The term sleep debt came into popular use a few years ago, but you still may not have a clear idea of what it means.
The difference between the numbers of hours you should sleep each night-about 7 or 8-and the number of hours you actually do sleep equals your sleep debt.
If you find yourself unexpectedly heading off to sleep at odd times during the day, chances are you have sleep debt.
Of course, sleep requirements are individual; not everybody "needs" 8 hours of sleep a night.
Some people are perfectly content to sleep just 7 hours a night and yet they show no signs of deprivation.
You're the best judge of how much sleep you need.
So if 7 hours of sleep leave you cranky and sleepy the next day, you obviously require more sleep and you owe your brain that extra hour of sleep nightly to stay healthy.
Also, your sleep debt is cumulative! In other words, if you miss 2 hours of sleep per night, 14 hours of sleep per week, and you do this for 4 weeks, your sleep debt would be 56 hours.
That's why college students do nothing but sleep their first week at home after final exams.
They're paying off their sleep debt and making up for the all-nighters they pulled when they were studying When you start accumulating significant sleep debt numbers every week, you're chronically sleep deprived, which means your job performance will suffer, you'll be at higher risk for either a traffic accident or on-the-job injury, and you may feel like you're shrouded in fog.
Make your health one of your most important priorities.
The National Sleep Foundation reports that Americans are getting about 20% less sleep now than they did 100 years ago.
The study cites the twin temptations of TV and internet as the prime culprits, leading 43% of adults to admit that they stay up later than they should.
On the other side of the equation, Americans are getting up earlier than before, primarily for work reasons-31% adults report that they get up at 5 a.
m.
in order to make it to work on time.
If you think that believing your brain could really be keeping track of and missing all those hours of sleep is silly, consider this fact: according to the Committee on Quality of Health Care in America, adults who get less than 5 hours of sleep over a 24-hour period experience a decline in their peak mental abilities.
So what does sleep deprivation really mean? In practical terms, try asking all the affected people (and living organisms that survived) about sleep deprivation that ultimately caused the US' worst ecological disaster.
The 3rd mate at the helm of Exxon Valdez was sleep deprived when the ship ran aground in Alaska, spilling oil and killing thousands of animals.
Additionally, a sleep-deprived engineering crew that knew the "O" rings needed replacing on the Space Shuttle Challenger in part caused the worst space program setback.
Sleep deprivation also played a role at the Three Mile Island meltdown, the Bhopal disaster, the grounding of numerous oil tanker and countless railroad collisions (asleep at the switch).
Finally according to early published reports, the pilot may have been asleep at the helm during a recent Staten Island Ferry disaster that killed 11 in New York City.