At midnight I rise to praise you, or, as our ancestors would have prayed it, Media nocte surgebam ad confitendum tibi - Psalm 119 : 62.
The ancient custom (which Carthusians still observe) of rising in the middle of the night to recite (or chant) the office of Matins or Vigils (the ancestor of our current comparatively brief Office of Readings) may not have been as physically challenging as I always assumed it to be. A recent post on Slumberwise "Your Ancestors Didn't Seep Like You" http://slumberwise.com/science/your-ancestors-didnt-sleep-like-you/ paints a picture of pre-modern sleeping patterns in which rising for the Night Office would have been just one of many options for people who were accustomed to sleeping in two shifts. Instead of our contemporary ideal of 7-8 hours of continuous uninterrupted sleep, their sleep would have been spread out over two shifts during an approximately 12 hour period - a few hours of sleep, then a couple of hours of wakefulness, then another final few hours of sleep. It made sense, of course, especially in winter when the nights were long and dark, for people to go to bed early. I always understood that, but always wondered how ordinary people (not monks and canons, who had the Office to recite) managed to sleep the whole night straight through. The answer apparently is that they didn't.
Furthermore, unlike for us moderns for whom interrupted sleep is a burden, it seems that in that pre-electric age waking up in the middle of the night was normal not problematic. As the author suggests: "The middle hours of the night, between two sleeps, was characterized by unusual calmness, likened to meditation. This was not the middle-of-the-night toss-and-turn that many of us experienced. The individuals did not stress about falling back asleep, but used the time to relax."
I'm generally sleeping better than I used to. I still sometimes wake up during the night but more often than not manage to get back to sleep. I still worry I am not getting a sufficient amount of continuous uninterrupted sleep, but what this tells me is that maybe I really shouldn't be so worried.
My only regret remains that most of my middle of the night waking time still tends to be wasted. For every time I get up and read, for example, there are many other occasions when i just toss and turn until I fall back to sleep. If only I used that time, as generations of Religious before me did, to pray the Office!