The Mishnah Berurah writes that one should not jump out of bed as soon as he awakens, but
wait a few moments and then jump out of bed.
In the year 1998 there was a neurology conference, and there was a discussion about a feeling
of faint that people have in the morning hours. At the conference, Professor Linda from Cameron,
Britain, spoke about many researches she had done on this topic, and had come to a
conclusion that it has to do with not waiting before getting out of bed. She found that it takes
12 seconds for the blood to go from the feet to the brain, and getting out of bed before this
causes a weakness in the body. Afterwards, a Jewish Professor got up to speak and said by us
we have an old custom to say a prayer of thanks for awakening with good health, and this
prayer has 12 words!