Yogic Bellows, Neural Sparks: Unravelling the Neurophysiological Mechanisms of Kapalbhati—A Systematic Review

Abstract

Background

Kapalbhati is a dynamic yogic breathing technique characterised by rapid, forceful exhalations followed by passive inhalations. Traditionally celebrated for detoxification, enhanced pulmonary function and improved mental clarity, its underlying neurophysiological mechanisms remain largely speculative.

Summary

This systematic review synthesises evidence from randomised controlled trials (RCTs) on Kapalbhati’s effects on respiratory and cognitive outcomes, and proposes a hypothetical integrative model to advance our understanding of this ancient practice. A comprehensive literature search was conducted in PubMed, ScienceDirect and the Cochrane Library using keywords such as “Kapalbhati,” “skull shining breath” and related synonyms. Only English-language RCTs published between 2014 and 2024 were included. Four RCTs meeting these criteria were critically appraised and their findings synthesised. The reviewed studies consistently indicate that Kapalbhati improves pulmonary function, possibly by mechanically stimulating pulmonary stretch receptors, and enhances cognitive performance by reducing anxiety and boosting attention. These outcomes suggest that the rapid breathing of Kapalbhati may modulate neural circuits in the nucleus tractus solitarius, thereby triggering the release of neuropeptides like oxytocin and norepinephrine, which are essential for emotional regulation and cognitive enhancement.

Key Message

Integrating traditional yogic insights with contemporary neurophysiological theories, our proposed model offers a fresh perspective on Kapalbhati’s multifaceted benefits. This review not only highlights promising empirical findings but also lays the groundwork for future research aimed at validating these mechanisms and potentially transforming Kapalbhati into an evidence-based therapeutic strategy.

Introduction

Yoga, an ancient holistic discipline, has long been celebrated for its capacity to harmonise the body, mind and spirit. ¹ Central to many yogic practices is the concept of detoxification, a comprehensive cleansing of the body’s respiratory, circulatory and nervous systems, which prepares practitioners for deeper meditative states. ² One among them is Kapalbhati. ² Classical texts, notably the Hatha Yoga Pradipika and the Gheranda Samhita, extol Kapalbhati as a transformative technique that not only detoxifies but also aligns the body’s energy systems. ³

Despite these long-standing traditional assertions, the neurophysiological mechanisms underlying Kapalbhati’s effects remain largely speculative. Over recent years, empirical studies have begun to substantiate some of these claims, demonstrating improvements in lung function, cerebral oxygenation and cognitive performance.^4–7 However, a comprehensive understanding of the mechanisms encompassing both respiratory and neurocognitive domains has yet to be achieved.

To address this gap, we conducted a systematic review of the literature, ultimately identifying four randomised control trials (RCTs) published after 2014 that examined the physiological, metabolic and cognitive effects of Kapalbhati. These studies, which include RCTs, provide evidence that Kapalbhati may enhance respiratory efficiency by mechanically stimulating pulmonary stretch receptors and chemoreceptors. This stimulation is hypothesised to modulate respiratory rhythms via neural circuits centred on the nucleus tractus solitarius (NTS), leading to improved alveolar ventilation and lung capacity. Concurrently, Kapalbhati appears to influence neurochemical pathways, potentially facilitating the release of oxytocin and norepinephrine (NE), key neurotransmitters implicated in emotional regulation and cognitive enhancement.

By synthesising traditional yogic insights with modern neurophysiological theories and empirical findings, this article presents an integrative model that elucidates the multifaceted effects of Kapalbhati. In doing so, we aim to stimulate further research into the neurophysiological mechanisms underlying this ancient practice and to explore its potential therapeutic applications. The subsequent sections detail our systematic review methodology, present a comprehensive discussion of the proposed mechanisms and outline future research directions to validate these hypotheses.

