It is positive thinking to reserve a rest day for your body, mind, and spirit to recoup and heal. Sometimes if you push too hard, there is muscle damage, and you need to allow healing. 1 day a week, I stretch, and may or may not do light cardio, but I give myself a much needed break. It works!
I schedule Friday as a rest day, but if I feel energetic, I will do a light cardio on the wii-fit plus. Sometimes I move it to Sunday. I find I am so worn out from my work week, that giving myself down time on Friday I am ready and willing to put in a good cardio on Saturday.