Why 6 Hours of Sleep Isn’t Enough

You can’t shed pounds overnight, but solid slumber can help you maintain your healthy weight overtime. While past studies have indicated that sleep deprived people tend to consume more calories from junk food, a new study suggests these cravings are instigated in the brain, not the belly. Researchers at the University of California, Berkeley, found that when sleepy subjects were shown images of fatty foods, it triggered a strong response in the area of their brains associated with appetite, as well as a decrease in activity in the area related to making rational decisions based on consequences. Meaning if you’re burning the midnight oil, not only will you likely crave more high-calorie foods, you’ll be less likely to resist them. Even more eye opening was that the study found that the urge to snack had nothing to do with the body’s need for energy to make up for a lack of sleep. Even when energy needs were met, participants still craved high-carb, high-fat foods.

But if the science doesn’t convince you, consider the most obvious weight-gain dangers associated with lack of sleep: the more hours you spend awake, the more calories you’re going consume, as you’re likely to require more meals in 20 hours than you are in 16. And there’s no question that if you’re dragging your tired butt around, your workouts are going to suffer, so those extra calories get stored as fat rather than burned as fuel.

You may not realize it, but the strong, toned physique you’re after doesn’t get built in the gym. Muscle growth and repair occurs during the deep stages of sleep, when hormones required for restoration and development are released. You’ve heard of human growth hormone? It’s most abundant while you’re in dreamland.

But if that’s not enough incentive to start getting more sleep, consider these serious sleep stats: Fatigue can cause negative side effects on a metabolic level too, impairing your endurance performance as well as recovery, not to mention increasing your risk of type 2 diabetes.

Research from the University of Chicago Medical School studied the effects of three different durations of sleep in healthy, young males. After only one week of reduced sleep (four hours per night), the participants’ ability to manage glucose levels in their blood slowed by almost 40 percent. This influence on the body’s ability to process glucose is supported by several studies that suggest a correlation between sleeping less than five hours a night and an increased risk of type 2 diabetes.

During the sleep deprivation period, the subjects also experienced elevated levels of the stress hormone cortisol, a catabolic hormone linked to impaired recovery in athletes, as well as memory impairment, age-related insulin resistance and the accumulation of abdominal fat.

At the very least, you can’t give it your all in the gym if you’re exhausted—you may even end up hurting yourself if you’re feeling weak or unfocused. Making an effort to hit the hay a little earlier not only allows your body to properly recover from your last workout, but restores your energy so you can make the next one count too.

According to the National Sleep Foundation, there is no magic number that applies to everyone. Some people require more time with the pillow to feel as refreshed and rested as others. What can be said with certainty is that research shows individuals who regularly clock seven to nine hours of quality sleep tend to enjoy healthier and longer lives.

As for how many hours you need for optimal health and athletic performance, the answer is as individual as you are. First, consider your lifestyle habits, how you feel throughout the day and how well you slept the night before. Statistically speaking, you likely are not one of those rare individuals who really can do well with only five hours of sleep. Start aiming for seven to eight hours, and use your alarm clock as a clue. “If you are getting enough sleep you will naturally wake up at the same time each day, likely about five minutes before the alarm,” says Richard Bonato, PhD, and registered sleep technologist.

If you’re getting approximately eight hours of ZZZ’s each night consistently and still can’t live without the alarm clock, you could be suffering from a sleep disorder and should check in with your doc or consider visiting a sleep clinic.