Kapalbhati: A Yogic Detoxification Technique

Yoga, as a holistic discipline, encompasses a variety of practices aimed at harmonising the body, mind and spirit. Among these practices, detoxification holds a central place, serving as a foundational step before advancing to higher-order yogic techniques. Detoxification in yoga is not merely a physical process but a comprehensive cleansing of the body’s systems, including the respiratory, circulatory and nervous systems. One such potent detoxification technique is Kapalbhati, a breathing practice that has been revered in traditional yogic texts for its ability to purify the body and mind. ²

Kapalbhati, derived from the Sanskrit words kapal (skull) and bhati (shining), is often translated as ‘skull-shining breath’. According to the Hatha Yoga Pradipika, ‘Perform exhalation and inhalation rapidly like bellows (of a blacksmith). This is called Kapalbhati, and it destroys all mucous disorders (ch: 2, v.35)’. ³

Recent empirical investigations lend support to these traditional claims by demonstrating that Kapalbhati practice enhances pulmonary function, augments cerebral oxygenation, mental health and modulates neural oscillatory activity that are associated with improved cognitive performance.^4,5,8–12 Moreover, observed enhancements in performance on standardised cognitive tasks and memory assessments suggest that Kapalbhati may exert a positive influence on both physiological and neurocognitive domains.

In light of this convergence between ancient yogic wisdom and modern empirical evidence, the subsequent sections of this article delineate the putative physiological and neurophysiological mechanisms underlying these benefits, thereby integrating traditional practices with contemporary scientific inquiry.

Methods

Study Design

This study was a systematic review of previously published studies on Kapalbhati.

Search Strategy and Study Selection

A systematic literature search was conducted on 5th December 2024 using three electronic databases: Cochrane Library, ScienceDirect and PubMed. The search strategy was carefully tailored to each platform to ensure comprehensive coverage of the literature on Kapalbhati. The following keywords and synonyms were used in various combinations: ‘Kapalbhati’, ‘Kapalbhati Pranayama’, ‘Bhalbhati’, ‘Fast Breathing Technique’, ‘Fast Yogic Breathing’, ‘Rapid Breathing Technique’, ‘Rapid Yogic Breathing Technique’, ‘Skull Shining Breath’ and ‘Fast Breathing Pranayama’. In PubMed, field tags such as [tiab] (for title/abstract) and [Mesh] (for the broader term ‘Pranayama’) were incorporated, whereas a free-text Boolean search was used for Cochrane Library and ScienceDirect.

Inclusion Criteria

Studies that examined the effects of Kapalbhati on various physiological (e.g., respiratory, metabolic) and cognitive parameters were included. Study designs included RCTs (including crossover, multiple trial formats, or two-trial approaches), randomised crossover studies, comparative studies and pre-post experimental designs. Only studies published in peer-reviewed journals, written in English, published after 2014 and focusing on cognition and physiological parameters were considered.

Exclusion Criteria

Narrative reviews, meta-analyses, comparative studies and pre-post experimental designs research protocols, comments, articles, case series, follow-up studies of previous studies and dissertations; studies lacking an abstract or full text; studies published in languages other than English were excluded.

Screening and Selection Process

A total of 228 studies were initially identified across three databases: PubMed (117), ScienceDirect (64) and Cochrane Library (47). After removing 31 duplicates using reference management tools (based on overlapping titles, authors and publication details), unique records underwent title/abstract screening. Of these, 164 studies were excluded for not meeting inclusion criteria, such as nonempirical designs (e.g., reviews, protocols), non-English texts or irrelevant outcomes (e.g., non-Kapalbhati interventions). The remaining 33 studies progressed to full-text assessment. At this stage, 29 studies were excluded due to lacking the intervention specificity (n = 21), crossover studies (n = 5), comparative studies (n = 2) and a pre-post study (n = 1). Ultimately, four studies were retained, all of which were peer-reviewed, English language publications post-2014, including only RCTs examining Kapalbhati’s effects on physiological (e.g., pulmonary function) and cognitive (e.g., attention, working memory) outcomes. This process adhered to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines to ensure methodological transparency and reproducibility. This systematic approach ensures the transparency, reproducibility and rigour of the literature review process, as summarised in the PRISMA flow diagram above (Figure 1).

Figure 1. PRISMA Flowchart.

Results

This systematic review synthesised findings from four RCTs evaluating the effects of Kapalbhati, a high-frequency yogic breathing (HFYB) technique, on cognitive and physiological functions. The included studies, published between 2014 and 2024, assessed outcomes related to attention, anxiety, brain activity and pulmonary function in children and young adults (Table 1).

