Many people today seem to see sleep as less important than other activities (such as work), but that’s a mistake. “Every human needs it…. It’s a requirement for life,” said Michael Grandner, PhD, of the Penn Center for Sleep and Circadian Neurobiology, adding wryly, “That alone should send us a message that maybe it’s important.”
Indeed, from tiny fruit flies all the way up the evolutionary ladder to humans, animals need this time to rebuild, repair, and replenish. Quoting Allan Rechtschaffen, a pioneer in sleep research, Grandner said, “If sleep doesn’t serve some vital function, it is the biggest mistake evolution ever made.”
But why is sleep so important? Many of the major restorative functions in the body – like muscle growth and tissue repair – occur at night. Genes that are sensitive to sleep loss control the production and transport of proteins that perform many functions, such as basic maintenance on the cellular level. And, while a computer’s “brain” may wind down during the sleep mode, the human brain does not.
In fact, the brain remains quite busy the entire night, processing the countless pieces of information an average person takes in during the day, to make sure everything is properly consolidated and integrated into long-term memory. “The brain is basically restocking shelves, sorting through the experiences of the day before and getting you ready for the next day,” Grandner said. “This information becomes part of who you are – your personality, your beliefs, your experiences.”
Not getting enough sleep for the brain to finish its task every night could lead to problems. “You can become more stressed, less able to handle what life throws at you,” Grandner said. “You’re not on your game, physically, mentally or emotionally.”
But what is “enough” sleep? Grandner and David Dinges, PhD, chief of Sleep and Chronobiology, were part of a committee of sleep experts who evaluated the current literature and found that seven hours of sleep per night promotes optimal health in healthy adults. While this does not mean every person requires this amount, the group reported that sleeping less than seven hours per night has been associated with health problems. But sleeping too much may not be good either, Grandner said. Over the course of a lifetime, “an average person who sleeps less than seven hours a night -- or more than nine hours -- has a shorter lifespan.”
So now that you know how good sleeping is for you, how can you help yourself get enough sleep? Stay active… with “purposeful” physical activity. A recent Penn study, led by Grandner, showed that while cleaning and childcare may require effort, they won’t get you the healthy sleep you need. “Not only does this study show that those who get exercise simply by walking are more likely to have better sleep habits, but these effects are even stronger for more purposeful activities, such as running and yoga, and even gardening and golf.”
Finally, if you’re one of those people who ends each day using a mobile device, you might want to change your bedtime routine. “Using your device at night,” they noted, “especially if it’s interrupting your sleep unexpectedly, can leave you stressed and may ultimately lead to sleep problems.”