Sleep is the cheapest performance booster there is, and the first thing most busy people sacrifice.
What sleep does for your brain
- Memory. During sleep the brain replays and stores what you learned, moving it from fragile to lasting.
- Attention. After a short night, focus lapses and reaction time slow.
- Reasoning and mood. Tired people make more errors, think less flexibly and react more strongly to stress.
- Clean-up. Researchers think sleep helps clear waste products from brain tissue.
How much do you need?
Most adults do best with seven to nine hours. Teenagers need more. A few people really do fine on less, but far fewer than claim to.
Habits for better sleep
- Keep fixed wake-up and bedtimes, even at weekends.
- Get daylight in the morning.
- Stop caffeine in the early afternoon.
- Dim lights and screens an hour before bed.
- Keep the bedroom cool, dark and quiet.
- Do not go to bed hungry or stuffed, and go easy on alcohol: it makes sleep lighter.
Before any big test
Do not stay up revising. A rested brain on the day beats an extra hour of last-minute practice. If you plan to take an IQ test, sleep well the night before and test in the part of the day when you feel sharpest.
If you often struggle to sleep or wake unrefreshed, ask a doctor: treatable conditions such as sleep apnea are common.
When you are rested, take the Real IQ Test and see the difference.