To perform at your peak, you need to sleep seven to eight hours per night. If you don't get enough sleep, you can tax both your health and your productivity. Sleep loss is a major problem.
Stage 1: This is the lightest phase of non-REM sleep. It occurs when we first begin to nod off. At this stage our senses switch off so we no longer can hear noises or feel warmth or coolness. We can, however, be aroused from this stage of sleep by a sudden loud noise like a door slamming or the neighbors car alarm. Our brain waves during this stage are low-frequency Theta Waves.
Stage 2: During this stage of sleep the body temperature decreases and our breathing and heart rates even out. We also become more disengaged from our waking senses. Our brain waves alternate between short bursts which are called Sleep Spindles and large, sudden waves called K-Complexes.
Stages 3 & 4: These are the deepest stages of sleep. During these phases your blood pressure falls, breathing slows, and your body temperature drops even lower. These stages of sleep are also known as slow-wave sleep. These are essential stages of sleep because this is when your energy becomes restored. Also during these stages of sleep, your immune system is strengthened and your body is prompted to release vital growth hormones. During slow-wave sleep, your brain waves are wide, slow Delta Waves.
REM: This is known as Rapid Eye Movement sleep. During this phase of sleep, eyes dart back and forth, your breathing and heart rates flutter, and your muscles are mostly paralyzed. While we have vivid dreams about unrealistic events, parts of our brains are solving problems from the previous day and logging knowledge and experience into our long-term memories. During this phase of sleep, our brains are producing Beta Waves
Sleep Loss
A study by the National Sleep Foundation shows sleep loss is rampant in the United States...
39% of adults sleep less than 7 hours on weeknights.
36% of people over 15 years of age report having some level of insomnia.
54% of people over 55 report having insomnia once a week or more.
Traffic Deaths
A study by the National Sleep Foundation and the National Highway Traffic Savety Administration found...
70,000 Average crashes with injuries caused by drowsy drivers each year.
1,550 Average fatal crashes caused by drowsy drivers each year.
51% Adult drivers who admit they drive drowsy.
17% Drowsy drivers who fell asleep at the wheel at least once in the past year.
Deep Sleep
The University of Chicago did a study showing sleep depravation worsens as the population ages...
17% Age 25-35 in 1990 15% Age 35-45 in 1990 17% Age 60+ in 1990 14% Age 25-35 in 2000 16% Age 35-45 in 2000 21% Age 60+ in 2000
Recent studies suggest a strong link between sleep loss and disease.
Men whose sleep was restricted to four hours a night for six nights lost 30% of their ability to secrete insulin, suggesting a link between sleep loss and diabetes.
Women who slept five hours or less per night over a 10-year study period increased their risk of developing coronary heart disease by 30%.