You Don’t Know Jack About Sleep
We all know that exercise is good and junk food is bad, but what about sleep? That’s right – being a lazy bed bum might be what you need to get in shape. Sadly, not many know exactly how sleep works.
People brag about strange things: like working 80 hours a week or cramming the night before a big exam. How much time they spend in the gym is another one, or how wrecked their body is after “leg day.”
A big badge of honor would be missing out on sleep. I hear people brag about functioning on four hours of sleep as if it’s a good thing. Did you know that going 24 hours without sleep gives you the cognitive abilities of having a .1 blood alcohol level?
Bedtime just isn’t a priority and often takes a backseat to browsing your phone, watching TV or hanging out with friends. But if you’re serious about building a healthy body, you might not need as many miles on the treadmill as you thought. Prepare to fluff those pillows and get under the covers.
The biggest issue is that people really don’t understand what happens when we sleep. It was the late researcher Dr. William C. Dement, in his book The Promise of Sleep, who talked about his difficulty in getting grant money to study the health benefits of sleep. No one wanted to give him money because, well, they didn’t think it was all that important.
But it is. And as time has passed becoming an unhealthy society means turning over more rocks to battle obesity. We now have access to more research that’s shown just how much of in impact poor sleep hygiene has on our bodies.
Your sleep is broken down into 5 stages. Stages 1 and 2 are relatively light – that’s the sleep where your inconsiderate roommate can easily wake you up as they raid the fridge for a late night snack. Stages 3 and 4 are deep sleep in which you’re less likely to wake from slight noise. These are the stages were the body releases hormones responsible for growth and repair.
Lastly, there’s REM sleep, which refers to rapid eye movement. This is where dreaming occurs. It takes about 90 minutes to go through each stage. A good night’s sleep means you might go through each phase 5 times. But if you’re one of these people that fall asleep and constantly wake up throughout the night, your body is suffering. Staying up late means you’re only going through the phases 3 times.
Those repair hormones I mentioned are highest around midnight. These hormones include growth hormone and thyroid stimulating hormone (which is a step in the process of your body releasing thyroid hormones). If these hormones don’t get balanced out, then you run of the risk of elevating cortisol (yet another hormone in the body). High levels of cortisol means your body may store fat and weaken your immune system. In fact, chronically high levels of cortisol have been known to shrink your lymphatic organs. The lymphatic system helps build white blood cells and detoxify the body.
Your optic nerve sits right next to a part of your brain called the suprachiasmatic nucleus. The nucleus regulates your sleep wake/cycle while the optic nerve helps adjust to light – so you can see how the two work together. Staying up late with a 70 inch TV blasting at the foot of your bed isn’t the best idea. Your best bet for good sleep is to treat your bedroom like a cave and try to cool it with toying around on your phone.
So just how bad for your body is a lack of sleep? A meta-analysis showed that those who slept less than six hours a night over a four year period had higher levels of obesity compared to those who slept more (1). In fact, researches are even able to show the exact weight gain from sleep deprivation. Short sleep, defined as 5 hours or less, can lead to a .35 increase in BMI (2). If you don’t want to do the conversions, I’ll do it for you: that means a three pound weight gain for someone who is 5’10.”
Here you can scoop up some good sleep habits.
When it comes to getting in shape, sleep falls into the “boring but basic” category (much like everything else that works). The occasional late night isn’t going to do much damage, but if you’re super serious about getting fit, practicing good sleep hygiene is a must.
1. Mozaffarian, D. Hao, T., et al. “Changes in Diet and Lifestyle and Long Term Weight Gain in W-omen and Men.” (2011) New England Journal of Medicine 364.25, 2392-2404
2. Cappuccio, F.P., et al. “Meta-Analysis of Short Sleep Duration and Obesity in Children and Adults.” (2008) SLEEP 31;5. 619-626