Impact of Yoga Intervention on Pulmonary Functions in Young Nonhypoxemic Stable Chronic Obstructive Pulmonary Disease Patients at a Tertiary Care Center

Abstract

Introduction:

Persistent respiratory symptoms and airflow limitation characterize chronic obstructive pulmonary disease (COPD). It is a progressive condition characterized by pulmonary and systemic inflammation, leading to numerous extrapulmonary consequences. This study aimed to evaluate the effect of yoga on pulmonary function in young, nonhypoxemic, stable patients with COPD at a tertiary care center.

Methods:

An intervention study was conducted in the Department of Physiology and Medicine at RUHS CMS and its associated hospitals, Jaipur. A total of 120 subjects were recruited. The cases (Group A) were selected according to the Global Initiative for Obstructive Lung Disease (GOLD) classification. GOLD stage 1 and 2 patients were confirmed by spirometry. All included COPD patients were referred for intervention through asanas and pranayama at a yoga center under the supervision of a certified yoga instructor, for a 45-min session, 6 days a week, and over 3 months.

Results:

Intragroup comparison from baseline and after 3 months intervention in study group showed a significant improvement with weight (P < 0.05), body mass index (BMI) (P < 0.05), forced expiratory volume in the first second (FEV1) (P < 0.05), forced vital capacity (FVC) (P < 0.05), ratio of FEV1/FVC (P < 0.05), slow vital capacity (P < 0.05), and maximal voluntary ventilation (MVV) (P < 0.05) as compared to control.

Conclusion:

Yoga intervention is a beneficial nonpharmacological therapy for young, stable COPD patients, as it improves pulmonary function parameters and reduces BMI through weight loss. Yoga improves blood circulation and enhances tissue perfusion, which in turn increases respiratory muscle strength and helps open blocked airways in patients with COPD. CTRI No: CTRI/2024/07/0698.

Introduction

Persistent respiratory symptoms and airflow limitation characterize chronic obstructive pulmonary disease (COPD).[1] It is a progressive condition characterized by pulmonary and systemic inflammation, as well as numerous associated extrapulmonary complications.[2] Lung function continues to decline with age, and exacerbations may become life-threatening, more frequent, and with complications.[3]

According to a study, the overall prevalence of COPD in people aged 40 years and older was 12.64% and 7.38% based on fixed ratio and lower limit for normal criteria, respectively. The most common stage of COPD was Stage II, with a prevalence of 50.46%.[3] It is the second most prevalent cause of noncommunicable disease-related deaths after road traffic accidents in India, with the age-specific prevalence of COPD increasing rapidly after the age of 30 years.[4]

A wide range of comorbidities and risk factors are associated with the disease, including smoking, genetics, infections, malnutrition, ageing, asthma, occupational exposures, indoor and outdoor air pollutants, and low socioeconomic status.[5] According to the World Health Organization, modifiable risk factors are strongly associated with increased mortality in asthma and COPD. These factors include tobacco smoking habits, indoor air pollution from biofuels, urban outdoor air pollution, occupational factors, exposure to respiratory allergens, and ambient particulate matter.[6] A persistent productive cough is a common symptom of COPD. Patients with COPD most often present with their first acute exacerbation at an advanced stage. Symptoms typically do not occur until the forced expiratory volume in the first second (FEV1) is approximately 50% of the predicted standard value.[7]

COPD is an example of a lifestyle-related illness similar to cardiac diseases, type 2 diabetes, secondary hypertension, osteoporosis, and depression, which can be prevented and controlled through the adoption of healthy lifestyle habits such as yoga. Lifestyle modifications encompass six key pillars: Healthy eating, tobacco cessation, substance control, improved sleep, stress management strategies, social connections, and regular physical activity. In addition to being noninvasive and having a relatively low cost, lifestyle interventions have a positive impact on physiological, metabolic, psychological, and social aspects of health.[8] Daily physical activity of patients with COPD is reduced in the early phases of the disease compared to healthy age-matched controls and worsens over time, with significant consequences.[9]

