Do the arithmetic on that night

Take an eleven hour night for the sake of round numbers, which is roughly what it would have been.

Half of it asleep is about five and a half hours. A third of it in prayer is a little under four. A sixth asleep again is nearly two. Add the two sleeps together and you get around seven and a half hours of sleep, in two blocks, with the standing placed between them.

Now compare that with what usually gets recommended. Go to bed at midnight, get up at three, do not go back to sleep, and be at work at eight. That is not the schedule in the report. It is not even close to it, and nobody can run it for long.

The most beloved night prayer in the tradition sits inside an adequate night. That is the finding, and it is sitting in a sound report that hardly anybody quotes.

One classical figure sits alongside that arithmetic. Ibn Qudamah again, in Mukhtasar Minhaj al-Qasidin.

واعلم: أن الليل والنهار أربع وعشرون ساعة، فالاعتدال أن ينام من ذلك الثلث، وهو ثمان ساعات، فمن نام أقل من ذلك لم يأمن اضطراب بدنه، ومن نام أكثر من ذلك كثر كسله

Our rendering: know that night and day are twenty four hours, and moderation is to sleep a third of that, which is eight hours; whoever sleeps less than that is not safe from disturbance of his body, and whoever sleeps more than that, his sluggishness increases.

Eight hours, called moderation, in a Hanbali handbook. Two honest notes go with it. The passage carries on past where we stopped quoting, and its last clause tells a person who fell short at night to make up what he missed during the day. This course's advice differs from that clause, on clinical grounds rather than religious ones: making a short night up in the day is the compensation lesson two asks you to stop, because it takes the sleep pressure out of the following evening. And a figure from a mediaeval handbook is not a prescription for you. It is here to answer the idea that a full night is an indulgence taken at the religion's expense.