The Short Answer Educational content only, not medical advice. Almost none of these practices has been tested directly in concussion populations, and the mechanisms described are largely inferred from healthy volunteers or other conditions. Breath-holding, forced hyperventilation, and cold exposure carry real risks and are not appropriate for everyone, particularly with cardiovascular disease, epilepsy, pregnancy, or a history of fainting. Never practice breath-holding in or near water. Stop any technique provoking dizziness, headache, or visual symptoms, and work with a concussion-experienced clinician rather than self-directing autonomic rehabilitation. Coherent breathing at roughly 5 to 6 breaths per minute produces the largest increase in heart rate variability available from any voluntary breathing pattern, because it aligns the breathing rhythm with the natural oscillation of the blood pressure control system. At that rate, heart rate rises and falls in phase with the breath and the oscillations amplify each other, a state called cardiorespiratory coherence. Heart rate variability is reduced after traumatic brain injury across a substantial body of research (Talbert et al., 2024), which makes increasing it a rational target. The fixed rate makes coherent breathing accessible with nothing more than a timer. 5 to 6 breaths per minute maximizes heart rate variability in most adults. Heart rate variability is reduced after brain injury across many studies. No equipment is needed, which is its main practical advantage. The Mechanism Behind the Rate The body's blood pressure regulation system, driven by the baroreflex, oscillates naturally at about 0.1 Hz, meaning one cycle every 10 seconds. Breathing at 6 breaths per minute matches that frequency exactly. When the two rhythms align, the heart rate oscillation driven by breathing and the oscillation driven by blood pressure regulation reinforce each other, and the amplitude of heart rate variation increases substantially (Lehrer & Gevirtz, 2014). This is a resonance phenomenon in the mechanical sense. It explains why 6 breaths per minute is not an arbitrary wellness number and why faster or much slower rates produce smaller effects. Why Heart Rate Variability Matters After Concussion Reduced heart rate variability after traumatic brain injury is one of the more consistent findings in the literature, documented across severity levels and time points in systematic and scoping reviews (Talbert et al., 2024, and Pinto et al., 2024). It reflects disrupted autonomic regulation, and it corresponds clinically to the exercise intolerance, heart rate spikes, orthostatic symptoms, and poor stress tolerance many people describe. Whether raising heart rate variability through training improves outcomes, rather than simply moving a measurement, is the harder question, and the randomized trial of heart rate variability biofeedback in mild traumatic brain injury provides the most direct support (Lu et al., 2023). How to Practice It The pattern is deliberately simple: inhale for 5 seconds, exhale for 5 seconds, continuously, with no holds. That gives 6 breaths per minute. A 5.5-second version gives about 5.5 breaths per minute and suits many people slightly better. Breathe through the nose with relaxed, moderate volume rather than deep breaths, since large breaths at a slow rate cause hypocapnia and lightheadedness. The abdomen should move before the upper chest. Use a timer, a pacing app, or a visual guide, since counting occupies attention that is better spent relaxing. Ten minutes daily is a reasonable target dose. The Common Errors That Undermine It Two mistakes account for most failures. The first is breathing too deeply, which people do naturally when told to breathe slowly. Large tidal volumes at 6 breaths per minute blow off CO2 and produce dizziness and tingling, which people then attribute to the technique itself. The correction is smaller, quieter breaths. The second is straining to hold the rate, which raises arousal and cancels the autonomic benefit. If 5 seconds each way is uncomfortable, start at 4 and extend gradually. Comfort is the requirement rather than a nice extra. Coherent Breathing Versus Individualized Training Coherent breathing uses a fixed rate for everyone. Resonance frequency training measures each person's optimal rate, which usually falls between 4.5 and 6.5 breaths per minute and is stable within an individual (Lehrer & Gevirtz, 2014). The individualized version produces larger effects, and it requires equipment and a trained clinician. Coherent breathing captures most of the benefit for most people at no cost, which makes it the sensible starting point. Where autonomic symptoms are prominent and persistent, moving to properly assessed resonance frequency training with a clinician is the logical escalation. Breathing work handles the autonomic side of