Yoga is a psychosomatic practice, and its effects are beyond physical attributes. While performing the posture, focus on being aware of the movement, stability, and synchronized breathing. The awareness of every breath is a perception of control over breathing, which is vital for adults living with COPD who encounter breathlessness, leading to functional disability and anxiety.[10] Yogic asana and pranayama have been shown to improve breathing, respiratory functions, and vital capacities as mentioned in previous studies.[10,11,12] It has been demonstrated that yoga therapy has a positive effect on lung function and exercise capacity when used as an adjunct to a pulmonary recovery program for patients with COPD.[13] Behera observed a significant beneficial impact of yoga on respiratory function.[14] Udupa et al. also observed that after yoga intervention, lung function improved.[15] There are only a few studies that examine the effects of yoga in young nonhypoxemic stable COPD patients. This study aimed to assess lung function by spirometry in non-hypoxemic, stable, relatively younger age group COPD patients.

Methods

This study was conducted at the Department of Physiology and Respiratory Medicine, RUHS College of Medical Sciences. After obtaining approval from the institutional ethics committee (EC-P-35-23/2024), subjects were recruited from February 2024 to April 2024. A total of 120 participants were recruited from the medicine outpatient department, divided into a study group and a control group. The sample size was calculated at a 95% confidence level, an Alpha error of 0.05, and an absolute allowable error of 5%.[15]

Screening of subjects

All clinically diagnosed nonhypoxemic, stable COPD patients with SpO₂ > 90% and Stages 1 and 2 according to the global initiative for obstructive lung disease (GOLD) classification, aged 30–50 years of either sex, were included in this study.[16,17]

According to the GOLD 2023 report, lungs continue to grow and mature until approximately 30 years of age, at which point lung function reaches its peak. The report also uses the term young COPD to describe COPD in individuals aged 20–50 years.[18] Age-matched healthy volunteers from the society served as the control group. Study subjects with lung disease other than COPD were excluded from the study. Participants who had a history of obstructive sleep apnea were excluded from this study by asking them about their sleeping pattern, excessive daytime sleepiness, or snoring or complaining of headache following nocturnal oxygen therapy. All study subjects were informed about the nature and purpose of this study through a participant information sheet, and written informed consent was obtained from all subjects who fulfilled the inclusion criteria.

Outcome assessment

Sociodemographic data, including age, gender, residence, socioeconomic class, occupation, and education of the subjects, as well as anthropometric data, such as weight, height, body mass index (BMI), and vital parameters (Pulse, blood pressure, temperature, respiratory rate, and SpO2) of all study participants were recorded. Spirometric indices in the form of FEV1, forced vital capacity (FVC), and the ratio of FEV1/FVC, slow vital capacity (SVC), and maximum voluntary ventilation (MVV) (FEV1, FVC, FEV1/FVC, SVC, and MVV) were recorded at baseline and after 3 months of yoga intervention.

Procedure

Standardized spirometry was performed in both the study and control groups using the Spiro-tech of Clarity with Model No. ST-TGSA-0026 is a portable spirometer designed for use with a laptop or computer, operating through a USB port at baseline and after 3 months of intervention. Before performing spirometry, subjects’ identification, age, and sex were verified, and their height and weight were measured. Instructions and demonstrations of the test to subjects on correct posture, including sitting upright with feet flat on the floor, legs uncrossed, a slightly elevated head, rapid and complete inhalation, positioning of the mouthpiece, and forceful exhalation, were thoroughly explained before the maneuver. All participants were advised to wear loose clothes and continue their regular medication as prescribed by their Physician. After every 10^th patient, the spirometry test equipment was calibrated according to a guideline from the Association for Respiratory Technology and Physiology.[19] As the American Thoracic Society recommended, spirometric indices are calculated based on the three technically satisfactory FEV1, FVC, SVC, and MVV performances. The blood oxygen level is measured with an oximeter. The BMI was calculated using the formula weight/height² (Kg/m²) with the weight and height values. A standard stadiometer measures the subject’s height to the nearest 0.1 cm. Weight is calculated using a standardized weighing scale with the subject in regular clothing. The reading is to be rounded to the nearest 0.1 kg. Sociodemographic data, vital parameters, and spirometric data were recorded at baseline and after 3 months.

