Exhalation Strategies

An open-mouth exhale reduces airflow resistance, while a pursed-lip or smaller-mouth exhale increases airflow resistance. The main difference between the two exhalation strategies is mouth position rather than force. For wide presentations, a smaller-mouth exhale creates more airflow resistance and can help recruit the external obliques. For a narrow presentation, an open-mouth exhale lowers airflow resistance and reduces the likelihood of over-recruiting the abdominals. Both exhalation strategies should be prolonged and slow-paced. Excessive resistance or fast forceful exhalation can cause rectus abdominis dominance and disrupt desired pressure mechanics. A narrow infrasternal angle generally calls for a strategy that helps open the angle. A wide infrasternal angle generally calls for a strategy that helps close the angle.