Train yourself in spiritual readings:
Religious readings are numerous and limitless. However, sacred fasting days, should not be used to read books that increase your knowledge as much as the ones of worship. Concentrate on spiritual books that inflame your heart with God's love, stimulate you, leading you to prayer, and urge you to repent and lead a life of purity. Such should be your reading material to stimulate you in a spiritual way. As for other religious books, I do not forbid you to use them. However, they come second in a fast, while spiritual books and biographies of saints take priority.