads to a decreased quality of life, and might often require pharmacologic treatment, if not dealt with on time.
To avoid the excessive use of (prescription) drugs and to use a more natural way to calm the mind and to release stress, yoga is a good alternative. Especially the physical part of yoga, hatha yoga through asanas and pranayama is known to reduce stress.
Review of existing empirical studies
This article will give an overview on the current status quo of existing empirical studies to analyze the benefits of yoga on managing stress and reducing anxiety. The studies consulted are based on different test groups. Each study also uses a set of procedures to measure the influence of yoga on stress and/or anxiety. Parameters and hypotheses that serve as starting points in each study vary. Results of test groups were measured through physiological variables, such as perceived stress level, mindfulness and self-compassion, as well as with biological variables relating to blood components and heart rate variations used by the human body in reaction to danger (or stress) and the reduction of these levels before, and after practising yoga. This will allow for a wider overview on the topic and also point out limitations of the current level of results.
Outline of this article
The definition of anxiety and stress and how both of these emotional states can be measured will be explained in the first chapter.
The results of different studies will be presented and summarized in the following chapter. The chapter will compare results of several studies with different test groups – that all have in common to show the benefits from doing yoga to not doing yoga at all. In addition the aspect of doing yoga on a regular basis will be pointed out as well, as there is a difference between doing one class of yoga vs. practising yoga frequently.
It will also be described how yoga affects our body and mind in a positive way and what creates the shift that yogis feel from before and after a class of yoga. There are certain asanas that are specifically beneficial to reduce anxiety.
Stress and anxiety
Everybody experiences stress in day to day life. It presents itself in different ways, such as a too quickly snapped answer to an innocent comment, a pounding headache at the end of the day, the inability to take a decision in a situation of overwhelm or the impatient ticking of the finger from our colleague during a team meeting.
Importance of stress and anxiety today
Stress has been a part of humans’ life ever since, but particularly in western societies it has increased significantly in the last century. Stress typically produces a negative psychological impact when an individual is challenged or threatened. The individual can regain balance by using appropriate stress management techniques.
Americans are among the most stressed-out populations in the world. Drawing from Gallup’s 2019 data on emotional states, over half of the American population experience stress during the day. This is 20% higher than the world average of 35%.
How common is stress?
- About 33 percent of people report feeling extreme stress.
- 77 percent of people experience stress that affects their physical health.
- 73 percent of people have stress that impacts their mental health.
- 48 percent of people have trouble sleeping because of stress.
Stress is considered a crucial trigger for physical and mental illness. Most stress is a normal part of daily life, and can be coped with adequately by the individual. Prolonged or more serious stress however may require professional help. 80% of modern diseases have their beginnings in stress.
The autonomic nervous system
The autonomic nervous system controls and regulates the internal organs without any conscious recognition or effort by the organism. There are two sets of nerve systems: the sympathetic and parasympathetic nervous systems.
The sympathetic nervous system connects the internal organs to the brain by spinal nerves. It prepares the body for the flight or fly modus in situations of stress (or survival) When stimulated, these nerves prepare the organism for stress by increasing the heart rate, increasing blood flow to the muscles, and decreasing blood flow to the skin.
The nerve fibres of the parasympathetic nervous system are the cranial nerves, primarily the vagus nerve, and the lumbar spinal nerves. It’s main function is to restore and regenerate after phases of stress. When stimulated, these nerves increase digestive secretions and reduce the heartbeat.
When there is an overly stressed situation on the autonomic nervous system the body can no longer function correctly. Both systems need to be in balance.
What are the effects of stress in our body?
Stress stimulates the hypothalamus of the central nervous system to activate endocrine and sympathetic nervous systems, which trigger a series of physiological reactions. Increased and stronger heart rates increase cardiac output, increased blood pressure supplies the body with blood more efficiently, increased blood sugar released by the liver nourishes muscles, and a suppressed immune system increases the possibility of infection.
