Exploring the Multidimensional Health Effects of Yogasana: A Comprehensive Overview

Abstract

The term “Yoga” is derived from the Sanskrit root “Yuj,” which translates to “to join,” “to yoke,” or “to unite.” Its global appeal stems from its evidence-based holistic approach. Today, a robust scientific consensus exists on the therapeutic benefits of Yoga, supported by a burgeoning body of research. Various Yogic practices, including asana (physical postures), pranayama (breath control), and dhyana (meditation), offer multifaceted health advantages. Yogasana, a cornerstone of Yoga, integrates physical postures with controlled breathing techniques to enhance physiological, psychological, and emotional well-being. As the third limb of Ashtanga Yoga, Yogasana yields diverse physiological effects, from cellular modulation to systemic improvements across the human body. Sukshma vyama, a subset of Yogasana, promotes localized blood circulation and facilitates articulation in synovial joints, thereby optimizing biomechanical alignment and mitigating muscular imbalances. Moreover, Yogasana induces slower, deeper breathing patterns, eliciting a predominant activation of the parasympathetic nervous system, which is crucial for stress management in modern society. Specific asanas stimulate digestive functions, facilitating the absorption and elimination of metabolic waste products, thereby fostering gastrointestinal health and optimizing the gut-brain axis. This chapter offers a comprehensive synthesis of scientific literature elucidating the physiological and psychological effects of Yogasana practice, providing an empirically grounded understanding of its therapeutic potential.

1. Introduction

Yogasanas find first placein “Hath Yoga pradipika” and third place in “Patanjali Ashtang Yoga.” Asanas constitute a vital aspect of Yoga, although there is a common misconception that Yoga solely revolves around physical postures. However, it is imperative to distinguish asanas from mere postures or exercises, as the former entails a conscious integration of breath awareness. While assuming a specific posture, one’s mind may wander, but the practice of asanas necessitates focused attention.

Presently, a substantial portion of scientific inquiry is directed toward unraveling the effects of Yogasanas. In this discourse, an attempt has been made to examine the physiological and psychological impacts of various Yogasanas comprehensively.

In Patanjali’s Yoga-darsan an asana is defined as – sthiram sukham asanam. ‘स्थिरसुखमसनम् I. ‘According to Patanjali, “steady and comfortable posture is asana” [1]. Any posture that can be maintained with comfort is an asana.

2. Classification of asanas

As per traditional texts, the asanas can be classified mainly into 03 categories [2, 3, 4]:

1. Cultural Asanas

2. Relaxative Asanas

3. Meditative Asanas

2.1 Cultural asana

This category represents diverse asanas that offer a comprehensive approach to the physiological and psychological well-being of an individual. These asanas serve as foundational practices, priming individuals for more advanced Yogic techniques. They entail dynamic movements involving various joints around multiple anatomical axes and planes, including flexion–extension, abduction–adduction, and external–internal rotation. Performed in various positions such as standing, kneeling, sitting, prone lying, and supine lying, each asana imposes unique physical and biomechanical demands, contributing to the complexity of the practice. From a physiological standpoint, these asanas are instrumental in fortifying the musculoskeletal system through static stretching, which enhances muscle tone and flexibility. Notably, they optimize spinal column mobility, facilitating maximal vertebral movement. Moreover, these practices elicit profound effects on visceral organs within the thoracic and abdominal cavities by modulating intra-abdominal pressure. This regulation supports the proper functioning of vital organs, thereby promoting overall health and vitality [2, 3, 4].

2.2 Relaxative asanas

Asanas that place the body in a lying position—either supine or prone—are considered relaxing asanas. When lying down, the body is entirely supported on a surface, making it the most accessible position to maintain with the least amount of muscle work needed. For example, in Savasana, all postural muscles can relax because the back surface of the body becomes the base of support (BOS). The lowest center of gravity (COG) is found in Savasana.

Therefore, poses intended to promote relaxation are made such that no muscles are tensed, or there is no need to maintain specific body positions. Since these asanas facilitate easy prana (vital energy) flow, they are necessary for total relaxation. The two popular poses for relaxation are Makarasana and Shavasana [2, 3, 4].

