What is the perfect nap duration?

Napping can be risky. Will you wake up feeling better or worse?There's no doubt that sometimes an afternoon snooze is an absolute necessity. Norman and Tegan explore what's going on when you nap, and what you can do to get the most benefit.References:Influence of mid-afternoon nap duration and sleep parameters on memory encoding, mood, processing speed, and vigilanceLifestyle mediators of associations among siestas, obesity, and metabolic healthEffects of planned cockpit rest on crew performance and alertness in long-haul operations