Anuloma Viloma TimerMost studies of breathwork measure what happens over weeks. The participants practise daily for a month or two, the researchers take a measurement at the start and a measurement at the end, and the paper reports the difference.
A 2025 study published in September and indexed on PubMed did something different. It measured lung function before and after a single pranayama session, with a clinical-grade spirometer. The result is one of those numbers that sits on the page and asks the reader to look twice.
Forced vital capacity rose significantly. Forced expiratory volume in one second rose significantly. Peak expiratory flow rate rose significantly. All three of these are measurements that physicians use to assess respiratory function. They are not subjective. They are what a pulmonologist would read off the machine if a patient walked into a clinic.
And the participants had practised for 60 minutes. One session.
What the study did
The trial enrolled 20 healthy adults. Each participant was measured on a spirometer before the session and again immediately after. The intervention was a single 60-minute pranayama practice. The outcomes were the three standard pulmonary function measurements: FVC, FEV1, and PEFR.
FVC, forced vital capacity, is the total volume of air a person can exhale forcefully after a maximum inhale. It is a measurement of lung volume.
FEV1, forced expiratory volume in one second, is how much air a person can push out in the first second of that exhale. It is a measurement of how easily the airways move air.
PEFR, peak expiratory flow rate, is the maximum speed of that exhale. It is a measurement of muscular and airway capacity together.
All three are different ways of asking the same family of questions. How much air can you move, how fast, and how cleanly. Together they describe the mechanical state of the respiratory system.
The participants’ numbers were higher after one session of pranayama than before it. The improvements were statistically significant. This is not a “feels better” outcome. This is a calibrated instrument reporting a different reading from the same person, less than two hours apart.
The meta-level support
A single-session study with 20 participants is provocative. It is not, on its own, a body of evidence. Fortunately the body of evidence exists.
A 2026 systematic review and meta-analysis published in PMC pooled 10 randomised controlled trials covering 1,007 patients with various respiratory and clinical conditions. The intervention across the trials was yoga, with pranayama as a primary component. The outcomes were the same pulmonary function measurements. The result: a weighted mean difference of 3.03 litres in FVC percent improvement, and statistically significant improvements in FEV1.
A 3.03-litre weighted mean difference in FVC is not a sensational number to a person reading wellness content. To a pulmonologist it is a substantial signal across a clinical population. The meta-analysis pulled together 10 separate trials and found that yoga and pranayama produce meaningful, measurable improvements in lung function, in patients, over sustained practice.
Pair the two papers and you get a coherent argument. One pranayama session produces immediate, measurable changes in pulmonary function. Sustained practice produces clinically meaningful improvements over time. The short story and the long story tell the same direction.
Why this is unusual in the wellness literature
Most claims about breathing and the body operate at the level of metaphor. Breathwork “opens the chest.” It “expands the lungs.” It “improves breathing.” Those phrases mean something, but they do not survive contact with a spirometer.
The September 2025 study made the claim measurable. The number on the spirometer printout is the same kind of number a doctor uses to assess asthma management, to track the progression of chronic obstructive pulmonary disease, to clear an athlete for return to training after a respiratory illness. When a pranayama session changes that number, it has moved out of the metaphor category and into the physiology category.
This is the direction the broader research base has been moving. The 2025 systematic review of alternate nostril breathing in the International Journal of Research in Medical Sciences (44 RCTs) reported consistent improvements across autonomic, cardiopulmonary, and cognitive measures. The 2026 UC San Diego review of 660 vagus nerve studies confirmed slow nasal breathing as one of the strongest non-invasive activators of the same neural pathway that surgical implants target. The lung-function literature is one more measurement axis in the same picture.
Why the technique matters, not just the breathing
A subtle but important point in the pulmonary literature is that not every breathing practice produces the same effect. A 2026 randomised controlled trial registered at the Istanbul Medipol University Hospital is currently comparing fast pranayama and slow pranayama directly, on the assumption (well grounded in earlier research) that the two patterns affect the respiratory and cardiovascular systems differently. Fast pranayama, sometimes called Bhastrika, hyperventilates briefly and mobilises the system. Slow pranayama, of which Anuloma Viloma is the most studied example, downregulates the autonomic baseline and trains respiratory muscle endurance.