2.3 Meditative asanas

As a practice, meditation includes focused introspection while in one’s physical space. Attaining both mental and physical stability is essential to reach such focus. Therefore, meditative asanas are those poses that guarantee optimal spinal column alignment while providing a broad and stable base of support (BOS). These qualities are essential prerequisites to practicing advanced yogic techniques like Dhyana and Pranayama.

When performing meditative asanas, practitioners attempt to hold the pose for prolonged periods of time, sometimes up to several hours. This long duration makes it easier to conduct longer sessions of higher forms of Yoga, such as Dhyana and Pranayama, which involve withdrawing from outside stimuli and cultivating perfect stillness and comfort, e.g., Padmasana, Sidhhasana [2, 3, 4].

2.4 Phases of asanas

According to Sherrington, posture is intrinsically linked to movement, akin to a shadow following its object. This assertion underscores the notion that motion commences and concludes within a given position. The point of origin for any movement is termed the starting position. Five fundamental starting positions exist, from which all others derive: standing, kneeling, sitting, lying, and hanging. Stability and equilibrium within these positions are upheld by the equilibrium of forces exerted upon the body. Muscular contraction is executed isometrically when it is employed to maintain this equilibrium and stability, signifying that the muscle length remains unchanged during contraction [2, 3, 4].

Each asana commences from a distinct starting point. Every conceivable asana initiates from a specific initial posture and concludes by reverting back to this initial posture. The different phases of asanas are as follows:

1. Starting Position

2. Moving into an asana (dynamic muscle contraction)

3. Holding that asana as per the individual’s capacity (isometric muscle contraction)

4. Moving out of the asana (dynamic muscle contraction)

5. Getting back into the starting position.

Some examples of asansa which have standing as a starting position are TĀḌĀSANA, VṚKṢĀSANA, ARDHA CAKRĀSANA, etc.

Some examples of asansa which have sitting as a starting position are VAJRĀSANA, ARDHA UṢṬRĀSANA, UTTĀNA MANDŪKĀSANA, etc.

Some examples of asansa which have prone lying as a starting position are MAKARĀSANA, BHUJAṄGĀSANA, ŚALABHĀSANA, etc.

Some examples of asansa which have supine lying as a starting position, are SETUBANDHĀSANA, ARDHA HALĀSANA, PAVANA MUKTĀSANA, etc.

3. General guidelines for the practice of yoga asana

The Ashtanga Yoga of Maharshi Patanjali outlines eight branches of yoga; practicing asanas is the third and necessary step in the yoga path. For this reason, it is crucial to understand the concepts of Yama and Niyama before performing any asana [2, 3, 4].

1. Asanas should be performed with individuals advised to seek guidance from a medical professional or therapist, particularly if they have underlying medical conditions.

2. It is essential for the bladder and bowels to be empty before commencing the practice of asanas.

3. The execution of asanas should be characterized by a relaxed demeanor, ensuring stability, comfort, and a sense of effortlessness.

4. The duration of holding the final pose should align with the practitioner’s capabilities, emphasizing individual capacity.

5. Abrupt and forceful movements during transitions into and out of asanas should be avoided to mitigate the risk of injury.

6. Optimal practice entails maintaining each posture for a minimum of 10 seconds or at least three complete breath cycles.

7. Prior knowledge of the indications and contraindications associated with each asana is essential for practitioners to ensure safe and effective practice.

8. A bath is recommended after 20–30 min following the conclusion of a yoga session.

9. Consumption of food is advised only after 20–30 min post-yoga practice, allowing the body ample time to transition and restore equilibrium.

4. Impacts of yogasana on the human body

The human body consists of trillions of cells, which combine to form tissues, and tissues combine to form organs. These organs, in turn, assemble into organ systems, ultimately constituting the entirety of an individual organism. Within the human body, numerous systems operate in harmony to sustain life and overall function. A fundamental grasp of human anatomy and physiology is crucial for comprehending the body’s internal mechanisms and how various yogic practices influence different layers of existence, known as koshas.