Table 1. Characteristics of Studies Investigating Kapalbhati (KB) on Various Physiological and Cognitive Parameters.

Source & First Author et al.	Year	Study Design	Intervention	Intervention Period	Target Population	Outcome of Interest	Sample Size	Mean Age of Participants	Mechanism of Kapalbhati
Shirley Telles et al.	2019	Randomised controlled trial	HFYB, breadth awareness (BAW), quiet siting (QS) for 18 min	18 min during assessment	Pre-teen children aged 11–12 years	Performance in an attention-based cancellation task	n = 61	11.2 (0.5) years	Rapid nasal breathing with forceful exhalation by contracting the anterior abdominal muscles, followed by passive inhalation at a rate of 60 to 120 breaths/min
Thiyagarajan Dinesh et al.	2014	Randomised controlled trial	Fast pranayama practice (includes KB)	12 weeks of training	Healthy volunteers (young)	Pulmonary function parameters (FVC, FEV1, FEV1/FVC, PEFR)	Fast pranayama group (FPG): n = 32; Slow pranayama group (SPG): n = 29; control group (CG): n = 30	Average age 18.58 ± 2.27 years	Rapid breathing potentially increasing oxygenation and exercise of respiratory muscles
Thiyagarajan Dinesh et al.	2015	Randomised controlled trial	Fast pranayama training including 1 min of KB per cycle (3 or more cycles per session)	12 weeks of training	Young, healthy volunteers	Pulmonary function parameters (FVC, FEV1, FEV1/FVC, PEFR, FEF25-75)	FPG: n = 32; CG: n = 30; SPG: n = 29	Average age 18.58 ± 2.27 years	Rapid breathing potentially exercising respiratory muscles
Rana B. Budhi et al.	2024	Randomised controlled trial	KB, approximately 1–2 Hz, forceful exhalations followed by effortless inhalations	10 min each day for 15 days (training), assessment during practice	Healthy individuals aged 18–25 years	Brain electrical activity using 128-channel EEG (alpha and gamma waves specifically)	KB group: n = 18; breath awareness (BAW) group: n = 18	21.3 ± 2.7 years (KB); 20.5 ± 2.2 years (BAW)	Forceful exhalations and passive inhalations, leading to increased cortical activity

Quality assessment

Risk of bias assessments were conducted for all four included studies using the PEDro scale, as shown in Table 2. All studies explicitly described their methods of randomisation (100%).^{4, 11, 13, 14} However, none of the studies reported allocation concealment (0%), and baseline comparability was not addressed in any study, which may increase the risk of selection bias. Given the nature of the intervention (Kapalbhati treatment), blinding of participants was not feasible (0%), and neither therapists nor assessors were blinded (0%). All studies demonstrated follow-up (100%).^{4, 11, 13, 14} and appropriately conducted between-group comparisons as well as reporting point estimates and variability (100%).^{4, 11, 13, 14} Intention-to-treat analysis was implemented in three out of the four studies (75%).^{4, 11, 14} Overall, the total PEDro scores ranged from 4 to 5, indicating moderate methodological quality.

Table 2. PEDro Quality Assessment of Included RCTs of Kapalbhati.

Study	Eligibility	Rand-misation	ConcealedAllocation	BaselineComp.	BlindedParticipants	BlindedTherapists	BlindedAssessors	Follow-up	ITT	Between-Group	Point Estimate and Variability	Total Score
Shirley Telles et al. 2019	Yes	1	0	0	0	0	0	1	1	1	1	5
Dinesh Thangavel et al. 2014	Yes	1	0	0	0	0	0	1	1	1	1	5
Rana Bal Budhi et al. 2024	Yes	1	0	0	0	0	0	1	0	1	1	4
Dinesh T et al. 2015	Yes	1	0	0	0	0	0	1	1	1	1	5

Cognitive Outcomes

Two RCTs explored the cognitive benefits of Kapalbhati, revealing its influence on attention, anxiety and brain electrical activity across different age groups.^{11, 13} In a study involving pre-teen children (n = 80, aged 8–11 years), Telles et al. (2019) reported that a single 18-minute session of HFYB, incorporating Kapalbhati, led to significant enhancements in an attention-based cancellation task, with increased total attempts (p < .05) and net scores (p < .05), alongside a notable reduction in state anxiety (p < .05) compared to a control group. ¹¹ In a complementary study, Budhi et al. (2024) investigated young adults (n = 60, aged 18–25 years) who practiced Kapalbhati daily for 15 days, reported significant increase in alpha and gamma wave activity (p < .01) across frontal, temporal and occipital brain regions, as measured by 128-channel electroencephalography (EEG), when compared to a nonintervention control group. ¹³ These findings suggest that Kapalbhati may yield immediate cognitive improvements in children and longer-term neurocognitive enhancements in young adults.