How to measure stress and anxiety
Ways to measure stress in participants of studies is the Perceived Stress Scale (PSS). It is a 14-item self-report measure designed to assess “the degree to which situations in one’s life are appraised as stressful”. Specifically, items are designed to measure the extent to which one’s life is perceived as “unpredictable, uncontrollable, and overloading”. In current studies it has been used in order to measure stress levels before and after yoga classes and/or with and without taking yoga classes in general.
Benefits of yoga for reducing stress
Study 1: Stress in middle aged women
Huang, Fu-Jung; Chien, Ding-Kuo; Chung, Ue-Lin studied the effects of Hatha yoga on Stress in middle- aged women(40-60 years old). Test group of this study consisted of middle aged women (40-60 years old), divided into 3 test groups: group 1 did not practise yoga, group 2 practised 1 hour of hatha yoga and group 3 practised hatha yoga once a week for 12 weeks. The test result showed that group 2 showed slightly less stress than group 1 without yoga. But the more significant change in stress level appeared in the test group 3 that practised yoga once a week for 12 weeks.
They used a quasi experimental design and recruited 63 female community residents in New Taipei City aged 40–60 years. Participants were randomly divided into an experimental group (n = 30) and a control group (n = 33). The experimental group received the 8-week Hatha yoga course. The control group received no intervention.
The Perceived Stress Scale (PSS) and heart rate variability (HRV) assessed stress reduction effectiveness. Chi-square, independent t test, paired t test, and generalized estimating equations were used for data analysis.
Results showed the post intervention HRV and PSS of the experimental group decreased significantly (p < .001) more than the control group.
Participation in a single 90-minute Hatha yoga class can significantly reduce perceived stress. Doing Hatha yoga regularly can reduce perceived stress even more significantly.
Therefore the best stress reduction was found to be met when practising yoga frequently.
Study 2: The Effects of Yoga on Anxiety and Stress
Focus was to assess human trials and how the practise of hatha yoga could improve the signs and symptoms of stress and anxiety. Of 35 participants 25, that is 71% showed a significant decrease in stress and/or anxiety symptoms when yoga was practised on a regular basis.
Yet limitations of this study’s result was the small number of participants now allowing for reliable and consistent test results on a larger scale. 40% of participants reported biochemical and physiological markers of stress and anxiety, but yielded inconsistent support of yoga for relief of stress and anxiety.
Inversions are enormously beneficial for the nervous system because the head is below the heart. This has a soothing effect on the nervous system and will tone down stress. Inversion also encourages fresh oxygenated blood to flow to the brain in order to manage anxiety, depression and insomnia.
Stress can be reduced when yoga is practised on a regular basis, but it will require additional research for consistent test results in a larger test group.
Study 3: Role of Yoga in stress management
Modern medicine focuses on preventive measures. Primary prevention focuses on reducing health risks, preventing disease, and encouraging regular exercise. Regular exercise is not always convenient due to busy lifestyles. This study approaches the benefits generated by yoga through the strong relationship between body and mind.
A relaxed mind will lead to a relaxed body and its muscles. The authors state that through physical postures and breathing (pranayama) muscle strength, flexibility, blood circulation, oxygen update and hormone functions of the body improve.
Meditation stabilizes the autonomic nervous system with a tendency towards parasympathetic dominance. Physiological benefits which follow, help yoga practitioners become more resilient to stressful conditions and reduce a variety of important risk factors for various diseases, especially cardio-respiratory diseases.
The results of our study suggest that a single 90-minute class of Hatha yoga significantly reduced perceived stress and physical stress. It was also shown that long-term yoga participation is better than a single yoga class in achieving effective stress reduction.
In order to improve the overall health situation of communities, firms, and government agencies the authors state that employers should offer yoga-related courses as a way to reduce general stress and improve general health among their employees and the general public.
Benefits of yoga for stress and anxiety management are found through an increased positive mindset and a balanced autonomic nervous system when practising yoga (asanas, pranayama and meditation) regularly.
Study 4: Physical and perceptual benefits of yoga asana practice
Test group were 26 healthy adults aged 20–58 years old. They participated in an Ashtanga or Hatha Yoga class for the duration of 6 weeks. The study analyzed the different impacts between the two Yoga styles in terms of physical fitness muscles and stress (measured by diastolic blood pressure).
