Re: how can you increase ventilation in your body

hi Sandi,

The need to take a breath is determined by the level of carbon dioxide (CO₂) in your body. This is a very complex physiological process but basically, there are receptors in your body that detect the level of CO₂ (and the pH of your blood, which falls when CO₂ levels rise). At a certain CO₂ concentration, these receptors interact with your nervous system and "tell you" to take a breath, which washes the excess CO₂ out of your lungs.

If you take short, rapid breaths (this is called hyperventilation), you remove excess CO₂ from your lungs. This allows you to hold a breath longer, because the CO₂ level is not high enough to trigger the breath response. You can use this trick when you are snorkelling to stay under water for longer. However it can be quite dangerous - you should never do it for more than 3 or 4 rapid breaths, as you can become faint and even pass out.

This is a nice web page explaining the control of ventilation if you would like some more technical details.