A couple months back, I met a successful individual that proclaimed they only sleep for four hours a day. I immediately made the assumption that their success must be due to the extra 3-4 hours in their day and their unwavering dedication to work. I now think it is the latter and not so much the lack of sleep.
Living in the Bay Area, the topic of sleep has again made it to the forefront of my thoughts. I constantly hear that “sleep is for the weak” or “nobody has time for sleep”. I find it hard to believe that the most successful people are the ones that sleep the least.
People are different, so I don’t think we should all prescribe to the same sleep schedule. On average most people sleep between 7 and 8.5 hours a day. Why is that? Why do all humans sleep? If the current life expectancy in the U.S. is 79 years and we all sleep approximately 8 hours a day, then that’s 26 years of our life that we’ve spent asleep. In other words, we sleep for 30% of our lifetime.
Anything that deserves 30% of our lifetime must play a fundamental role in our lives. I’ve read through a few studies on sleep and learned that it plays an important role in our ability to manage our body temperature, it helps with tissue recovery and is essential for memory consolidation. When we are sleep deprived, our cognitive performance goes down. We know that when our cognitive performance goes down, so does our alertness. Low cognitive performance and low alertness means that we cannot sustain effort or attention. This is one of the main mechanisms that results in accidents. Here in the United States, there are more car accidents and fatalities associated with sleep impairment than there are with alcohol.
Sleep and chronic health:
That’s crazy, but one of the things that I found even more alarming was that lack of sleep can lead to long term health consequences and chronic medical conditions. Insufficient sleep can potentially lead to type 2 diabetes by influencing the way that our bodies process glucose. Healthy people that cut back their sleep from 8 to 4 hours per night processed glucose slower than those allowed regular sleep. This is also supported by studies that show adults sleeping less than 5 hours a night have an increased risk for developing diabetes.
Sleep and the immune system:
When we are feeling sick, where do we go? Straight to bed (aside from the hospital). When our immune system is fighting an infection, it also makes us a bit tired. Studies on animals show deep sleep after a microbial infection gives them a better chance of survival.
Sleep and alcohol:
What about alcohol? Well people that have poor sleep habits tend to drink alcohol more prevalently. Alcohol is a sedative, so it is commonly abused to help with the inability to sleep. The problem is that the sedative effects of alcohol only last a few hours and as our bodies process the alcohol, it begins to stimulate arousal and can cause awakening later in the night. It’s easy to see how this can become a reinforcing cycle.
Chronic sleep deprivation:
Chronic sleep issues have been correlated with depression and anxiety. People that sleep less tend to report being more stressed, angry, sad and mentally exhausted. I know that I get frustrated quickly and don’t like to talk to people when I haven’t slept well. The silver lining is that these effects on mood improved dramatically when a normal sleep schedule was readopted.
Sleep and obesity:
I don’t want to keep beating a dead horse on why you should get proper amounts of sleep, but this last part is probably the most eye opening. Weighing in with overeating and lack of exercise, sleep is now seen as a potential risk factor for obesity. During sleep, our bodies secrete hormones that help control our appetite, metabolism, and glucose (as I mentioned earlier). Insufficient sleep can affect the balance of these hormones. One of these is our “stress hormone” called cortisol. Poor sleep leads to an increase in the production of cortisol.
Do I think that a very small proportion of people out there can function on 4 hours of sleep? Yes. There is evidence that a small number of people (approximately 1%) are biologically different and they can operate on little sleep. In general, though, I’m fairly convinced that sleep is fundamental to our health and wellbeing, and that only 4 hours is not enough. Yes, sleep is for the weak, but it’s what makes them stronger. It’s not how many hours we work, rather it’s the work we put into those hours. If you really want more hours, give up the traditional weekends. Get rest and conquer your day.