Although the term “Yogaasanas” implies movement, it is often mistakenly believed to impact the musculoskeletal system primarily. However, yogic postures exert substantial effects on various vital organs and systems beyond just the musculoskeletal system. These systems encompass the nervous system, musculoskeletal system, respiratory system, cardiovascular system, digestive system, excretory system, reproductive system, lymphatic system, endocrine system, and integumentary system.

5. Biomechanical impact of yogasanas

The musculoskeletal system plays a vital role in maintaining body structure, facilitating movement, and safeguarding essential organs. Engaging in regular practice of Yogasanas is widely acknowledged for its positive impact on musculoskeletal health. Understanding the mechanics behind performing yoga asanas is crucial. Essentially, yoga asanas entail movement, which primarily occurs at the joints due to skeletal muscle contractions along specific planes and axes within the body. Human anatomy recognizes three principal anatomical planes: frontal, sagittal, and transverse, which correspond to forward/backward, side-to-side, and rotatory movements, respectively. Moreover, the range of motion (ROM) in various synovial joints is influenced by multiple factors, including anatomical structure and individual flexibility. Alignment in yoga asanas refers to how body segments are positioned in relation to each other, as each asana imposes its unique physical demands. Optimal alignment entails movement across all three planes and around all three axes of the body. Additionally, the stability of a particular asana hinges on three critical factors: the center of gravity (COG), the line of gravity (LOG), and the base of support (BOS). These elements vary across different asanas, resulting in varying degrees of stability and physical demand.

Properly executed asanas play a pivotal role in preserving musculoskeletal integrity. When performed with correct alignment, Yogasanas contribute to enhancing muscle flexibility and optimizing joint range of motion. These practices facilitate movement across all three anatomical planes and axes, thereby mitigating muscle imbalances resulting from factors such as poor posture, prolonged sedentary behavior, or ergonomic deficiencies in work environments. Regular engagement in Yogasanas also fosters bone health by adhering to Wolff’s Law, which posits that bone formation is directly influenced by mechanical stress and strain. Through weight-bearing Yogasanas, bone strengthening and mineralization are stimulated, thereby enhancing bone density and resilience. These weight-loading practices can mitigate age-related bone loss, bolster bone density, and avert conditions like osteoporosis [5].

When executed with precise alignment, standing asanas preserve the spine’s physiological curvature and enhance posture. Each asana imposes distinct biomechanical demands, resulting in selective stretching of specific muscle groups while concurrently activating others to accommodate increased demand. This dynamic movement creates a symbiotic relationship wherein specific muscles undergo elongation, promoting flexibility, while opposing muscle groups experience intensified activity, fostering tonicity and strength. Consequently, a harmonious equilibrium is sustained between the flexibility and strength of agonist and antagonist muscle pairs during the execution of individual asanas. Yogasanas exhibit promising potential in augmenting core muscle strength in practitioners [6, 7].

Hence, it can be concluded that musculoskeletal ailments and occupational afflictions are increasingly prevalent in modern society, posing significant health burdens. Integrating Yoga into comprehensive treatment strategies can offer substantial benefits for managing and mitigating musculoskeletal disorders. Yoga, a holistic mind-body practice, amalgamates physical postures, controlled breathing, meditation, and relaxation techniques. This multifaceted approach fosters enhancements in flexibility, strength, balance, and somatic awareness, concurrently promoting mental well-being. Moreover, Yoga augments local circulation, facilitating the elimination of metabolic byproducts and oxidative stress, thereby ameliorating discomfort and expediting tissue repair processes. Emphasizing proper joint alignment, Yogasanas cultivate strength within postural musculature by sustaining optimal alignment over extended durations. This methodical approach to alignment and muscular engagement forms a foundational aspect of Yoga practice, contributing to its therapeutic efficacy in addressing musculoskeletal issues [8].

