Always breathe through nose - even during exercise. The most basic of all the breathing techniques is to make sure we are always breathing through our nose.

• Mouth breathing tends to promote hyperventilation, which actually decreases tissue oxygenation.
• It can also elevate our heart rate and blood pressure, sometimes resulting in fatigue and dizziness.
• CO2 level in our body and decreases the ability to filter toxic pollutants from the air.

Breathing through the mouth may be tempting particularly during physical exertion. Most people breath through mouth while working out. We should really try to avoid this tendency. We should be exercising only to the extent that we can continue breathing through our nose the majority of the time. If this mean backing of on intensity, then thats what we need to do, as it is very important for our body to get used to "air hunger" as it will help our body to begin to adjust to slightly increased CO2 level.

The elasticity of our lungs also depends on nasal resistance, which we only get from nasal breathing due to the smaller diameter of our nasal passage. Good breathing technique such as Nasal Breathing is even associated with  good posture. So breathing through nose helps us maintain our health in a number of important ways.