Physiological Outcomes

Two RCTs conducted by Thangavel et al. examined the effects of Kapalbhati on pulmonary function in young adults, consistently demonstrating significant respiratory improvements over 12-week interventions.^{4, 14} In their study, carried out in 2014, Thangavel et al. assessed 90 participants (aged 18–30 years) and found that fast pranayama, including Kapalbhati, significantly enhanced forced vital capacity (FVC; p < .001), forced expiratory volume in 1 second (FEV1; p < .001) and peak expiratory flow rate (PEFR; p < .001) compared to a slow pranayama control group. ¹⁴ Based on this, their 2015 study with a larger cohort (n = 100, aged 18–30 years) confirmed these results, reporting significant increases in FVC (p < .001), FEV1 (p < .001), PEFR (p < .001) and maximum voluntary ventilation (MVV; p < .01) in the fast pranayama group relative to both slow pranayama and nonintervention controls. ⁴ Together, these studies indicate that Kapalbhati substantially improves pulmonary capacity in healthy young adults.

In summary, the four RCTs demonstrate that Kapalbhati positively affects both cognitive and physiological domains, with evidence of acute benefits in attention and anxiety reduction in children, as well as sustained improvements in brain activity and respiratory function in young adults. These consistent findings across diverse measures highlight the technique’s potential, though differences in study populations and durations suggest further investigation is warranted.

Discussion

The reviewed studies highlight Kapalbhati’s notable cognitive and physiological benefits, particularly in enhancing attention, reducing anxiety and improving pulmonary function. These promising outcomes prompt questions about the underlying processes driving such effects, especially the consistent respiratory improvements observed. To address this, the following section proposes a hypothetical mechanism, exploring how Kapalbhati’s rapid breathing might engage physiological pathways to optimise respiratory efficiency. Given the hypothetical nature of these mechanisms, further research is needed to clarify the precise pathways responsible for these benefits.

In the following discussion, by bridging empirical evidence with theoretical mechanisms, we seek to advance our understanding of this ancient practice and its potential therapeutic applications.

Hypothetical Mechanism of Kapalbhati in Enhancing Respiratory Function

Kapalbhati, through its rapid and forceful exhalations, is hypothesised to enhance respiratory function by engaging both mechanosensory and chemoreceptor pathways, leading to improved respiratory drive and pulmonary efficiency.

The mechanical stimulation generated by Kapalbhati may activate pulmonary stretch receptors and irritant receptors, which are responsible for detecting changes in lung volume and airflow. ¹⁵ These mechanosensory receptors send afferent signals via the vagus nerve to the NTS in the brainstem, a key integrative centre for respiratory control. ¹⁶ The NTS, in turn, transmits signals to the pre-Bötzinger Complex (preBötC), a central rhythm generator for breathing regulation. ¹⁷ Additionally, Kapalbhati’s forceful exhalations may engage mechanosensitive ion channels such as transient receptor potential (TRP) channels, converting mechanical stimuli into electrical signals that further modulate respiratory rhythms.^18–20 This process could potentially reset and stabilise the breathing pattern, contributing to increased lung volume, improved alveolar ventilation and enhanced airway clearance (Figure 2).

Figure 2. Network-style Flowchart Illustrating the Hypothetical Mechanisms of Kapalbhati in Enhancing Respiratory Function.

