More than 30 years ago, Robert Fulghum wrote a book entitled All I Really Need to Know I Learned in Kindergarten. I’m not sure if this is in the book or not, but one thing that you learned in kindergarten remains useful throughout your life. Taking a nap in kindergarten, not sure if they even do that anymore, was not an option; and what we didn’t realize at the time is that the nap would help us recharge to get through the rest of the day.To this day, although it’s no longer mandated, I take a 20-minute nap during lunch before returning to my office for the afternoon. According to the National Sleep Foundation, a nap of 20 to 30 minutes can help improve mood, alertness and performance. More than 85 percent of mammalian species are polyphasic sleepers, meaning that they sleep for short periods throughout the day. Humans are part of the other 15 percent of monophasic sleepers, meaning that we divide our days into two distinct periods, one for sleep and one for being awake.Sleep scientists, such as the University of California, Riverside’s Sara Mednick — author of Take a Nap! Change your Life — says that naps at different durations result in different benefits. For example, a 10 to 20 minute nap will provide a quick boost of alertness while mitigating the onset of sleeplessness. At the same time, she’s not a huge fan of the 30 minute nap, saying that recovery often takes too long.Naps can be broken down into four types:• Planned napping: Also known as preemptive napping, it involves taking a nap before you get sleepy. It’s a good thing to do if you know you’re going to have a late night.• Emergency napping: This is exactly as it sounds — taking a nap when you’re so sleepy that you can’t properly engage in your current activity. This is the kind of nap that’s advisable to take when you get sleepy behind the wheel or while operating dangerous machinery.• Habitual napping: This is the practice of taking a nap at the same time every day (Such as for 20 minutes right after you eat lunch).• Appetitive napping: The act of napping strictly for enjoyment.Regular, short naps can help lower tension, which decreases your risk of heart disease. Get the most health benefits out of your nap by doing it right. Stick to a regular napping schedule during optimal hours, which are between 1 and 3 p.m. This timeframe is optimal, because that’s usually after lunchtime, when your blood sugar and energy starts to dip. Keep it short; and nap in a dark room so that you’ll fall asleep faster. Make sure to set your alarm, as well, so that you don’t nap for two long and feel groggy. You want that mid-day siesta to be beneficial..