Quality vs. Quantity: What Sleep Do You Need Most?

Getting your z's in many ways makes you invincible since sleep is essential for your mind and body to operate at full capacity. Research has shown that too little sleep results in more accidents on the road and at home, daytime sleepiness, concentration difficulties, poor job and school performance, increased weight gain, and health issues.

The trouble is in a 24/7 culture, it's difficult to find or have the time get enough sleep. According to the National Sleep Foundation most adults require seven to nine hours of sleep each night to function well the next day. (Infants may sleep as many as 16 hours a day.) However sleep quality seems to be an important factor in determining how well rested you feel—regardless of the number of hours spent in bed. In part, this phenomenon may explain why six hours of quality sleep in some individuals is sufficient while eight or nine hours of sleep for others is not.

Hans Van Dongen, PhD, professor and sleep expert at Washington University in Spokane says that many people don't realize their sleep is inferior until someone else points it out. "It's often a matter of their partner telling them they are restless in bed or they snore all the time—behaviors that compromise sleep quality," Van Dongen explains. "They may never have linked symptoms such as being tired during the day or concentration difficulties to sleep quality problems."

Known demographic risk factors for poor sleep quality include: older age, being female, non-white, having less education and/or low income, and being unmarried. Medical and psychological risk factors include cardiac problems, the use of certain medications, physical inactivity, depression, and anxiety.

Though there is little consensus about the exact definition of poor sleep quality, it's commonly associated with ease of waking, tiredness, sense of balance and coordination, clear headedness, feeling refreshed or restored, mood regulation, and physical feelings on waking. Most experts agree that feelings of tiredness during the day predict poorer sleep quality; alertness predicts the opposite.

Van Dongen blames the culture. "We've decided to use each 24-hour period to the fullest and automatically give up sleep for wakefulness in an attempt to get more done," says the professor adding that almost no one can get the recommended seven to nine hours. "Over time insufficient sleep (due to quality or quantity) ever so slightly chips away at health and we see earlier signs of cardiovascular disease, metabolic syndrome, and shorter life spans."

An average woman aged 30-60 sleeps only six hours and 41 minutes during the workweek and as many as 61 percent of post-menopausal women report insomnia symptoms. In addition, an estimated 40 million American men and women suffer from sleep disorders which affect women more often than men. Sleep apnea—a sleep-related breathing disorder that causes individuals to repeatedly stop breathing during sleep—is one of the most common and affects approximately 18 million Americans, including one in four women over 65.

Another major player in the sleep interference game is shift work which takes place during non-traditional hours and is a way of life for about one in five Americans. Truck drivers, pilots, medical professionals, and factory workers may have challenges falling asleep or getting adequate sleep during the day when light and noise interfere and the impact of that may put lives at stake. Shift workers, in general, report more sleep-related accidents and illnesses. Family and down-time is strained which can also impact sleep quality.

The good news is that new research exploring women's sleep experiences and shift work may lead to specially tailored treatments. Another recent development according to Van Dongen is that today there is recognition that day and night is NOT the same in terms of work. "During the day, eight hours may be a perfectly acceptable amount of time for someone to work in a job that requires full focus for its duration (pilots for example or first responders) but that configuration is not the same if those hours take place during the night," he explains. "Sleep research has resulted in labor managers and federal agencies taking sleep deprivation into account when evaluating regulations so that jobs and work environments are safer. This is a wonderful advance."

To determine whether you might benefit from a sleep evaluation, the National Sleep Foundation suggests asking yourself the following questions:

  • Do you regularly have difficulty getting to sleep or staying asleep?
  • Has anyone ever told you that you snore or gasp for breath when you sleep?
  • Are your legs "active" at night? Do you experience tingling, creeping, itching, pulling, aching or other strange feelings in your legs while sitting or lying down that cause a strong urge to move, walk, or kick your legs for relief?
  • Are you so tired upon waking that you can't function normally during the day?
  • Does sleepiness and fatigue persist for more than two to three weeks?

If you answered yes to any of these questions, discuss having your sleep evaluated with your physician. Keeping a sleep diary and tracking any medications may be recommended before your visits. Sleep disorder specialists report great success in helping their patients—an estimated 85 to 90 percent get a better night's sleep with proper diagnosis and treatment.




Hans Van Dongen PhD research professor
Washington State University

National Sleep Foundation

National Institute of Health