All participants were able to reduce perceived stress level and to improve core strength, endurance, flexibility and health perception.
Yet the participants from the Ashtanga group outperformed the Hatha group.
While the Ashtanga group had decreased diastolic blood pressure and perceived stress, and increased upper body and trunk dynamic muscular strength and endurance, flexibility, and health perception, the Hatha group “only” improved their core strength, endurance, and flexibility.
The extent on how Yoga practices will reduce stress depends on the Yoga style: Ashtanga should be the preferred choice for stressed out yogis in comparison to hatha yoga.
Study 5: The Health Benefits of Yoga and Exercise
This research paper is based upon a literature review that compares the benefits of exercise versus yoga to improve and maintain physical and emotional health.
It is especially focusing on yoga’s positive effect on our bodys by down-regulation of the hypothalamic–pituitary–adrenal (HPA) axis and the sympathetic nervous system (SNS).
The test groups considered healthy and diseased participants and in both cases yoga was more effective than exercise.
Yoga interventions appeared to be equal or superior to exercise in nearly every outcome measured except those involving physical fitness.
In summary it can be stated that a regular practise of asanas and pranayama, often named as Yoga practise in publications, has a positive effect on managing stress and reducing anxiety. Nevertheless current clinical studies with a sufficient number of participants are rare to non-existent. This will lead into the critical recognition of the current status quo.
Summary and outlook
Although there seem to be a growing number of research papers carried out on reducing stress with yoga, only seven mechanisms have been empirically examined. The existing studies are mainly based on three psychological mechanisms (positive affect, mindfulness and self-compassion) and four biological mechanisms (posterior hypothalamus, interleukin-6, C-reactive protein and salivary cortisol).
While the psychological mechanisms can be investigated through questionnaires, the biological mechanisms need to be measured through medical equipment (blood samples, heart rate variation measurement) to determine the level of stress and its evolution before and after practising yoga.
Although the positive effects seem to be obvious for anybody practising yoga, the empirical proof is yet to be improved through bigger test groups and more reliable testing methods. Many external (disturbing) stressors might also affect test results in an implicit way.
Future clinical trials are needed to examine the distinctions between exercise and yoga, particularly how the two modalities may differ in their effects on the SNS/HPA axis. Additional studies using rigorous methodologies are needed to examine the health benefits of the various types of yoga.
Any of the studies were carried out on small study populations, lack of randomization, and lack of a control group.
In statistical models, small study populations lead to an overproportional error factor delta, because one “wrong” test result will be overly represented when creating a larger scale model based on these small test fields. More studies need to be carried with a bigger test population to gather more reliable data and results.
- Li, Amber W.; Goldsmith, Carroll-Ann W.< The Effects of Yoga on Anxiety and Stress. In: Alternative Medicine Review . Mar2012, Vol. 17 Issue 1, p21-35. 15p. 7 Charts.
- Huang, Fu-Jung; Chien, Ding-Kuo; Chung, Ue-Lin, Effects of Hatha Yoga on Stress in Middle Aged Women, in: Journal of Nursing Research: March 2013 – Volume 21 – Issue 1 – p 59-66, https://journals.lww.com/jnr-twna/fulltext/2013/03000/Effects_of_Hatha_Yoga_on_Stress_in_Middle_Aged.9.aspx
- Role of yoga in stress management. The West Indian Medical Journal, 01 Jun 2004, 53(3):191-194 PMID: 15352751 https://europepmc.org/article/med/15352751
- The Health Benefits of Yoga and Exercise: A Review of Comparison Studies, The Journal of Alternative and Complementary MedicineVol. 16, No. 1The Health Benefits of Yoga and Exercise: A Review of Comparison Studies, Alyson Ross and Sue Thomas Published Online:27 Jan 2010 https://www.liebertpub.com/doi/abs/10.1089/acm.2009.0044
- Physical and perceptual benefits of yoga asana practice: results of a pilot study, Author links open overlay panel, Virginia S.CowenTroy B.Adams, Journal of Bodywork and Movement Therapies, Volume 9, Issue 3, July 2005, Pages 211-219, https://www.sciencedirect.com/science/article/abs/pii/S1360859204000610