Intervention

All COPD patients were advised to continue their current medicines as prescribed by their physician, and the benefits of yoga were explained to them before referring them to a yoga center. The first 4 weeks of yoga practice were held at the yoga lab at RUHS College of Medical Sciences under the supervision of a yoga instructor, providing a structured and supportive environment for learning. The certified yoga instructor explained and demonstrated all yoga asanas and postures in accordance with the Ayush guidelines [Table 1].[20]

Table 1.

Yoga protocol[20]

Practices		Name of practice		Duration (min)
Starting		Prayer		1
Loosening practices (Suksma Vyayama/CalanaKriya)		Neck bending, shoulder movement, trunk movement, knee movement		6
Yoga practices
Standing Asanas		Mountain (Tadasana), Pada-hastasana (Hands to the feet posture), Trikonasana (Triangle posture), Vrikshasana (Tree posture), ArdhaChakrasana (Half Wheel Posture)		7
Asanas performed in sitting posture		Bhadrasana (Firm posture), ArdhaUshtrasana (Half camel posture), Sasakasana (Hare posture), Vakrasana (The seated twist posture), Vajrasana (Diamond posture), Ushtrasana (Camle posture), UtthanaMandukasana (Stretched up-frog posture)		8
Asanas performed while lying on the stomach		Bhujangasana (Cobra posture), Makarasana (Crocodile posture), Shalabhasana (Locust posture)		3
Asanas performed while lying on the back		PawanaMuktasana (Wind releasing posture), Setubandhasana (Bridge posture), Uttanapadasana (Raised leg posture), ArdhaHalasana (Half plough posture), Shavasana (Corpse posture)		6
Kriya		Kaphalabhati (The shining skull practice)		2
Pranayama		Anuloma Viloma Pranayama (The alternate nostril breathing) (5 rounds), Bhramari Pranayama (BhramariRechaka) (The Bee sound breathing), Ujjayee Pranayama (The Hissing breathing)		6
Dhyana		The meditation		5
Closing		Sankalp/Shanti patha		1
Total duration				45

Intervention group participants were instructed to attend a 45-min session, 6 days a week, for 3 months. During asana practices, the trainer emphasized that patients should pay attention to their breathing patterns and be mindful of their bodies. For the next 8 weeks, study participants were advised to continue the same yoga intervention online in their homes, by providing a yoga video clip to help them comply more effectively and allowing them to integrate the practice into their daily lives. The yoga asanas were supervised online using Google Meet. As part of our monitoring, we sent daily text messages to the subjects and made weekly phone calls to them. Compliance was verified by reviewing the diaries during the follow-up visit. Subjects were asked to report any side effects they experienced while performing yoga, such as palpitations, anxiety, pain, soreness, or muscle injury. Yoga was suspended for them for a week, and they underwent a routine physical examination and blood investigations. For surveillance purposes, we conducted telephone chats with the subjects. No intervention was given to the control group. Monitoring of all progress was done by the research team, including the principal and co-investigator. Follow-up of study participants was conducted 3 months after the intervention.

Statistical analysis

Recorded data were analyzed and compared at baseline and after 3 months of yoga intervention. Intragroup comparison was done using a paired t-test, and intergroup comparison was done using an unpaired t-test. Continuous variables were expressed as percentages, and descriptive values were expressed as mean ± standard deviation (SD).

Results

Figure 1 depicts the comparison of sociodemographic variables between the two groups. Age-matched healthy subjects served as the control group. The mean age of the study group was 45.95 ± 4.13, and in the control group, it was 38.65 ± 6.87 (mean ± SD). The study group consisted of 60% males and 40% females (n = 60), whereas the control group consisted of 58.3% males and 41.7% females (n = 60). In the study group (n = 60), 33.3% of the subjects were from rural areas, and 66.7% were urban residents. In the control group (n = 60), 15% of the subjects were from rural areas, and 85% had residences in urban areas. The mean BMI in the study group was 22.40, with a SD of ± 2.87. In the control group, it was reported as 24.19 ± 2.72 at baseline. The mean height in the study group was 1.61 ± 0.082 m and 1.63 ± 0.080 m in the control group. The study group comprised 80% married individuals, 1.7% unmarried individuals, and 18.7% widowed individuals. In the control group, 85% were married, 11.7% were unmarried, and 3.3% were widowed. Economic classes, according to the Modified Kuppuswamy scale, show 1.7% in the upper middle class, 55% in the lower middle class, and 43.3% in the upper lower class among study group subjects, compared to 20% in the upper middle class, 23.3% in the lower middle class, and 56.7% in the upper lower class among the control group.

