Breath retention, or apnea, is the structured practice of consciously pausing the breath, with deep roots in ancient traditions like yogic pranayama. Known as kumbhaka in yoga, this technique has been used for centuries in meditation and is now being investigated by modern science for its effects on the body and mind. The practice involves a deliberate cessation of breathing for a controlled period, forming the basis of various structured breathing routines.
Physiological Response to Holding Your Breath
When you hold your breath, oxygen (O2) levels in your blood decrease while carbon dioxide (CO2) levels rise. This buildup of CO2 is the primary driver of the urge to breathe again, not the depletion of oxygen. As CO2 accumulates, it triggers chemoreceptors in your brain and major arteries, sending strong signals to the respiratory center to resume breathing.
This process engages the autonomic nervous system, which regulates involuntary functions. The rising CO2 and the act of holding the breath can stimulate the vagus nerve, a part of the parasympathetic nervous system. This stimulation helps shift the body from a sympathetic “fight-or-flight” state to a more relaxed “rest-and-digest” state, an effect that is pronounced during holds after an exhalation.
The practice introduces a state of intermittent hypoxia, a brief, controlled period of reduced oxygen supply that triggers adaptive responses. According to the Bohr effect, the increased CO2 concentration during a hold causes oxygen to be released more readily from hemoglobin to the body’s tissues. This can paradoxically increase tissue oxygenation, even as blood oxygen levels temporarily dip.
Common Breath Retention Techniques
Box Breathing, or Sama Vritti Pranayama, is a simple and calming method. To practice it, you inhale for a count of four, hold your breath for a count of four, exhale for a count of four, and then hold with empty lungs for a final count of four. This cycle creates a “box” of four equal parts and is repeated for several minutes to promote balance and calm.
Another common approach is retention after inhalation, or Antara Kumbhaka, featured in methods like the Wim Hof Method. It begins with a series of deep breaths to fully oxygenate the body. After the final inhalation, the breath is held in a relaxed manner, without force, until the urge to breathe becomes strong.
A more advanced technique is retention after exhalation, or Bahya Kumbhaka. This involves exhaling completely and then holding the breath out for a period. This form of retention is more challenging due to the strong and immediate urge to inhale it produces. It is used in yogic traditions to cultivate internal awareness.
Potential Mental and Physical Applications
The physiological shifts from breath retention have several applications. The stimulation of the vagus nerve helps reduce stress and anxiety by activating the parasympathetic nervous system. This can lower heart rate, reduce blood pressure, and promote a feeling of calm that counteracts the body’s stress response.
Disciplined practice can improve focus and mental clarity. Holding the breath demands concentration, training the mind to remain steady under physical discomfort. Over time, building a higher CO2 tolerance can lead to a less reactive nervous system, improving composure and concentration.
Breath retention may also enhance physical performance and resilience. Intermittent hypoxia can trigger the body to improve oxygen efficiency and produce more red blood cells, which could benefit athletic endurance. Training the body’s response to a breath hold may also build resilience to other stressors, such as cold exposure.
Safety and Considerations
While breath retention offers benefits, it is not suitable for everyone and requires caution. Individuals with certain medical conditions should avoid the practice or first consult a healthcare professional, as changes in blood pressure and oxygen can pose risks. These conditions include:
- Pregnancy
- High blood pressure
- Cardiovascular diseases, such as arrhythmias or a history of heart attack
- Neurological conditions, like epilepsy or a history of seizures
Distinguish between the normal discomfort of the urge to breathe and genuine warning signs. If you experience certain symptoms, stop the practice immediately, as pushing beyond these limits can lead to loss of consciousness. Warning signs include:
- Dizziness
- Lightheadedness
- Sharp pains
- Feeling close to fainting
Practicing in a safe environment is necessary. Never practice breath-holding in or near water, including a bathtub or swimming pool, due to the risk of drowning from a phenomenon known as shallow water blackout. Always practice in a seated or lying position to prevent injury in case you faint.