Recommendation: Set your alarm clock for the latest time you absolutely must be awake. Go to bed 7-8 hours before that time. Get up when you wake up naturally. Use sunlight and/or some refreshing cold water to shake off drowsiness. Adjust according to your schedule.
You May Be In Control
One study of young people showed that when they expected to wake up at a certain time, levels of the pituitary hormone adrenocorticotropin began to rise about an hour before the scheduled wake-up time. ((Timing the end of nocturnal sleep)) ((Timing… Abstract)) This is physiological evidence to support claims made over the past 120 years by previous studies and surveys reporting ability and (at least perceived) benefit to self-wake. ((Statistics of “Unconscious Cerebration”)) ((Subjective and objective confirmation of the ability to self-awaken at a self-predetermined time without using external means)) ((Subjective… Abstract)) We also have a physiological explanation why a warm bath helps you fall asleep and cold water wakes you up–as you fall asleep, vasodilation in the extremities lowers your core temp and takes blood to the hands and feet. When you wake up the opposite occurs via vasoconstriction. ((Waking up properly: is there a role of thermoregulation in sleep inertia?”))
Why Wake Up Naturally?
Whenever you wake up, that lingering drowsiness is called “sleep inertia”. In one study, 10 undergrad and grad students in good health with no history of self-awaking performed better on reaction tests when they self-awoke. They also, of course, reported less fatigue and higher motivation. ((The effect of self-awakening from nocturnal sleep on sleep inertia)) In a study of elderly people (avg. age 74; Standard Dev= 5), subjects slept on two different occasions. During one, they woke themselves up naturally and during the other were “forced awake” by the voice of the experimenter. The study controlled for temperature, humidity, previous/recent sleep quality, health issues, etc. When “forced awake” there was a significant increase in blood pressure (both systolic and diastolic) and heart rate. None of these occurred when they woke themselves up. In fact, blood pressure was lower after napping in this case. This study supported similar findings regarding increases in heart rate in young people. ((The effects of self-awakening on heart rate activity in a short afternoon nap))
Not The Time To Discuss Inadequate Sleep
While researching this topic, I came across so… much… data about how unhealthy sleep deprivation is. It was annoyingly ubiquitous. I wanted to include some here but there’s enough to justify it’s own post. I’ll just say that I need to do a little more studying but it appears a week’s worth of 5 hour nights could almost qualify you as diabetic. But I’m not losing sleep over it, thanks to my new glucose monitor!