recovery. Joint mobility handles the mechanical side, and rib cage and neck restriction limit how well any breathing technique works. Start your 3-day free trial to combine both in a 2-3 minute daily routine. Supporting Mobility Routine JME 155 Diaphragmatic breathing is the base position for every technique below. Practice it separately until the pattern holds without effort. Ten slow breaths, several times daily. JME 150 Thoracic rotation restores the mid-back motion a full diaphragmatic breath depends on. Restricted thoracic spines force upper chest breathing. Eight repetitions per direction. JME 227 Overhead reach opens the rib cage and thoracic spine, raising the mechanical ceiling on slow deep breathing. Ten repetitions with controlled tempo. JME 14 Chin tucks reduce upper cervical tension, which lowers the accessory breathing muscle load at the neck. Ten repetitions with 5-second holds. JME 1 Cervical rotation restores segmental mobility and supports blood flow through the vertebral arteries. Ten repetitions per direction. JME 15 Cervical lateral flexion releases scalene tension, a common driver of upper chest breathing after neck injury. Ten repetitions per side. JME 16 Cervical flexion and extension restore sagittal mobility restricted by suboccipital guarding. Eight slow repetitions. JME 2 Cervical retraction reinforces a neutral head position, which mechanically favors diaphragmatic over apical breathing. Ten repetitions per set. Start your 3-day free trial for joint-specific mobility programming supporting the rib cage and neck mechanics behind good breathing. Common Mistakes Breathing deeply rather than at normal relaxed volume Straining to maintain 5 seconds when 4 is the comfortable limit Counting mentally instead of using a pacer Practicing occasionally for long sessions rather than daily for ten minutes Adding breath-holds, which breaks the continuous rhythm the effect depends on Chasing a heart rate variability number from a consumer wearable Assuming a raised measurement guarantees symptom improvement Progression Start at whatever equal in-out count is comfortable, often 4 seconds, for 5 minutes daily using a pacer. Extend toward 5 seconds each way as it becomes effortless, and build to 10 minutes daily. Keep breaths small and quiet throughout, correcting any lightheadedness by reducing volume rather than rate. After four to six weeks, judge by symptoms and daily function rather than by any device reading. Where autonomic symptoms remain prominent, ask a clinician about assessed resonance frequency training. What rate should coherent breathing use? Five to six breaths per minute, most simply achieved with a 5-second inhale and 5-second exhale and no holds. That rate matches the roughly 0.1 Hz oscillation of the baroreflex, which is why heart rate variability increases most at that frequency. Why does slow breathing make me dizzy? Almost always because the breaths are too large. Deep breaths at a slow rate lower CO2 and cause lightheadedness and tingling. Keep the volume normal and quiet, letting the rate rather than the depth do the work, and the dizziness resolves. Does raising heart rate variability improve concussion symptoms? The most direct evidence is a randomized controlled trial of heart rate variability biofeedback in mild traumatic brain injury reporting symptom improvement. Reduced variability after brain injury is well documented, though moving the measurement is not automatically the same as improving outcomes. Is a wearable heart rate variability score useful for this? Only loosely. Consumer readings vary with sleep, alcohol, illness, position, and measurement conditions, so daily fluctuation swamps training effects. Use symptoms, exercise tolerance, and daily function as the measures rather than chasing a device number. How is coherent breathing different from resonance frequency breathing? Coherent breathing applies a fixed rate near 6 breaths per minute to everyone. Resonance frequency training measures each person's individual optimum, typically between 4.5 and 6.5 breaths per minute, which produces larger effects but requires equipment and clinical assessment. What the Evidence Actually Supports Three claims are well supported. Slow breathing at roughly 6 breaths per minute produces measurable autonomic and central nervous system changes in healthy people, including increased heart rate variability and reduced subjective arousal (Zaccaro et al., 2018). Heart rate variability is disrupted after traumatic brain injury, with reduced variability documented across multiple studies and populations (Talbert et al., 2024, and Pinto et al., 2024). And heart rate variability biofeedback, which trains breathing at an individually determined resonance frequency, improved symptoms in a randomized controlled trial in mild traumatic brain injury (Lu et al., 2023). That trial is the strongest