Old thread made a comeback?
Anyway, Yoga doesn't hurt, as long as you do what is within your capabilities and stay reasonable. But you will feel strain and feel uncomfortable, and of course have some sore muscles the day after a more powerful session.
The point though is that all those feelings will go away or be reduced a lot after doing Yoga some time. When you master a yoga position you will be quite relaxed when moving in and out from that position. As a beginner one struggles with coordinating breathing, muscle control, the inflexible muscles, poor core strength and balance, etc which makes it hard. It's a joy to see someone doing the triangle A and B with perfect control and no effort.
cheers Porphy