Figure 1.

Distribution of socio-demographic variables among study participants

After 3 months of yoga intervention, the study group showed significant decreases in weight (P < 0.05), BMI (P < 0.05), FEV1 (P < 0.05), and FEV1/FVC (P < 0.05) compared to the control group [Table 2].

Table 2.

Study variables at baseline and 3 months in the study and control groups

Variable		Groups		Baseline (mean±SD)		3 months (mean±SD)		Significant (two-tailed)
Weight (kg)		Control		64.93±10.13		65.0±9.79		0.532
		Study		58.73±10.72		58.05±10.14		0.000*
		Control versus Study (P)		0.001		0.001
BMI (kg/m2)		Control		24.13±2.67		24.16±2.56		0.449
		Study		22.40±2.88		22.16±2.67		0.000*
		Control versus Study (P)		0.001		0.000
FEV1 (L/s)		Control		2.29±0.53		2.28±0.53		0.031
		Study		1.61±0.38		1.85±0.40		0.000*
		Control versus Study (P)		0.000		0.000
FVC (L)		Control		2.74±0.55		2.76±0.56		0.435
		Study		2.43±0.53		2.77±0.55		0.000*
		Control versus Study (P)		0.002		0.986
FEV1/FVC (%)		Control		82.63±4.17		82.40±4.14		0.091
		Study		66.11±2.68		67.08±3.18		0.000*
		Control versus Study (P)		0.000		0.000
SVC (L)		Control		2.88±0.51		2.86±0.50		0.07
		Study		2.59±0.56		2.90±0.55		0.000*
		Control versus Study (P)		0.004		0.681
MVV (L)		Control		105.58±24.62		104.52±24.04		0.000
		Study		96.25±15.56		105.54±14.84		0.000*
		Control versus Study (P)		0.015		0.779

BMI: Body mass index, FEV₁: Forced expiratory volume in 1 s, FVC: Forced vital capacity, SVC: Slow vital capacity, MVV: Maximal voluntary ventilation, SD: Standard deviation

Discussion

The present study assessed the impact of a 3-month yoga intervention on pulmonary function in stable COPD patients (GOLD Stages 1 and 2) without hypoxemia. In this study, the proportion of stable COPD patients was 45%, which is similar to a previous study.[21] The results demonstrated significant improvements in all spirometric indices, including FEV1, FVC, FEV1/FVC ratio, SVC, and MVV, along with a significant reduction in BMI in the study group compared to the control group [Table 2]. These improvements suggest that yoga may enhance pulmonary function and overall respiratory health in individuals with early-stage COPD. In the study group, all variables decreased after a 3-month follow-up.

In the present study, FEV1 improved significantly after 3 months of yoga intervention. This aligns with the findings of Prasad et al., who observed similar improvement in FEV1 after 3 months of yoga intervention in COPD patients.[22] Singh et al. also reported significant improvements in FEV1 following yoga training in COPD patients.[23] Whereas, Gupta et al. reported that pranayama can improve COPD patient’s subjective experiences of health, disease severity, and functional status without significantly improving FEV1, due to airflow limitation is not totally reversible but usually progressive.[24] Similarly, FVC showed a significant increase in the present study, which is consistent with the findings of Archoudane et al., who reported improved FVC in the yoga group.[25] Contrarily, Zhu et al. reported no significant change in FVC after yoga intervention in the study group.[26]

Furthermore, the FEV1/FVC ratio improved significantly in this study, indicating a reduction in airway obstruction. This observation corroborates findings by Udupa et al. and Singh et al., who noted similar increases in this ratio following yogic breathing and posture practices.[15,23]

