Why your boss should let you nap at work? | The Economist

TL;DR

Afternoon naps of 10–30 minutes improve alertness and memory more than caffeine, and regular napping reduces heart disease risk by 37%.

Key Points

• 1.Humans are biologically wired for biphasic sleep. Neuroscientist Matthew Walker argues modernity has distorted natural sleep patterns; a 2007 study of 23,000 Greek adults found giving up afternoon siestas raised heart disease risk by 37%.
• 2.Power naps outperform caffeine for afternoon performance. Research shows a midday nap beats coffee at improving alertness and memory, and can even reverse the effects of a bad night's sleep.
• 3.The optimal nap is 26 minutes, taken between 1–3 p.m. NASA's 1994 study found a 26-minute nap improved pilot performance; napping later than 3 p.m. risks disrupting nighttime sleep.
• 4.Stay within 10–30 minutes to avoid sleep inertia. Entering deep sleep within a 90-minute cycle causes grogginess; naps over 60 minutes regularly increase risk of diabetes and cardiovascular problems.