In order to be an active thinker, it helps to keep an active body. Especially for a sign which tends to get bogged down by the inequalities of everyday life. Try thinking of exercise as something the body deserves. When your mind wants to talk you out of it or wants to convince you that procrastination is OK, remember that the body can be ignored by the mind (up to a point) and you must be the champion of the silent and oppressed! It's only fair.