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's Church in Rome, built in 1960 for the needs of the Olympic Village, continues as a modern, well-visited parish church. Saint Valentine is commemorated in the Anglican Communion, as well as in Lutheranism. February 14 The Lutheran Service Book, with its penchant for the old Roman calendar, commemorates Valentine on this date. By some of the Eastern Orthodox Church, Saint Valentine the Presbyter of Rome is celebrated on July 6 and Hieromartyr Valentine (Bishop of Interamna, Terni in Italy) is celebrated on July 30.