No matter how good the schedule is, nothing replaces sleeping when your body clock actually wants you to sleep.

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Basically we have a tiny little gland in the middle of our brains that controls when we sleep and when we are awake as well as many other things. And many of us are programmed, as it were, to either be night owls (want to go to sleep late) or larks, where we want to go to bed early.

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For example, people with heart failure develop a breathing pattern where they stop breathing (at different times) throughout the entire night. That actually wakes them up repetitively and so people with heart failure will have trouble falling asleep and they'll wake up sometimes very short of breath.

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This problem often begins in people when they're in their mid-teens.

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