Early Christian Lent Fasting Practices

What information do we have about early Lent fasting practices? I saw an interesting reference to Ramadan having grown out of Syrian Lent practices, but aside from that, I haven't found any good descriptions of early Christian fasting methods outside of 7th century Syria. Generally when I read about early Christian fasting I just assume they were abstaining from food and drink for the entire period referenced but they obviously couldn't do that for 40 days and 40 nights. If the practices are poorly documented during the early church, at what point does something resembling a standardized Catholic 40 day/night fast begin to emerge?