The quality of sleep is not depended on the length of time but by the quality of sleep. The sleep which plays a decisive role on human health is the "deep sleep" at night. Quality of 6 hours' deep sleep is much higher than 12 hours' light sleep. "Deep sleep" is the best and deepest stage of human sleep. You can not hear any noise outside at this moment and it is difficult for others to wake you up. After you wake up, you will feel refreshing. At this moment, hormone in your body experiences plenty of secretion. Immune cells and a variety of damaged cells (especially brain cells) are in rehabilitation; fatigue disappears and the energy is in the storage; the digestive system is busing in absorbing nutrients materials; large wastes are discharged. "Deep sleep" makes it assurance that children grow tall and their intellectuals develop; young man is full of energy; middle-aged people enjoy good health; elderly enjoy health and longevity.
iPhone OS 3.x
||Requires iPhone OS 3.0