6. Impacts of yogaasana on the respiratory system

Consistent engagement in yogic routines heightens respiratory efficiency, diminishing the susceptibility to respiratory infections, augmenting lung capacity, and refining breathing patterns. The sustained practice of Yoga diminishes the likelihood of respiratory ailments such as asthma and chronic obstructive pulmonary disease (COPD) [6]. Yogic practices enhance various lung volumes and capacities, including tidal volume, vital capacity, maximum ventilator volume, and forced vital capacity. Different types of breathing maneuvers during the practice of asanas exert influence on respiration by voluntary modification of breathing patterns through regulation of higher brain centers. Respiration, involving muscular contraction and thoracic cage movement, is impacted by specific asanas with stretching effects on the chest wall. These postures, such as Tadasana, Trikonasana, Bhujangasana, and Dhanurasana, contribute to the expansion of the chest wall, maintenance of spinal curvature, and correction of postural defects. Consequently, this aligned posture fosters deeper respiration. Yogic practices further augment the vital capacity of practitioners while reducing respiratory rate. This enhancement is facilitated by the expansion of the chest area, leading to increased anteroposterior and vertical dimensions of the thoracic cavity, thereby accommodating more air within the lungs. Isometric contraction of respiratory muscles during yogic techniques enhances muscle strength, particularly in chest muscles like the diaphragm and intercostals. This strengthening effect positively impacts lung function parameters such as forced vital capacity, forced expiratory volume at the end of the first second, maximum voluntary ventilation, peak expiratory flow rate, and breath-holding time prolongation [9, 10]. The practice of asanas enhances circulation, thereby facilitating adequate blood flow to essential organs. Consistent engagement in yogic asanas and pranayamas, as a non-pharmacological intervention for individuals with ailments, holds promise for enhancing pulmonary function overall [11].

7. Impacts of yogasana on the cardiovascular system

Yogic asanas, characterized by dynamic and static postures, exert diverse effects on the cardiovascular system. Emerging research indicates that specific asanas possess the ability to induce relaxation by eliciting reductions in heart rate, blood pressure, and sympathetic nervous system activity. Conversely, vigorous asanas can elevate heart rate and activate the cardiovascular system. Across the spectrum of asana practice, sukshmvayama, the warmup practices consistently promote increased blood flow to the targeted areas. Clinical investigations demonstrate that regular yogic practices contribute to improvements in blood pressure, lipid profile, and overall cardiovascular resilience. Notably, Savasana, characterized by minimal muscle engagement and mental relaxation, facilitates a state of general relaxation. This relaxation response is accompanied by a reduction in muscle tone and a shift toward parasympathetic dominance, resulting in significant reductions in basal heart rate and systemic blood pressure. Engaging in yogasanas fosters enhanced circulation, augments venous return, and elevates cardiac output (including stroke and minute volume). Furthermore, yogic practices contribute to toning cardiac muscles and reducing systolic and diastolic blood pressure, promoting cardiovascular health and function [12, 13]. However, certain asanas have specific contraindications, particularly inverted poses like Sarvangasana, Viparita Karni, Halasana, and Mayurasana. These poses should be avoided or performed under medical supervision by individuals with hypertension.

8. Impact of yogaasanas on the cardiorespiratory performance

The positive effects of yoga asanas on the cardiorespiratory system are rooted in diverse physiological and neurological processes. These include the regulation of the autonomic nervous system, alterations in baroreflex sensitivity, and enhancements in respiratory muscle coordination. A more profound comprehension of these mechanisms offers valuable insights for incorporating yoga asanas into holistic cardiorespiratory rehabilitation and preventive strategies [14].

The consistent engagement in specific yogasanas has been linked to notable enhancements in cardiopulmonary fitness. Asanas demanding prolonged exertion and regulated respiration are observed to augment aerobic capacity and general endurance levels. Moreover, yogic disciplines contribute to improved physical performance across various metrics, encompassing aerobic capacity, anaerobic power, body composition, and cardiovascular endurance [15, 16].

9. Impacts of yogasana on the digestive system

Poses involving abdominal twists can stimulate and massage vital organs such as the liver, pancreas, gallbladder, and various parts of the digestive tract. This manipulation potentially promotes better digestion, enhances nutrient absorption, and may contribute to overall gastrointestinal health [17].

It is widely acknowledged that serotonin, a neurotransmitter crucial for mood regulation, is influenced in part by the digestive tract. Dysfunction of the “gut-brain” axis or enteric nervous system is linked with gastrointestinal disturbances such as irritable bowel syndrome (IBS), alongside mental health disorders like depression and anxiety. Yoga promotes a harmonious interaction between the mind and body, significantly improving digestion and mood regulation [18, 19, 20].

