By Dr. Mehmet Oz, MD and Dr. Michael Roizen, MD

President John Kennedy did it. Winston Churchill and Lyndon Johnson planned it for a specific time daily. We’re talkin’ about The Nap.

 We’ve long advocated the benefits of the 10-minute nap (less stress, more energy and focus), but now the National Sleep Foundation says a 20 to 30 minute nap will do even more to improve your mental and physical alertness without interfering with nighttime sleep. (Naps of 60 minutes per day or longer are not so good for you; they’re associated with a 50 percent increased risk for type 2 diabetes.)

One study (with a distracted control group) even claims a short daytime nap could improve your short-term memory five-fold. A better-structured, earlier study found that after three months, nappers retained much more of what they learned than their control group, and that group wasn’t distracted.

The point is, done correctly an afternoon siesta (the word comes from the Roman word for sixth hour, sexta, or our noon) is much better for your health than gulping down an energy shot. Find a place to rest for 10, 20 or 30 minutes a day (whatever suits you best), use eyeshades to block out light and recharge. Doing it at the same time every day helps stabilize your circadian rhythms.

Power-napper Salvador Dali would close his eyes with a key in hand. When he was so asleep that the key hit the ground, he would get up and start painting again, often portraying time as clocks draped over tree branches.