By Shelby Freedman Harris, Psy.D. for YouBeauty.com

We know about the benefits of a good night’s sleep -- better memory, attention, concentration and a reduced risk of heart attack and stroke. Sleep improves our mood; it makes us feel like we can do more in the day and gives us a better outlook on life. But in addition to helping us live productive lives, sleep is key to feeling and looking youthful. Here are five surefire ways.

1. You Look More Attractive To Others
In a 2010 study published in the British Medical Journal, a group of Swedish investigators looked at whether sleep-deprived people were perceived as less healthy, less attractive and more tired than after a normal night’s sleep. Twenty-three healthy adults were photographed after a normal night’s sleep (about eight hours) and again after a night of sleep deprivation (31 hours of wakefulness!). The photos were presented to 65 untrained observers who rated them. Results indicated that sleep-deprived people appear less healthy, less attractive and more tired when compared to photographs taken after a full night's sleep.

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The authors proposed that humans may be sensitive to sleep-related facial cues, and that these cues may affect your social life in big ways. For example, if someone is well-qualified for a job but hadn’t slept well for a few nights, employers might perceive the candidate as being less healthy and more tired -- putting the candidate at risk of not getting hired.

What exactly is going on during those precious sleep-filled hours at night that’s keeping us looking and feeling young? A lot.

2. You Stay Fitter
As we wrote in Sleep More and Fit Into Your Skinny Jeans, sleep helps you manage your weight. Consistently getting less sleep than you actually need per night leads to slow and steady weight gain. This weight gain can impact how others view you (unhealthy, tired) and how you may view yourself (tired, unmotivated). If you sleep more, you’ll find it easier to lose weight and will even have more energy to exercise. It is also commonly accepted now that exercise helps us feel younger both physically and mentally.

3. Your Skin Glows
Skin grows a lot in our sleep. We develop nearly 30 times more skin while asleep than when awake. Notice those dark circles and bags under your eyes after a poor night’s sleep? The skin of a healthy sleeper is more elastic, supple and taut. The more you get a full night’s sleep, the more you’ll have that youthful glow.

4. You're Quicker To Move, And Learn
Our mind and bodies learn new things while we sleep. Studying the night before a big test and then getting a full night’s sleep can solidify the material in your brain. Pulling an all-nighter without sleep can actually make it more difficult to learn new material. But more than just brain cells learn and grow throughout the night! Our muscles, ligaments and tissues all learn new routines to help us physically maneuver throughout the world --whether it is to help with balance, new dance moves or picking up a new sport.

5. You Boost Your "Youth" Hormones
Finally, human growth hormone (HGH) has its highest production during slow-wave sleep. HGH is a key player in keeping us looking young even after we’ve finished growing. HGH is produced by the pituitary gland and is in high levels during childhood and adolescence. After we’ve grown, HGH levels drop off and stay at low, steady levels during adulthood. Deficiencies in HGH can lead to reduced muscle mass, slower metabolism, more belly fat and sagging skin. Sleep more, and you’ll likely increase your HGH levels.

Even getting one or two fewer hours of sleep per night on a consistent basis can have long-term damaging effects for our bodies and mind. Regularly placing sleep at the bottom of your “to-do” list can make it harder for you to look and feel your best. If you don’t make sleep a priority, then you’re not making yourself a priority. And if you don’t take care of yourself, you’ll have more trouble taking care of everyone else around you and crossing off all the other “to-dos” on your list.

Make sleep a priority and you’ll look and feel a whole lot younger.

For more on sleep, click here.

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