Lack of sleep leads to a condition called “sleep debt”, which is the cumulative effect of not getting enough sleep, whether it is partial (less than 8 hours a night) or total (amount of sleep over weeks). Sleep does not work like your phone plan’s rollover minutes. The benefits of sleep occur from consistently getting a good night’s rest. You can’t get 6 hours one night and 10 hours the next to equal an average of 8 hours because you have created a sleep debt that could take weeks to repay.
The following are some of important facts that we know about sleep debt:
- Your maximum sleep debt is approximately 20 hours.
- You can’t “sleep ahead” and build up a sleep reserve.
- You can’t pay back more than 2 hours of sleep debt at a time.
- Losing one hour of sleep per night for a week is equal to staying up all night!
Calculating how much sleep you need.If you feel drowsy during the day, you probably didn’t get enough sleep the night before. Try going to bed earlier and see if you feel alert the next day. If you do, this is your nightly sleep need. If you don’t go to bed 30 minutes earlier and see if this works.
Paying back sleep debt. You can’t replace lost sleep all at once. If you lose two nights of sleep you won’t sleep for 14-16 additional hours on the third night. When you sleep longer to catch up, go to bed earlier than usual. Otherwise your normal waking time will be shifted. This is likely to make it difficult to get to sleep at the usual time the following night. You can also take a nap to help you pay back your sleep debt. But make sure that you nap in the early afternoon. Taking a nap in the late-afternoon will shift your biological clock, making it harder to get up in the morning.
Why not just sleep in on weekends to pay back sleep debt? You can’t make up for large sleep losses during the week by sleeping in on weekends any more than you can make up for lack of regular exercise and overeating during the week by working out and dieting only on the weekends.Dr. Charles Czeisler, director of the division of sleep medicine at Harvard Medical School and consultant to several professional teams, warns that lost sleep over days can’t be made up by one long sleep. According to Dr. Czeisler, a person who goes a week with four hours of sleep per night has an impairment equal to a blood-alcohol level of 1%.
Gene Coleman, Ed. D., RSCC-E, FACSM, was the Head S&C Coach for the Houston Astros from 1978-2012 and is currently a strength and conditioning consultant for the Texas Rangers and Professor in the Exercise and Health Sciences Program at the University of Houston – Clear Lake.