The amount of sleep you get can make or break your tomorrow. Anyone who's ever done it — which means most people — knows that not enough sleep can damage their health. But so can too much sleep; it's associated with obesity and diabetes, according to the Wall Street Journal. The proper amount of rest leaves people happier, more physically fit and more productive, Business Insider reported.
In February 2015, the National Sleep Foundation suggested new amounts of snooze time based on scientific literature. It suggested that young adults (18 to 25 years old) and adults (26 to 64 years old) should get about seven to nine hours of shut-eye, according to the guidelines. Other studies are stern about the sweet spot being seven and not eight hours, having "lowest mortality and morbidity" rates, according to the Wall Street Journal.
A 2013 study in which people recorded their amount of sleep and then took memory and matching or arithmetic tests found the zenith of "cognitive performance" to be seven hours, the Wall Street Journal reported. More than that and the scores began to decline.
But getting just a half-hour short of seven hours can already reap negative effects on the next day, such as decreasing one's attention span.
Studies have found that the average amount of sleep time for Americans varies from 6.8 hours to 8.75 hours, according to the Washington Post. A 2013 Gallup poll found that 40% of Americans get less than seven hours of sleep. In fact, people are getting less sleep as the years go on.
People can figure out their optimal sleep duration by turning off an alarm clock, going to bed while tired and avoiding electronics, caffeine or alcohol for three to seven days, experts said, according to the Wall Street Journal. During this trial period, people should keep a sleep diary and see what nights leave them most refreshed and awake during the day.