When you feel your muscles tensing up, ask yourself, "Why am I tense?" Really think about it. Think about why they may want to. At this point, you may realize that there is no reason, and you can relax.
Take everything your body does as feedback, and as a signal to do something different. If doing it EXACTLY the way the program says is uncomfortable for you, find a way that uses the same methods but that you're comfortable with.