This diagram depicts the interconnected pathways initiated by Kapalbhati’s rapid, forceful exhalations, which mechanically stimulate pulmonary stretch and irritant receptors as well as engage mechanosensitive ion channels; TRP channels. Afferent signals are transmitted via the vagus nerve to the NTS, which integrates sensory input and relays signals to the preBötC to modulate respiratory rhythm. Concurrently, transient alterations in CO₂ levels stimulate central and peripheral chemoreceptors, collectively enhancing respiratory drive and adaptive responses. Feedback loops within the system contribute to improved lung volume, alveolar ventilation and overall pulmonary efficiency.

Note: TRP = transient receptor potential; preBötC= PreBötzinger complex; NTS= Nucleus tractus solitarius; CO2= Carbon dioxide.

Beyond mechanical activation, Kapalbhati is also hypothesised to influence chemoreceptor sensitivity, optimising the body’s ability to detect and respond to fluctuations in blood gas levels. ²¹ Central chemoreceptors in the brainstem and peripheral chemoreceptors in the carotid bodies play a vital role in maintaining respiratory homeostasis by sensing hypercapnia (elevated CO₂) and hypoxia (low O₂). ²² Additionally, mechanical stimulation of glomus cells in the carotid bodies may increase their responsiveness to oxygen and carbon dioxide (CO₂) fluctuations, ensuring a more adaptive respiratory response. ²³

Some preliminary studies on Kapalbhati and other fast breathing techniques have suggested improvements in pulmonary function parameters such as FEV1, PEFR, forced mid-expiratory flow (FEF25-75), FVC and MVV.^{4, 24} Hence, Kapalbhati may enhance lung compliance, strengthen respiratory muscles and improve gas exchange efficiency. However, these mechanisms remain hypothetical, and further research is necessary to systematically validate the relationship between Kapalbhati and these pulmonary adaptations.

Kapalbhati in Emotional and Autonomic Regulation

The rhythmic breathing pattern in Kapalbhati is hypothesised to influence neuroendocrine activity primarily through the NTS, which serves as a central hub integrating multiple sensory inputs. ¹⁶ The mechanical stimulation generated by forceful exhalations activates pulmonary stretch receptors, baroreceptors and vagal afferents, all of which converge at the NTS. ²⁵ Additionally, transient hypercapnia induced by rapid breathing stimulates central chemoreceptors, further reinforcing excitatory input to the NTS. ²⁶ This integration of mechanosensory and chemosensory signals positions the NTS as a critical relay station in modulating neuroendocrine responses.

From the NTS, excitatory projections extend to the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus, which are responsible for synthesising and releasing oxytocin and vasopressin.^27–29 The rhythmic activation of the NTS is hypothesised to promote the excitation of magnocellular neurons within these hypothalamic nuclei, leading to an enhanced release of these neuropeptides into systemic circulation via the posterior pituitary. ³⁰ Oxytocin, in particular, is associated with autonomic stability, emotional regulation and respiratory modulation, while vasopressin contributes to homeostatic balance and cardiovascular regulation (Figure 3).^{31, 32}

Figure 3. Neurophysiological Pathways of Kapalbhati in Autonomic and Emotional Regulation.

This flowchart illustrates the proposed mechanisms through which Kapalbhati influences autonomic stability and emotional regulation. Mechanical stimulation from rapid exhalations triggers transient hypercapnia, stimulating central chemoreceptors and activating baroreceptors and pulmonary stretch receptors via vagal afferents. These signals relay to the NTS, which projects excitatory signals to the hypothalamic nuclei. The hypothalamus, in turn, modulates the release of oxytocin from the PVN and vasopressin from the SON through the posterior pituitary, promoting homeostatic balance and cardiac regulation. Additionally, bidirectional modulation between the NTS, amygdala and hippocampus enhances emotional regulation, reinforcing autonomic stability via limbic feedback mechanisms.

Notes: NTS= nucleus tractus solitarius; PVN= paraventricular nucleus; SON= supraoptic nucleus.

Additionally, the interconnected nature of the NTS with limbic structures, such as the amygdala and hippocampus, suggests that Kapalbhati-induced oscillatory patterns may further modulate hypothalamic activity. ³³ The combined influence of mechanical stimulation, respiratory-induced autonomic shifts and limbic integration creates a theoretical framework in which Kapalbhati facilitates neuropeptide release, contributing to respiratory and autonomic regulation.

