I think with the concept of yoga, it totally depends on how you use it and what expectations you have of it. If you want to use yoga as an exercise then you'll experience it differently... If you use yoga as a tool to enhance one's consciousness, then you will also experience it differently. Similarly, if you use meditation/naam simeran and have an expectation to reach a higher spiritual level, then your experience of it will be different again. What I believe is that with any of these methods, we should not have any expectations. For example, if we are doing naam simeran, and we only do it because we think we'll reach God, then it's not as effective than if you're doing simeran from your heart and soul without any expectation - but you're doing it from pure love. So basically, my point is that Yoga can either be beneficial or useless to a person, depending on how they use it and how they practice it. If you use yoga as a way to connect to God and to remember our source of existence with every breath that you take in, then I don't think it's a problem, because it's just another method of meditation.