SVC and respiratory muscle efficiency also improved significantly in the yoga group. Udupa et al. observed improved static lung volumes, including SVC, with yoga-based respiratory training.[15] In addition, MVV is an index of respiratory muscle endurance, and ventilatory capacity increased significantly in the present study. Thokchom et al. similarly demonstrated improved MVV after yoga training, attributing it to enhanced thoracoabdominal coordination and reduced respiratory fatigue.[27]

The observed physiological improvements can be explained by multiple mechanisms [Figure 2]. Yoga promotes diaphragmatic breathing, enhances respiratory muscle strength, and increases lung compliance. Breathing practices such as pranayama help open obstructed airways and reduce bronchial resistance, which is particularly beneficial in COPD.[28,29] Yoga also shifts autonomic balance toward parasympathetic dominance, reducing sympathetic tone and bronchoconstriction.[30] Moreover, it reduces systemic inflammation; studies have shown reductions in inflammatory markers, such as high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), after regular yoga practice – markers implicated in the pathophysiology of COPD.[31] Collaboration among these parameters in future studies may improve the study’s outcomes.

Figure 2.

Mechanism related to the effect of yoga on chronic obstructive pulmonary disease

Yogic asana and pranayama have been shown to slow down breathing at rest, increase vital capacity, enhance maximal voluntary ventilation, breath-holding time, maximal inspiratory pressure, and maximal expiratory pressure.[10] Yoga deep-breathing techniques, combined with chest wall expansion, improve thoraco-abdominal movement.[11] The use of oxygen increases during pranayama.[12]

In addition, the improved BMI observed after the intervention likely contributed to better pulmonary function. Excess weight can restrict diaphragmatic excursion and reduce lung volumes; hence, weight reduction through yoga could improve ventilatory mechanics.[32]

Limitations of study

The sample size was relatively small and limited to a single center, which may affect the generalizability of the results to broader COPD populations. In interventional studies, the required sample size is primarily determined by the expected effect size, variability of the outcome measure, significance level (α), and desired statistical power (1−β). A priori calculation based on these parameters ensures adequate power to detect clinically meaningful changes and to generalize the results to a wider population. We agree that a larger sample would strengthen the findings. Using FEV₁ change (baseline to 3 months) as the primary outcome and conservative assumptions (α =0.05, 90% power, effect size d = 0.40, 20% attrition), a future confirmatory study would require approximately 165 participants per group (total 330) to improve robustness and generalizability.

Second, the study included only patients with stable COPD in GOLD Stages 1 and 2, without hypoxemia, thereby limiting the applicability of findings to patients with more advanced disease. Third, study participants were followed up for 3 months, during which a beneficial effect was observed. Participants were aware that, to sustain yoga in the long term, persistence beyond this period (3 months) could not be assessed and warrants future longitudinal evaluation. A longer follow-up with inflammatory markers, such as hs-CRP, IL-6, and TNF-α, is required to assess the sustainability of the observed improvements. Future studies with larger, multicenter designs, inclusion of advanced COPD stages, and more extended follow-up of COPD patients after yoga therapy activity and re-assessment of the measured parameters, including through spirometry re-evaluation, to determine the sustenance or worsening of the condition, and to know if this improvement is only a transient phenomenon or the duration of sustenance are being followed for lung function parameters. This study is still ongoing in these patients to improve long-term outcomes.

Conclusion

This study revealed that a structured 3-month yoga intervention significantly improves pulmonary function parameters, including FEV1, FVC, FEV1/FVC ratio, SVC, and MVV, as well as BMI in individuals with stable COPD. These findings support the therapeutic potential of yoga as an effective, low-cost, and nonpharmacological adjunct to conventional COPD management, particularly in the early stages of the disease. The observed improvements may be attributed to enhanced respiratory muscle strength, improved ventilatory mechanics, better autonomic regulation, and reduced systemic inflammation. Given these benefits, incorporating yoga into pulmonary rehabilitation programs may enhance respiratory outcomes and overall quality of life in patients with COPD.

Ethical statement

The study was approved by the institutional Ethics Committee of RUHS College of Medical Sciences, Jaipur, Rajasthan, letter no. RUHS-CMS/Ethics/Comm./2023/281 dated 31/01/2024.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.