direct evidence linking a breathing intervention to concussion outcomes. Beyond those three, the evidence thins quickly. Most named breathing protocols have never been compared against each other, almost none has been tested in concussion, and the vagal stimulation practices circulating widely online rest on mechanistic plausibility rather than outcome data. Principles for Breathing Practice After Concussion Slow the rate before lengthening any single phase, since rate does most of the work Make exhales longer than inhales, the one consistent finding across techniques Breathe through the nose unless congestion prevents it Keep sessions short and frequent rather than long and occasional Stop immediately if dizziness, headache, or visual symptoms appear Avoid breath-holding and forced deep breathing in early recovery Treat comfort as the limit, since strain defeats the autonomic purpose Practices With Weak or Absent Concussion Evidence Several widely promoted practices deserve honest labeling. Gargling, humming, and cold face immersion are recommended as vagus nerve stimulation on anatomical grounds, meaning the structures involved share vagal innervation, but no trial demonstrates they improve concussion symptoms. Bilateral stimulation has been studied mainly as a component of eye movement desensitization therapy rather than as an autonomic intervention, and its independent physiological effect remains unclear. Polyvagal theory, which underpins much of the popular framing around vagal tone, has faced substantial scientific challenge to its core premises (Grossman, 2023). None of this makes these practices harmful, and several are pleasant, free, and low-risk. It does mean they belong in the category of reasonable things to try rather than treatments with demonstrated benefit. When to Involve a Clinician Autonomic symptoms after concussion, dizziness on standing, exercise intolerance, heart rate spikes, and breathlessness, warrant assessment rather than self-management, because they overlap with conditions needing specific treatment such as orthostatic intolerance, vestibular dysfunction, and cervical injury (Silverberg et al., 2020). A clinician also identifies whether a genuine dysfunctional breathing pattern exists, which changes the approach considerably. Heart rate variability biofeedback in particular works best with proper assessment, since the resonance frequency is individual and training at the wrong rate loses most of the benefit (Lehrer & Gevirtz, 2014). Symptoms persisting beyond the expected recovery window need reassessment rather than more self-directed practice. References Zaccaro, A., Piarulli, A., Laurino, M., et al. (2018). How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 12, 353. PubMed Lehrer, P. M., & Gevirtz, R. (2014). Heart rate variability biofeedback: how and why does it work? Frontiers in Psychology, 5, 756. PubMed Lu, H. C., Gevirtz, R., Yang, C. C., et al. (2023). Heart rate variability biofeedback for mild traumatic brain injury: a randomized-controlled study. Applied Psychophysiology and Biofeedback, 48(4), 405-421. PubMed Balban, M. Y., Neri, E., Kogon, M. M., et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1), 100895. PubMed Talbert, L. D., Kaelberer, Z., Gleave, E., et al. (2024). A systematic review of the relationship between traumatic brain injury and disruptions in heart rate variability. Applied Psychophysiology and Biofeedback, 49(4), 523-540. PubMed Pinto, S. M., Wright, B., Annaswamy, S., et al. (2024). Heart rate variability after traumatic brain injury: a scoping review. Brain Injury, 38(8), 585-606. PubMed Thorne, J., Hellewell, S., Cowen, G., et al. (2023). Neuroimaging to enhance understanding of cardiovascular autonomic changes associated with mild traumatic brain injury: a scoping review. Brain Injury, 37(10), 1187-1204. PubMed Conder, R. L., & Conder, A. A. (2014). Heart rate variability interventions for concussion and rehabilitation. Frontiers in Psychology, 5, 890. PubMed Santino, T. A., Chaves, G. S., Freitas, D. A., et al. (2020). Breathing exercises for adults with asthma. Cochrane Database of Systematic Reviews, 3(3), CD001277. PubMed Weitzberg, E., & Lundberg, J. O. (2002). Humming greatly increases nasal nitric oxide. American Journal of Respiratory and Critical Care Medicine, 166(2), 144-145. PubMed Vickhoff, B., Malmgren, H., Aström, R., et al. (2013). Music structure determines heart rate variability of singers. Frontiers in Psychology, 4, 334. PubMed Grossman, P. (2023). Fundamental challenges and likely refutations of the five basic premises of the polyvagal theory. Biological Psychology, 180, 108589. PubMed Silverberg, N. D., Iaccarino, M. A., Panenka, W. J., et al. (2020). Management of concussion and mild traumatic brain injury: a synthesis of practice guidelines. Archives of Physical Medicine and Rehabilitation, 101(2), 382-393. PubMed