Yoga is certainly demonic.

 Now on wards, I am strictly writing about Yoga as strictly physical exercise.  Yoga was developed and first taught by Hindu deity 'Shiva'. Google image search Shiva, certainly demonic.  If you are a Christian, then you may be knowing that There is not a single verse in the Holy Bible  that says directly that you have to do any certain physical exercise to be healthy.
   Yoga exercise is mimicry of animals' most aggressive poses.  bible does not say any word animal, but refer animals as 'beasts' throughout the Bible. ou know who is beast. Also, when Jesus cast out demons they went into pigs. That is a proof that animals have demonic spirits in them. Now search mimicry. It is the best way to communicate animals. Now combine all the above facts and search the words shamanism, spirit animals. You have your answer here.  Simply, Yoga poses mimic animals' most significant poses and when a you do it, you are indirectly communicating with that animal. Well to be more clear, you are indirectly communicating with the evil spirits in the body of that type of animal. When you do such difficult yoga pose, you lose your focus on Jesus/worship song you are playing as an excuse to do Yoga. For that moment when you empty your mind from Jesus, you are INDIRECTLY opening yourself to that specific demon in that animal whose pose you are doing. From that moment, that specific evil spirit slowly and steadily controls your soul (not your spirit) and you start to lose interest in The Word of God. You sin more and more. And this happens very very slowly and you do not even recognize it.
The most famous Western Christian Yoga pose is 'cobra' position. It is said in Hindu scriptures that Yoga is designed to awaken the serpent (kundalini) spirit in you which is coiled at your spine.  By doing Yoga you are surrendering your body to demons and so they give you healing and health power. Of course you feel good after doing yoga and so after you do drugs. Yoga becomes addiction after some time. Yoga is not a belief that you could separate it from exercise. Yoga is a demonic technique (such as Witchcraft) to invite unclean spirits in your life.
In 1 Timothy 4:1 God said, "Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils".
Yoga is doctrine of devil Shiva. Do you still want to follow it?
If you still disagree, then ask Jesus HIMself to show you the right path. Ask him,.....