Surprisingly the answer to your question is quite involved. I will answer it from a freedivers point of view. First of all, holding your breath has different effects depending on what circumstances you do it under. When you exercise normally your breath will increase as a response to the increased levels of CO2 in your blood.
February 14 is celebrated as St. Valentine's Day in various Christian denominations; it has, for example, the rank of 'commemoration' in the calendar of saints in the Anglican Communion. In addition, the feast day of Saint Valentine is also given in the calendar of saints of the Lutheran Church.
Saint Valentine, officially Saint Valentine of Rome, is a widely recognized 3rd-century Roman saint commemorated on February 14 and since the High Middle Ages is associated with a tradition of courtly love. All that is reliably known of the saint commemorated on February 14 is his name and that he was martyred and buried at a cemetery on the Via Flaminia close to the Ponte Milvio to the north of Rome on that day. It is uncertain whether St. Valentine is two different Saints. Several different ma