For years, napping has been derided as a sign of laziness. We are "caught" napping or "found asleep at the switch". But lately it has garnered new respect, thanks to scientific evidence that midday dozing benefits both mental acuity and overall health. A slew of recent studies have shown that naps boost alertness, creativity, mood, and productivity in the later hours of the day.
A nap of 60 minutes improves alertness for up to 10 hours. Research on pilots shows that a 26-minute "Nasa" nap in flight (while the plane is manned by a copilot) enhanced performance by 34% and overall alertness by 54%. One Harvard study published last year showed that a 45-minute nap improves learning and memory. Napping reduces stress and lowers the risk of heart attack and stroke, diabetes, and excessive weight gain.
Getting even the briefest nap is better than nothing. A 2008 study in Düsseldorf showed that the onset of sleep may trigger active memory processes that remain effective even if sleep is limited to only a few minutes. And last year, a British study suggested that just knowing a nap was coming was enough to lower blood pressure.
Naps make you brainier, healthier, safer. But to understand how you can nap best, you need to understand your body.
• Jennifer Ackerman is the author of Sex Sleep Eat Drink Dream: A Day in the Life of Your Body