Dear Dr. Jeff: I've been reading reports about adolescents not getting enough sleep. Do you think that's a big problem at Bowdoin? - A Concerned Parent
Dear C.P.: Most of us don't get enough sleep. Forty percent of Americans are so sleepy during the daytime that it interferes with their daily activities. Adolescents, notoriously, don't get enough sleep. Most experts seem to feel that adolescents, on average, need between 8.5 and 9.25 hours of sleep nightly, but are only getting about seven hours.
Annual surveys here at Bowdoin consistently show half of students reporting that they go to sleep after 1:00 a.m. on weeknights and get up by 8:00 a.m. Not surprisingly, these same students indicate that they have trouble staying awake in class at least once or twice a week, and nearly one-third of them feel too tired to function. More than 80 percent of students at Bowdoin report that they wish they could get more sleep.
Sleep is very simply a basic necessity of life, as fundamental to our health and well-being as air, food, and water. If we don't sleep well, or sleep enough, almost every aspect of our lives will suffer. When we're sleep deprived, we're less alert, less attentive, less able to concentrate, less able to make clear judgements, and less productive. We're also more irritable, more emotional, at increased risk for health and psychiatric problems, and, of course, more dangerous while operating machinery like bikes or cars. Over 100,000 car crashes each year are caused primarily by fatigue. They claim over 1,500 lives and cause over 70,000 injuries. Half of these fatigue-caused crashes involve drivers under the age of 25.
Sleep deprivation has been shown to impair memory formation and judgement. One study of first-year college students showed that sleep habits accounted for the largest amount of variance in GPA. Another study showed that people who were taught a skill and then deprived of REM sleep (the stage of the sleep cycle during which dreaming occurs), couldn't recall what they had learned. Other studies have demonstrated a distinctive and progressive impairment of one's ability to think quickly and to multi-task, as one is increasingly sleep deprived. Even a single "all-nighter" produces a measurable decline in intellectual performance, most notably between 6:00 a.m. and 11:00 a.m. the following morning.
Sleep needs are genetically determined and can't be changed. You can't "adapt" to getting less sleep than you biologically need. Although you can somewhat improve your performance of specific tasks while sleep deprived, you won't be able to achieve optimal or consistent performance levels.
Some of us need more sleep, some less. If you wake up rested and refreshed in the morning, you're probably getting enough sleep. If, on the other hand, you routinely roll over to snatch a few extra zzz's in the morning, or you need to catch up on your sleep on weekends or holidays, or you're put right to sleep by long meetings, boring lectures, overheated rooms or "heavy" meals, then you are probably not getting enough sleep.
Sleep deprivation is cumulative, and can't effectively be "made up." The more nights you get insufficient sleep, the sleepier you'll get each day.
Making up for lost sleep on weekends can be a two-edged sword. Studies have shown that irregular sleep schedules, and especially large shifts in sleeping and waking hours, can contribute to changes in sleep phase (the tendency to fall asleep and stay asleep at a given time of night). These changes can in turn lead to insomnia and fragmented, poor quality sleep.
Daytime naps certainly help. After all, more than half the world takes an afternoon siesta or xiu xi! Naps, though, need to be brief (no more than one hour), taken early in the afternoon, and should be avoided altogether if getting to sleep or staying asleep at night is difficult.
What about those who have trouble falling asleep?
A balanced diet and regular exercise are both important for high quality sleep, but not right before bedtime. Vigorous exercise can raise your internal body temperature and thereby delay sleep onset. Avoiding caffeine and other stimulants for at least four hours before bedtime, and alcohol and nicotine at least two hours, is also advisable. Alcohol may help you get to sleep, but it can fragment your sleep cycles, leaving you drowsy in the morning. For the same reasons, bedtime alcohol may also impair memory formation (not a good thing the night before an exam!).
A few other tips. Maintain as regular a bedtime and waking time as you can. Spend time outdoors, every day, out in the light. Develop bedtime routines to cue your body into sleep. Take a warm bath, or drink some herbal tea or warm milk, or listen to music or read. Find some stress-reducing activity that will help you relax?before you get into bed for that good night's sleep.
Be well! Sleep well and sleep enough!
Jeff Benson, M.D.
Dudley Coe Health Center