The described concept elucidates how emotional states can influence the functioning of digestive organs, resulting in issues such as acidity, indigestion, and gastric disturbances. Practically all yoga asanas impact the body’s digestive system by enhancing processes such as digestion, absorption, and secretion, as well as relieving constipation, optimizing peristaltic movement, regulating juice secretion, and improving blood circulation to abdominal organs. Furthermore, the abdominal wall provides support to the abdominal viscera, thereby aiding in maintaining the tone of smooth muscles within the viscera. Specific asanas exemplify these effects. Vajrasana, particularly effective post-meal, aids in proper digestion, facilitates the release of Apana Vayu and alleviates indigestion and constipation. Padmasana enhances blood flow in the abdominal region, benefiting internal organs and digestion. Trikonasana massages and tones all internal digestive organs, enhancing appetite and the efficiency of the digestive system. Stress plays a significant role in disrupting digestive function. Yoga practices, encompassing both asanas and relaxation techniques, have been scientifically proven to mitigate stress levels and foster a sense of calmness. This relationship between stress reduction through yoga and its positive impacts on digestion underscores the holistic benefits of yoga for both mental and physical well-being [21].

Certain yogasanas entail controlled movements involving gentle twists, compressions, and stretches, strategically targeting the abdominal organs, including the stomach, liver, and pancreas. These specific movements have been observed to elicit physiological responses that enhance digestive enzyme secretion, facilitate gastric emptying, and improve overall digestive efficiency. Asanas emphasizing forward bends and controlled abdominal contractions have demonstrated the ability to modulate gut motility positively. Regular incorporation of such practices into one’s routine may offer preventive benefits against constipation and promote the maintenance of optimal bowel function. Yoga has garnered recognition as an adjunctive therapy for a spectrum of gastrointestinal disorders, encompassing irritable bowel syndrome (IBS), acid reflux, and inflammatory bowel disease (IBD). Through the utilization of targeted yoga asanas and breathing methodologies, symptomatology associated with these conditions can be mitigated, while concurrently addressing stressors that often exacerbate symptoms. This holistic approach to management holds promises for enhancing the overall quality of life for individuals grappling with gastrointestinal disorders [19, 22].

The enteric nervous system, also known as the intrinsic nervous system, constitutes a fundamental division of the peripheral nervous system responsible for regulating the digestive tract’s function. These mechanisms may include the stimulation of the vagus nerve, modulation of the gut-brain axis, and the relaxation response. Understanding these mechanisms can provide insights into integrating yoga asanas as a complementary approach to digestive health management.

10. Impacts of yogasana on nervous system

Regular engagement in yogic practices exhibits notable benefits for cognitive function, sleep quality, and brain structure. Specifically, the practice of Hatha Yoga appears to be correlated with facilitating neuroplastic changes within executive brain systems, as evidenced by an augmentation in gray matter volume. This consistent yogic regimen is also associated with heightened gamma-aminobutyric acid (GABA) secretion, regulation of dopamine levels, and increased serotonin secretion. A single session of yoga asanas has been demonstrated to elevate the levels of gamma-aminobutyric acid in practitioners. GABA, functioning as a neurotransmitter, induces a state of relaxation by mitigating symptoms associated with stress and anxiety. Prior research has underscored the capacity of yoga asanas to enhance GABA levels, consequently eliciting a relaxed physiological state [22, 23]. Yoga exerts beneficial effects on neurotransmitter levels in practitioners, including the enhancement of dopamine and serotonin. Elevated dopamine levels contribute to reduced risk of Parkinson’s disease and improved coordination. Meanwhile, serotonin serves as a biochemical indicator of happiness, enhancing mood and counteracting depression when levels are sufficient. Yogic practices additionally reduce cortisol levels, a biomarker of stress, and enhance alpha (α) wave activity in electroencephalography, indicating heightened states of relaxation. Furthermore, yoga enhances sleep quality. Notably, yoga practice has been associated with increased levels of Brain-Derived Neurotrophic Factor (BDNF), crucial for adult neurogenesis, as well as oxytocin. These neurochemicals play pivotal roles in cognition, further underscoring the cognitive benefits conferred by yogasana practice [19, 24, 25]. BDNF and serotonin exert regulatory influence over crucial processes in the adult brain, including neurogenesis, synaptic plasticity, and neuronal viability. The practice of yoga exerts multifaceted effects on the autonomic nervous system (ANS), higher cognitive functions, and mental well-being. Clinical studies have provided evidence supporting the capacity of yoga asanas to modulate the ANS, promoting parasympathetic dominance, reducing blood pressure and heart rate, facilitating relaxation, and fostering approach-oriented behaviors [26, 27].

