The evidence-based medicine perspective

Evidence-based medicine is an approach to medical practice in which decisions about the use of any intervention are based on the available evidence regarding its effectiveness and safety.

From an evidence-based medicine (EBM) perspective, research on pranayama is still at the stage of building a high-quality evidence base.

Evidence-based medicine officially recognizes scientific evidence supporting the effectiveness of pranayama techniques as a complementary method for reducing stress, normalizing heart rate, and improving lung function.

Clinical guidelines recommend pranayama as a component of lifestyle modification and rehabilitation.

However, for people with medical conditions, pranayama should not replace standard medical treatment.

1. Effects of pranayama on the cardiovascular system
   • Slow breathing techniques demonstrate a lower blood pressure within a few minutes of starting the practice 3.
   • Regular practice increases heart rate variability (HRV) and enhances vagal nerve tone. This reduces sympathetic nervous system activity and protects the heart against arrhythmias 8.
2. Pranayama and respiratory health
   • Pranayama significantly improves key spirometric parameters: vital capacity of lungs, forced expiratory volume in one second and peak expiratory flow 4.
   • Breathing exercises reduce the severity of breathlessness and the frequency of medication use in patients with chronic obstructive pulmonary disease and asthma 2.
3. Pranayama and mental health

   "When prana (breath) moves, chitta (the mind) moves. When prana becomes still, chitta also becomes still."

   Patanjali's Yoga Sutras.

   This ancient observation is now supported by neuroscientific research:

   • Reduced anxiety and stress with regular slow breathing practice 79.
   • Reduced stress markers and improved sleep quality in people with insomnia 11.
4. Improved concentration

   The Yoga Sutras state that through the practice of pranayama, "the veil covering the light is removed, and the mind becomes fit for concentration."

   Physiologically, this is explained by the balancing of oxygen and carbon dioxide, which optimizes the functioning of the visual cortex and attention:

   • significant improvements in memory and concentration after practice 14;
   • improved overall brain activity and mindfulness 6.
5. Metabolic and immune effects
   • Reduced levels of inflammatory markers, including C-reactive protein, in the blood 12.
   • Improved metabolism 10.

Limitations and controversial issues

Despite the growing number of publications reporting the health benefits of pranayama, the scientific community points to several serious methodological problems.

1. Low methodological quality

   Many studies are classified as having a high risk of systematic bias.

   Experiments often involve only 15—30 participants, which is insufficient to generalize the findings to the entire population.

2. Lack of an active control

   Critics compare pranayama with "doing nothing."

   Double blinding is not feasible: participants always know that they are breathing in a particular way, which may amplify the placebo effect.

3. Insufficient standardisation

   For scientific purposes, "pranayama" is too broad a term. For example, kapalabhati may differ in intensity and frequency from one school to another.

   Some studies last two weeks, while others last six months. This makes it difficult to conduct a robust meta-analysis and establish an appropriate "dose" of breathing exercises.

4. Short-termeffects

   Most studies assess effects immediately after a session. There is little evidence on whether these changes persist six months or a year after regular practice has stopped.

5. "Dedicated researcher" effect

   Many studies are conducted by specialized yoga institutes. There are concerns about publication bias: studies with negative results may simply go unpublished.

Common errors in interpreting research findings

When reviewing research on pranayama, knowing how to read a scientific paper is not enough; it is also important to interpret its findings correctly.

The most common mistakes when reading scientific papers include:

1. Hasty generalizations and reliance on unverified sources
   • Extrapolating from the specific to the general: if a study involved 15 young, completely healthy athletes whose endurance performance improved after practicing bhastrika, this does not mean that the technique will produce the same effect in an older person with hypertension. Extending the results obtained in a narrow population to the entire population is the most common mistake made by beginners.
   • Ignoring the credibility of the journal: articles published in journals without rigorous peer review often contain serious mathematical errors and manipulated results. Researchers should rely only on databases indexed in reputable systems.
   • Trusting "appealing" headlines: conclusions presented in the media or on popular-science blogs often sound like: "Scientists have proved that pranayama cures depression." However, the original study may show only a slight reduction in participants' scores on a subjective anxiety questionnaire, while depression itself was not clinically diagnosed.
   • Mistaking correlation for causation: if a group of pranayama practitioners feels better, this improvement cannot necessarily be attributed solely to breathing exercises. These individuals may also sleep better, follow a healthier diet, or avoid harmful habits. A high-quality study should isolate these factors through rigorous controls, but this is far from always the case.
2. Ignoring contraindications and individual characteristics
   • The illusion that yoga is completely safe: medical articles often describe the therapeutic effects of breath-holding or hyperventilation techniques, but the "Limitations" section invariably lists strict contraindications to pranayama. Ignoring these paragraphs may lead people to practice intense techniques despite existing contraindications.
   • Blindly copying rigorous protocols: if patients with asthma performed pranayama in a particular way under the supervision of sensors and medical professionals during clinical trials, this does not mean that a beginner should immediately start practicing with the same volume and intensity at home. Failure to take individual characteristics into account may result in adverse effects.
   • Ignoring the body's signals: if a study reports that a particular technique reduces heart rate, but it produces the opposite response in a specific individual, the person's own physiological reaction and consultation with a physician should always take priority.

What should you pay attention to?

1. Who conducted the experiment.

   Reputable researchers have digital citation metrics. This information can be found using the open GoogleScholar search engine by entering the author's name in the search bar, or through the official ScopusPreview portal in the author search section.

2. Which journal published the article

   The impact factor is an indicator of a scientific journal's credibility. The higher impact factors, the more rigorous peer-review standards.

   This information can be found on the journal's official website, usually in the "Metrics" section, or through the international scientific-ranking database SCImago Journal Rank.

3. Was th estudy preregistered?

   Before beginning an experiment, reputable researchers often preregister its protocol on specialised platforms such as ClinicalTrials.gov.This is done to prevent the authors from concealing unfavorable results at the end of the experiment.

For further study of pranayama, the following resources may be consulted:

• the video series Yoga for Beginners: Pranayama;
• text materials available on the Pranayama.study website;
• The online course Immersion in Pranayama.