The optimal number of hours of sleep individuals need varies from person to person and changes over time. Some may need as little as four hours of sleep, while others need as much as nine. These individual differences depend on factors such as age, sex, and previous sleep habits, as well as genetic and physiologic factors.

Nonetheless, amount of the time spent sleeping is decreasing: the average amount of sleep reported for middle-aged people in the late 1050s—around eight to nine hours—has decreased in recent times to about seven or eight hours. And the number of individuals who sleep less than six hours each night has significantly increased. These changes in sleep patterns may be indicative of sleep deprivation in society at large. This is not surprising, as the modern society seems to offer twice as much work (on the job, at home, etc.) and half as much time to complete it. Consequently, we are awake for extended periods of time, thus reducing the amount of time we spend sleeping.

However, we all know that sleep is essential! Sleep is vital to restore and renew many body systems; and sleep deprivation may result in poor performance, increased sleepiness, reduced alertness, delayed response time, difficulty maintaining attention, decreased positive mood, and increased long-term health risks. Some research studies have even shown that sleep deprivation is associated with increased risk of death.

So adequate sleep is vital for everyone to optimally perform the activities of daily living. But you may wonder, “How can I determine how much sleep I need to function at my best?” Dr. Michael Bonnet, director of the Sleep Laboratory at the Dayton. Ohio, Department of Veterans Affairs Medical Center provides a very simple but practical test you can use to determine how much sleep you need. According to him, if you need an alarm clock to wake up, try going to bed a little earlier the following night (e.g., 15 minutes earlier). If you still need an alarm clock to wake up the next morning, push your bedtime a little earlier again (i.e., another 15 minutes). Continue doing this until you no longer need an alarm to wake up.

I actually tried this test and found out I was not the “night owl” I thought I was. It looks like I function at my best if I retire for the night a couple of hours earlier than I used to. Sleep is important! It significantly affects your performance, health, and quality of life. And it is especially important to Warfighters, who can rarely get enough when deployed. So in addition to a healthy diet and regular exercise, try to get enough sleep each night whenever your situation makes it possible.

Sources: MedicineNet.com, National Sleep Foundation