The video found at the website below describes the amazing health benefits of prayer. 
What is your definition of prayer? I have changed my definition as I moved from my head to my heart! I was taught the Lord's Prayer as a child and used to say it in an intellectual, rote manner. When I had my spiritual awakening, the same prayer spoken from my heart had a drastically different effect. The power and presence of the Beloved is directly experienced when heart-fully saying the light filled words given from Yeshua.
Matthew 6:6 says to go into your heart, close the door to your external senses, and let your heart speak to God in silence and stillness. Prayer is listening to the still, small voice of God. Prayer is intimate connection to the One. Prayer is seeing from the highest view, the highest perception, the higher thoughts of the Beloved. Prayer is directing your mind to the heart. Prayer is focusing your attention and intention to the heart to commune with God.


http://w3.newsmax.com/newsletters/mhr/prayer_video.cfm