Since we were children, we’ve all heard the advice that we should get eight hours of sleep each night. With 24 hours in a day, that amounts to a third of the day and, ultimately, a third of our lives.
Unfortunately, most of us are missing the mark.
The National Sleep Foundation recommends 7-9 hours of sleep per night. However, it says that around 40 percent of us get less than 7 hours. Moreover, a survey by Gallup finds that Americans currently average 6.8 hours of sleep at night, down more than an hour from 1942.
Life has gotten faster and more hectic at the expense of our sleep and, ultimately, our health.
Scientists are still discovering the myriad of reasons we need sleep and just how valuable it is. For example, in studies on rats deprived of sleep for just five days, the end result was death. Sleep was found to be as essential as food because the rats died just about as quickly from sleep deprivation as from food deprivation.
For athletes and exercise enthusiasts, sleep is vital to athletic performance, as well as muscle growth and recovery.
Protein synthesis occurs when we sleep, provided that protein is ingested prior to sleep. This is why it’s useful to eat some protein, or drink a protein shake, before bed.
Sleep is also the time when our bodies produce growth hormone. In men, 60% to 70% of daily growth hormone secretion occurs during the early stages of sleep, which is typically when the deepest sleep cycles occur. Consequently, poor quality sleep can negatively effect human growth hormone levels.
Additionally, the total amount of growth hormone secreted by men in their 30s and 40s deceases significantly, meaning that sleep becomes even more vital as we age.
Yet, sleep is vital at every age. Research shows that sleep deprivation in otherwise healthy young men can result in decreased testosterone levels and increased spikes of cortisol, a stress hormone.
Furthermore, lean muscle is regenerated in the final couple of hours of sleep each night. During REM (late-stage) sleep, the body undergoes several critical processes, including: restoring organs, bones and other tissues; replenishing immune cells; and circulating human growth hormone. For these reasons, sleep has a significant effect on muscle growth and recovery.
Research shows that being sleep-deprived can actually encourage loss of muscle mass and hinder muscle recovery after a tough workout. Ultimately, sleep is vital in order for the body to grow and repair muscle.
Then there’s the issue of weight management.
Research shows that people who don’t sleep for 7-8 hours a night are more prone to weight gain.
When you’re sleep deprived, leptin (the hormone that signals satiety) falls, while ghrelin (which signals hunger) rises. This combination leads to an increase in appetite. Additionally, sleep deprivation tends to lead to food cravings, particularly for sweet and starchy foods.
Researchers have suggested that these sugar cravings stem from the fact that your brain is fueled by glucose (blood sugar). Therefore, when you lack sleep your brain is unable to properly respond to insulin (which drives glucose into brain cells), so it becomes desperate for carbohydrates to keep going. If you’re chronically sleep deprived, consistently giving in to these sugar cravings will virtually guarantee that you’ll gain weight.
Getting too little sleep also dramatically decreases the sensitivity of your insulin receptors, which will raise your insulin levels. This, too, is a surefire way to gain weight, as the insulin will seriously impair your body’s ability to burn and digest fat. Getting proper sleep is therefore crucial for maintaining a healthy weight.
Several large-scale studies from all over the world have reported a link between short sleep times and obesity, as well as heart disease, high blood pressure and stroke. This indicates that we are not biologically designed for sleep deprivation. In fact, other than humans, there is no other mammal that deprives itself of sleep. This deprivation puts great stress on the mind and body.
Sleep deprived subjects are found to be hungrier, less alert and, most importantly, unable to metabolize sugar effectively, putting them at increased risk for Type 2 diabetes. In one study, in which sleep was restricted to four hours per night for six nights, the subjects ended up in a pre-diabetic state. Consequently, in addition to aging, overweight/obesity and family history, sleep deprivation may be a new risk factor for diabetes.
Research indicates that, aside from proper diet and exercise, sleep must now be viewed as essential to good health. Ultimately, lack of sleep impacts our appetite, our metabolism, our memory and even how we age.
The good news is that napping can help too. Brand new research is showing that long naps, including REM sleep, can even improve emotional outlook, making people less sensitive to negative experiences and more receptive to positive ones.
So, make sure you get about eight hours of restful sleep each night, and don’t worry about sleeping a third of your life away.
Go on, get some sleep.