Three repeating cycles in everyone’s life that begin at birth. The physical cycle has 23 days, the emotional cycle has 28 days and the intellectual cycle has 33 days. The cycles go through high and low points. Low points are called “critical days” and you are advised not to do things associated with the cycle on those days. Days when two or three cycles are critical are especially serious. Although the existence of human cycles has long been recognized and accepted, the validity of biorhythms has been questioned.