What is RSA breathing?

Respiratory sinus arrhythmia (RSA) way of breathing creates the right ratio of oxygen in the pre-frontal cortex in a way that we can measure doing HEG training and that can help the brain adjust to the requirements of the cognitive tasks we need to do.

When an area in the brain is more active, it needs more Oxygen and nutrients, hence, more blood supply (this is called the BOLD response). So, more haemoglobin needs to carry more oxygen molecules to that area in the brain. This can work the other way too – you can teach your brain to increase oxygen levels at the front of the brain and as such to support attention and focus for longer.

Frontal activation of the brain using Oxygen Patterns training has been shown to help improve symptoms of inattentiveness and ADD related symptoms. Click here to read more about HEG training research.

There is a way to teach yourself to breath in a way that supports oxygen patterns training. This is called RSA breathing.

How do I practice RSA breathing?

RSA breathing practice is based on three principles:

1. Focus on exhaling only. No active inhaling

2. Abdomen breathing vs chest breathing

3. Nasal inhale vs mouth breathing

The idea is that you do not take an active breath in at any point. Breath normally (in through your nose), and when you notice that you started exhaling, exhale slowly through your mouth to the count of 7. Put your hand on your belly and feel your belly going in as you exhale, squeezing out the air from your lungs, like a toothpaste out of the tube – from your abdomen and up. When all the air is out, give it another tiny squeeze and then just let your belly muscle go.

You know when you do it right because:

1. Your lungs will suck back in the exact amount of oxygen they need, without you actively inhaling.

2. You will not feel dizzy at any point. If you do, it means you actively inhaled and took too much air (and oxygen in)

3. Your chest will not be going up and down with the breathing exercise. Rather, it will be your belly doing it.

Why is it good for the brain?

RSA is used in research to document changes in anxiety, stress and health, all of which have been shown to have a relationship with lowered heart rate variability (respectively, anxiety (Chalmers, 2014); stress (Kim, 2018); and poor health (Lampert, 2008)).


RSA measures decrease when a person is stressed or has to be more attentive to their emotional state (Porges, 2007).

• As such, greater RSA amplitude represents better cognitive control of emotions necessary for appropriate processing of negative affect (Thayer & Lane, 2000).

• On the contrary, reduced RSA at rest can indicate maladaptive cognitive reflection to emotional conditions as low RSA reflects poor homeostatic response of the autonomic nervous system, which in turn causes less resilience to stressors (Park, 2014, Gross, 201).

RSA was also suggested to correlate with, and affect cognitive functions (Morgan, 2007).

• Better performance in cognitive tasks that specifically require attention and working memory functions has been shown in participants that demonstrated higher RSA (Hansen, 2003).


Respiratory sinus arrhythmia (RSA) is a component of the measure of heart rate variability (HRV). It is a measure of autonomic regulation as it measures heart rate variability (the length of heartbeat intervals) when it is in synchrony with respiration (Malik, 1995). Autonomic regulation is mediated by the parasympathetic system, specifically by the nervous vagus (Berntson, 1997). RSA is an indication to the cardiac vagal control of the heart since its degree is affected directly by inspiration (when heart rate accelerates) and expiration (when heart rate decelerates). As such, higher vagal tone means a synchrony between HRV and respiration, causing RSA measures to increase (Berntson, 1997).