How doing yoga at 3AM can be a dream cure for insomnia: TV's Doctor Michael Mosley reveals how he defeated his sleeping problem

There is evidence that biphasic sleep, or two short sleeps a night instead of one, used to be common. 


This has been investigated by Roger Ekirch, a professor at Virginia Tech in the U.S. By exploring diaries, novels and medical textbooks, he discovered that in pre-industrial times this was how most people slept. After sunset, they would go to bed, sleep for four or five hours, then get up. This was known as 'the first sleep'.They would then stay awake for an hour or so before going back to bed for a 'second sleep'.