So an article was just published in the January 2011 edition of Oprah regarding the benefits of adequate amounts of "dark" sleep. I had to chuckle a little at this because it seems that once things hit Oprah, they tend to take off (at least for a while). As a health and fitness professional, I find it worrisome that this "news" (which is not new - plenty of research has shown over the last few decades just how beneficial sleep is) goes through mainstream media in cycles, but never really settles in as practice. This blog is intended to educate on the importance of adequate amounts of sleep, and how light itself is involved.
People just don't realize that adequate sleep is a huge player in weight control and general health. Like most other processes in life, sleep has a profound effect on our hormones, which essentially are the driving forces behind our metabolism. If you follow the logic presented here as "paleo" living, it makes sense to also realize that our physiological system is finely tuned (or should be) to the day/night cycle of the earth. Over hundreds of thousands of years without the use of artificial light, we evolved something called a "circadian rhythm". This is simply a cycle that dictates how certain hormones are released throughout the day/night cycle. In a normal cycle, cortisol (the stress hormone) is elevated in the morning hours to prepare an individual for the day ahead, and is supposed to diminish in the winding hours of the evening. Light is a powerful stimulant of cortisol (blue light being the worst - TV, computer) through contact with the sensors of the eyes. So, if we stay up too late watching TV or blogging on the computer, we will have disrupted the normal cortisol rhythms. Also, it is the absence of light that stimulates another hormone, melatonin (not to be confused with melanin which gives us skin pigmentation), which is our most powerful antioxidant and is vitally important to a strong immune system. We need lots of extra sleep when we are sick because our body knows we need to produce extra melatonin to fight the infection. So a lack of sleep and prolonged exposure to light will promote a longer cortisol rhythm (bad) while suppressing the production of melatonin (bad). Studies show that even a little bit of light exposure (even that coming in through the window or under the door) has an inhibitory effect on melatonin production.
The best time to get good sound sleep is the first few hours (preferably starting at least by 10 pm). During this first 2-3 hours of deep sleep, growth hormone is at its peak, helping with muscle/bone/connective tissue repair (and we all know what growth hormone in the system does for fat metabolism!). During this same time, melatonin is also at its peak. The caveat here is that it takes a while for cortisol to clear the system. So, if you spend your evening right before bed winding down with "stressors" (TV, computer, sugary snacks, late night exercise, fights with your spouse, etc), your repair/immune hormones will again be inhibited and wasted. The great thing about the benefits of sleep, are that it is really not that difficult to change your pattern. Below are some simple tips for a long, dark, and healthy night's sleep.
1) So easy a cave man could do it (but didn't have to) - KEEP IT DARK! Put up some heavy shades, block the door with a towel, and cover or turn off all LED lights from computers, DVD players, alarm clocks, etc.
2) Wind down from the day around 8 pm with low lighting (get romantic and use candles), and read a book instead of watching late evening television
3) Try and keep a regular sleep schedule so your rhythms don't get confused
4) Avoid stimulants after lunch (coffee, high glycemic foods, nicotine)
5) Find a healthy way to mentally relax and wind down if prone to high stress
6) Don't drink too much water before bed so you won't have to use bathroom late at night (if you do, hang a flashlight from your doorknob- the shock of turning a bright light on in the bathroom will certainly trigger your cortisol and quickly inhibit your melatonin and growth hormone)
7) Along with that, drink plenty of water throughout the day to stay hydrated (the body sees dehydration as a stressor)
8) Shoot for at LEAST 8 hours (nothing wrong with 10!)