11. Impacts of yogasana on endocrine system

The endocrine system consists of glands that pour their secretion directly into the bloodstream. The hormone is a chemical substance that influences the target cells’ function. They are of two types: water-soluble and fat-soluble. The endocrine system is vital for maintaining homeostasis of the human body, i.e., maintaining a constant internal environment in response to internal and external stressors. The nervous system is also essential to maintain homeostasis and is rapidly acting. However, the endocrine system is slower and has a long-lasting control than the nervous system.

The internal environment is tightly controlled; this reasonably constant state is called homeostasis. When this balance is disturbed in response to various stressors (internal and external), there is a severe risk to the individual’s well-being. Some essential physiological variables maintained within narrow limits by homeostatic control mechanisms are core temperature, body fluids’ pH (acidity or alkalinity), blood glucose levels, etc. Homeostasis is maintained using feedback mechanisms (negative and positive feedback mechanisms). The various endocrine glands are pituitary gland, thyroid gland, parathyroid gland, adrenal gland, pancreas, and gonads.

Yoga fine tunes the different inter-related links of the hypothalamic-pituitary-adrenal (HPA) axis, which helps to keep the mind and body of the practitioner aligned and relaxed and leads to optimal functioning of the endocrine system by reducing the effects of various stressors, which brings about a change in the internal environment of the body. Yogic practices decrease stress by modulating the HPA axis [19]. It regulates the thyroid hormone secretion to maintain balance and metabolism [28].

12. Impact of yogasana on renal physiology

The kidneys play a crucial role in preserving fluid and electrolyte balance, eliminating waste products, and regulating blood pressure. Yogasanas are integral for supporting renal health, as certain poses can enhance blood circulation to the kidneys, potentially improving renal filtration and waste elimination. Consistent practice of specific yoga asanas may influence renal function and filtration rate. Research indicates that yoga practice can positively affect renal parameters, including glomerular filtration rate (GFR) and renal plasma flow (RPF). The mechanisms might entail enhanced vascular endothelial function, modulation of the autonomic nervous system, and decreased oxidative stress resulting from yogasana practice, potentially leading to improvements in renal physiology [29].

13. Impact of yogasana on the reproductive system

The reproductive system is crucial for human reproduction and overall health. Yogasanas have been recognized as a beneficial practice for women’s reproductive health. Specific poses and relaxation techniques may help regulate menstrual cycles, alleviate menstrual pain, and reduce symptoms of premenstrual syndrome (PMS). Additionally, yoga can promote fertility and support women going through various stages of reproductive life. Yogasanas, pranayama, and meditation may have potential implications for male reproductive health. Some studies have shown that regular yoga practice can improve sperm quality, hormonal balance, and overall fertility. This may be due to reduced stress levels, enhanced blood flow to reproductive organs, and improved endocrine function to improve the functioning of the reproductive system [30, 31].

14. Conclusion

This chapter review provides a thorough examination of the profound effects of Yogasana on both the human body and mind. Empirical evidence strongly supports the notion that regular Yogasana practice yields a multitude of physiological, biomechanical, and psychological benefits. Its potential as a therapeutic intervention for enhancing overall well-being and mental health is compelling. However, to fully unlock its therapeutic potential, further research is necessary to uncover the underlying mechanisms and refine its application across diverse clinical contexts. Through continued investigation and refinement, Yogasana stands poised to revolutionize holistic health and wellness practices for generations to come.