For lung function specifically, slow pranayama is the pattern that the literature points at most consistently. The long inhale strengthens the diaphragm. The retention after the inhale (antara kumbhaka) holds the chest expanded for a moment, which the literature suggests improves alveolar recruitment, particularly in the lower lobes that are often underused in shallow chest breathing. The long exhale tones the expiratory muscles. The retention after the exhale (bahya kumbhaka) trains tolerance to carbon dioxide, which has its own neural effects.
Anuloma Viloma packages all four of those phases into a single, repeating cycle. That is not a coincidence. The technique was designed, by lineages that did not have spirometers, to do exactly the thing the spirometers are now measuring.
The practical version
If a person reads the September 2025 study and wants to try the protocol the participants used, the entry point is small. The 60-minute session length used in the trial is at the upper end of what most home practitioners will tolerate. The same physiology, scaled to a sustainable daily protocol, looks like this.
Sit upright. Five minutes is enough for the first week. Close the right nostril with the right thumb. Inhale slowly through the left for a count of four. Close the left with the right ring finger and hold for two. Release the right nostril, exhale through it for four. Hold empty for two. Inhale through the right for four. Hold for two. Close the right, exhale through the left for four. Hold empty for two. That is one round.
The count is the engine. The exhale count matches the inhale count at first. Many traditional curricula gradually extend the exhale (four-two-eight-four is a common intermediate ratio) once the practitioner has settled in. The retention counts grow last, and only under guidance for longer ratios. The four-two-four-two starting ratio is well within what an untrained adult can do safely.
The 60-minute trial length collapses to five minutes for a daily practice and still produces meaningful effects over weeks, based on the broader RCT literature. A practitioner is not chasing the single-session number from the lab. They are building the underlying respiratory capacity that the single-session number was sampling.
Why a timer specifically
The 60-minute pranayama session that the September 2025 trial used was almost certainly delivered by a teacher in a clinical research setting. A home practitioner does not have a teacher counting beside them. The two practical alternatives are a guided audio app or a structured timer.
A guided audio session prescribes the pace. The voice cues the inhale, the hold, the exhale, the hold. That works well for a beginner during the first few sessions. After that it tends to compete for attention with the practice itself.
A timer does the opposite. The four phases are named on screen, the ratio holds steady, and the practitioner counts internally. The Apple Watch haptics let a person run the full protocol without looking at the phone. The same five-minute session can be repeated identically day after day, which is exactly what the protocol-replication side of the research literature recommends.
The Anuloma Viloma Timer was built for this. The full Nadi Shodhana protocol is on the free tier. The four phases are named, the ratio is held, and the practice runs in silence unless the practitioner asks for haptic cues. There is a subscription tier for richer customisation but the technique the September 2025 study used does not require it.
What this does not say
A few caveats worth keeping in view.
The September 2025 study had 20 participants and measured an immediate post-session effect in healthy adults. It is a real result, but it is not, on its own, a license to claim that a single session of pranayama “cures” anything. It is a license to claim that one session of structured slow breathing produces a measurable change in pulmonary function in healthy adults. Which is what the paper says.
The 2026 PMC meta-analysis covered 10 RCTs with 1,007 patients, which is a much larger evidence base, and it pointed in the same direction across clinical populations. A patient with asthma, COPD, or any other respiratory condition should still discuss any breathing practice with their doctor before changing their regimen.
Pranayama is not a substitute for inhalers, oxygen therapy, pulmonary rehabilitation, or any other medically supervised intervention. It is, increasingly, a tool that the same medical literature is recommending alongside those interventions.
That recommendation is what the recent research is starting to put on paper. The number on the spirometer changes after one session. The number gets better with sustained practice. The technique has been around for two thousand years and is now being measured by the kind of instruments that hospitals trust.
Anuloma Viloma Timer is free on the App Store. No subscription necessary.