Sleep Encyclopedia of Type A Blood

Interesting talk about blood type: ( blood type and personality http:///xx/)

Human sleep is divided into several stages: falling asleep, light sleep, deep sleep, and continuous deep sleep. The length and quality of deep sleep are directly related to the lack of body rest. People with blood type A usually do not relax their nerves even if they fall asleep. They are in an early warning state and spend less time in "deep sleep" than people with other blood types, and naturally they are the ones who sleep the hardest.