Recitation of the Ave Maria (Hail Mary) prayer or a common yoga mantra slows breathing rate to 5.5-6 breaths per minute and improves markers of cardiovascular and autonomic health. They can be thought of as both health and religious practices.
HRVB (and, hence, slow breathing) is a powerful adjunctive therapy for managing a wide variety of chronic diseases. To be effective, it should be practiced for a minimum of 10 min/day (but probably 20+ for best results—see next section). More broadly, this study supports using slow breathing at around 5-6 breaths per minute in people with chronic diseases.