Restorative yoga poses help us learn to relax and rest deeply and completely. The asana practice focuses on the yin energy, so the poses are meant to be held for a longer period of time without the use of muscle force. The body learns to let go of using tension in the muscle in order to avoid pain. So we learn to deal with our fears and the body reaction connected to that. Our mind is going to be outflanked.
During deep relaxation, all the organ systems of the body are benefited.
The reduction of muscle tension helps to cure insomnia and generalized fatigue. At the same time the reduction of the blood pressure helps to calm the mind and find peace.