What do you think about Yoga as a relaxation activity

l can't talk about Yoga as a relaxation activity because I have never done Yoga. However, I watched Yoga program on TV. I think it is good for muscle streching, but I'm not sure whether it is good for relaxation or not.When I want to relax,I read a bible and pray to God " God, I want relax" and then I can get peace in mind,feel relaxed. If I need relax, immidiatly pray to God.