Sleep
What’s Enough?
If you feel sleepy during the day, whether in a “boring” lecture or in front of the TV, you probably need more sleep. Without enough sleep, your attention span is shortened and you can become increasingly irritable.
Sleep needs are highly individual.We all have an internal clock that sets bodily functions, including when we are most alert and when we sleep best during a 24-hour period (our circadian rhythm).
Some students:
- Need as little as 7 hours of sleep; others need 10 (most need 8 to 10)
- Can sleep through anything; others are awakened easily by sound, light, or temperature change
- Are most alert in the evening; others in the morning (this characteristic is genetically determined)
Is Sleep a Waste of Time?
No. Your brain never rests, even when you’re asleep. It remains electrically andmetabolically active, tending to its nighttime tasks as you snooze away.
Recordings of electrical impulses from the brain show two distinct kinds of sleep: REM (Rapid Eye Movement) or “dream sleep,” and NREM (Non-Rapid Eye Movement).
Each type of sleep performs a different (but vital) function. NREM sleep helps you to attend and concentrate during the day. REM sleep consolidates short-term memory (such as the new concepts, facts, and skills you learn in a day) into longterm memory, enabling you to retain it.
Sleepiness
Here are causes and cures for most daytime sleepiness:
Sleep Debt: Do you deprive yourself of sleep, then later crash? If so,you’ve created a “sleep debt,” and lost much of the benefits of the REM and NREM sleep that you’ve missed.
As long as you don’t get an adequateamount of sleep, the debt grows larger.
When this debt is large enough, it can take at least two weeks of getting the rightamount every night to catch up.
Naps can help pay off sleep debt. Even a 10 or 20 minute nap can make a difference. If you wake up from a short nap feeling crummy,don’t worry. In an hour or so you’llhave renewed energy.
Note: if you have difficulty sleeping atnight,don’t nap.
Phase Delay: You can override your natural tendency of being a morning or an evening person by establishing a different sleepwake cycle. Switching over to another pattern creates a “phase delay” which can cause daytime sleepiness, even if you are getting enough total hours of sleep.To correct this, reset your internal clock by going to sleep and getting up at roughly the same time every day.Do this consistently,and be sure to include weekends.
Jet Lag: When you fly across time zones, your circadian rhythm is out of synch withthe day-night cycle of your new environment. It’s best to try to switch over to yournew location’s schedule immediately.
Sleep Disorders: If you sleep 8 to 9 hours a night and are still sleepy during the day, you could have a sleep disorder, especially if you snore loudly while asleep. There can be serious health consequences, so discussthe situation with a medical practitioner.
Trouble Sleeping?
- Avoid caffeine, nicotine, and heavy use of alcohol
- Sleep in a comfortable and quiet place (earplugs can help)