About six-hrs. or so,...is good for me, Plus I do a half-hr. NAP at about mid-day. Also, try this chi-gong sleep-method. Lie on your back with your hands at the middle & lower dan-tiens'(men left-hand at lower dan-tien, women right-hand at lower dan-tien),..and put the soles of your feet together,..it is a very restful, deep, warm sleep. Hao Kao!, Coach Li