Americans are clock-watchers, we don't sleep enough and ignore, the clocks we should be watching, our biological clocks. Our schedules do not allow enough time for work, family and play, so we borrow the time from sleep. Many Americans suffer from moderate or severe daytime sleepiness. Concentration, decision-making, problem solving and performance are adversely affected. (USAMRMC 2002). .
Humans have biological rhythms, 24-hour cycles in tune with exposure to daylight, knowledge of clock time, meals and schedules. People are more alert during the day than at night, and research has shown people not only feel sleepier at nighttime, but perform more poorly as well. .
Forty percent of adults say their daily sleep is inadequate. People go to bed too late and get up too early or don't sleep well due to stress. Rotating shifts lead to poor or inadequate sleep. Of the 25 million shift workers in the United States, many find it impossible to stay alert during their night jobs because sleeping during the day does not match body's biological clock. Many of the sleep-deprived people in America are in the military. (Caldwell 2002).
Commanders place a high value on troops who "Suck it up and drive on" despite the fact that these individuals are increasing accident risks because they are suffering from dangerously low levels of alertness. Many adults feel fatigue is part of the price to be paid for being successful. Some see fatigue as a badge of honor rather than a serious problem in need of attention. .
We are not always aware of how fatigue affects alertness and performance. Recent studies have linked performance while fatigued to performance levels associated with alcohol use. 18 hours without sleep causes mental and motor skills to deteriorate a much as they do when blood alcohol concentration (BAC) reaches 0.05%. Twenty-four hours without sleep equates to a BAC of 0.10%, the legal limit in all 50 states.