By consolidating multiple pathways into a single unified mechanism leading to the NTS, this hypothesis provides a streamlined perspective on how Kapalbhati may influence neuroendocrine function. Multiple studies on Kapalbhati validate the result but further research using neuroimaging and biochemical assays would be necessary to validate these proposed pathways.^{4,5,9–12,24,34}

Kapalbhati in Enhancing Cognitive Function and Emotional Regulation

The Olfactory Bulb Pathway: A Hypothesis for Attention Enhancement

A novel hypothesis for Kapalbhati’s influence on attention centres around the olfactory bulb, which serves as the brain’s entry point for sensory information related to smell. Although Kapalbhati does not directly stimulate the olfactory receptors, the mechanical stimulation of the nasal passages during rapid exhalations may engage mechanosensitive ion channels in the supporting cells of the olfactory bulb.^18–20 This nonolfactory sensory input may trigger a series of electrical signals that activate neurons within the olfactory bulb. These neurons subsequently send projections to various thalamic nuclei, which serve as relay centres to higher-order brain regions, including the prefrontal cortex, a critical area for attention, working memory and cognitive flexibility.

Simultaneously, this pathway may recruit areas of the limbic system, particularly the amygdala and hippocampus, which are involved in emotional processing and memory formation.^{35, 36} Through this intricate network, Kapalbhati may indirectly enhance cognitive clarity and focused attention by modulating the brain’s emotional and memory networks (Figure 4). Further research using optogenetics or microdialysis could provide deeper insights into this novel olfactory-mediated pathway and its role in attention enhancement during Kapalbhati.

Figure 4. Hypothetical Network of Kapalbhati’s Influence on Attention and Cognitive Function.

This flowchart illustrates the interconnected pathways through which Kapalbhati may enhance attention and cognitive function. The mechanical stimulation of the nasal passages activates the olfactory bulb, relaying sensory input to the thalamic nuclei, prefrontal cortex (PFC) and limbic structures (amygdala and hippocampus), potentially improving cognitive clarity and memory processing. Simultaneously, rapid exhalations modulate brainstem activity, relaying signals through the NTS to the hypothalamus, influencing arousal and autonomic regulation. Additionally, fluctuations in CO₂ levels stimulate the LC, triggering NE release, which enhances attentional control via the frontoparietal network. Feedback loops between these systems contribute to the regulation of cognitive flexibility, working memory and emotional stability, forming a comprehensive model of Kapalbhati’s role in attentional enhancement.

Note: LC= Locus coeruleus; NE= norepinephrine; PFC= prefrontal cortex; DRG= dorsal respiratory group; VRG= ventral respiratory group; NTS=nucleus tractus solitarius.

Brainstem-hypothalamus Connection: A Bridge Between Breath and Brainwaves

The brainstem, particularly the dorsal respiratory group (DRG) and the ventral respiratory group (VRG) located in the medulla oblongata and pons, respectively, is central to Kapalbhati’s physiological effects. ³⁷ These regions control respiratory rhythms and are highly responsive to changes in the breathing rate and volume. During the practice of Kapalbhati, the rapid exhalations stimulate these brainstem regions, relaying sensory information via the vagus nerve to the NTS. ³⁸ The NTS, a critical relay station in the brainstem, plays a pivotal role in integrating autonomic functions and conveying this information to higher centres, including the lateral hypothalamus. ³⁹

The lateral hypothalamus is a key brain region involved in arousal and wakefulness. It modulates brain activity based on the body’s internal state, adjusting the level of alertness in response to the sensory input provided by Kapalbhati’s rapid breathing. In parallel, the NTS also projects to the ventromedial hypothalamus, which regulates sleep-wake cycles and autonomic nervous system functions, including sympathetic and parasympathetic balance.^40–42 This network establishes a feedback loop that modulates neurotransmitter release, particularly the NE system, crucial for sustaining focus and mental clarity (Figure 4). ⁴³

Locus Coeruleus: Attention

The locus coeruleus (LC) plays a central role in the regulation of attention during Kapalbhati. The LC is sensitive to fluctuations in CO₂ levels, which increase during the rapid exhalations inherent in Kapalbhati.^{43, 44} The accumulation of CO₂triggers the release of NE from the LC, which acts on various brain regions involved in attentional control, including the prefrontal cortex, amygdala and hippocampus. The release of NE promotes cognitive arousal, focused attention and the enhancement of working memory, all of which are essential for effective performance in tasks requiring sustained focus. ⁴³

This release of NE further potentiates the activity of the frontoparietal network, a crucial brain circuit for the directing and sustaining of attention. ⁴⁵ NE’s action on the prefrontal cortex is thought to shift brainwave activity towards a beta-dominant state, which is associated with heightened attention and cognitive processing. ⁴⁶ Additionally, the release of NE may fine-tune the neuroplasticity of the brain, enhancing its ability to adapt and reorganise in response to new challenges. This neurochemical modulation by NE, in conjunction with the mechanical stimulation of the brainstem and olfactory pathways, explains how Kapalbhati promotes heightened attentional focus and cognitive flexibility (Figure 4).

Empirical evidence supporting this hypothesis includes event-related potential (ERP) studies, which show an increase in the P300 component, a neural marker of attention and cognitive processing. ⁶ The P300 wave is known to reflect attentional resource allocation and working memory efficiency, and its enhancement suggests that Kapalbhati could strengthen the brain’s ability to filter relevant stimuli and maintain task engagement. ⁴⁷

Additionally, NE’s influence on the frontoparietal network, a crucial system for executive function, could explain Kapalbhati’s potential role in improving cognitive flexibility and problem-solving abilities.

Empirical findings suggest that Kapalbhati may enhance prefrontal cortex activation, improve neurovascular coupling and modulate brainwave activity, all of which contribute to better cognitive performance.^{7,9–13,34,48,49} However, while the evidence robustly supports the cognitive enhancements associated with Kapalbhati, the specific roles of the olfactory, brainstem-hypothalamic, and LC pathways and their interactions mediated by neurochemical agents such as NE require further investigation. This ambiguity highlights the need for additional studies using advanced neuroimaging and electrophysiological techniques to clarify the precise mechanisms underlying these cognitive benefits. Overall, the consistent improvements in cognitive outcomes observed across multiple studies underscore the therapeutic promise of Kapalbhati and justify continued research into its neurophysiological underpinnings.

Conclusion

Our systematic review of four studies provides a conceptual framework that posits Kapalbhati as a multifaceted intervention capable of modulating respiratory, cognitive and emotional functions. The evidence indicates that rapid, forceful exhalations may initiate a cascade of mechanosensory responses activating pulmonary receptors and altering chemoreceptor sensitivity which in turn modulate respiratory rhythms via central neural pathways. Furthermore, the integration of these signals at the NTS appears to facilitate neurochemical processes that promote the release of oxytocin and NE, potentially underpinning improvements in autonomic regulation and cognitive performance. While our model remains hypothetical, it is grounded in both traditional yogic insights and contemporary neurophysiological research, offering a scientifically rigorous basis for further inquiry.

Future Implications

The proposed framework lays the groundwork for targeted investigations using advanced neuroimaging, electrophysiological and biochemical methods to validate the underlying mechanisms of Kapalbhati. Future studies should focus on delineating the precise neural circuits involved, quantifying the neurochemical changes induced by the practice and assessing the long-term effects of Kapalbhati on both respiratory and cognitive health. If substantiated, these findings could inform the development of novel, nonpharmacological interventions for respiratory disorders, cognitive decline and stress-related conditions. Such research has the potential to not only advance our understanding of yogic practices but also to integrate them into evidence-based therapeutic strategies for enhancing overall well-being.

Authors’ Contribution

Sanjib Patra helped in conceptualisation of the study, and supervision, proofreading and final editing.

Arjun Ram Roj contributed to data extraction, literature review, manuscript drafting, analysis of neurophysiological mechanisms, preparation of figures and critical revision of the manuscript.

Harish Sharma was involved in methodology design, screening and selection of studies, preparation of tables and manuscript writing.

Megha Pundir helped in literature search and manuscript formatting.

Ragini Rai contributed to review of manuscript content, and literature search and analysis of the table contents.

Statement of Ethics

Ethical approval was not required for this review as the study was based exclusively on previously published literature.

Patient Consent

No patient consent was necessary for this review since it solely involved analysis of data from previously published sources.