I have wondered if there might be a corelation between biorythms and lucid dreaming patterns.

The theory of biorythms is based on the creation and discharge of energy by living things and is a fundamental concept of biological theory. In the early 20th century three human energy cycles were observed that last 23, 28, and 33 days. The Physical cycle has a length of 23 days, its peak day is the 6th day of the cycle, the trough day is the 17th of the cycle, and the critical days are the 11th, and the 23rd day of the cycle. (More on peak, trough and critical days in a moment). The physical cycle affects a range of physical factors such as fitness, coordination, speed, adaptability, resistance to disease, healing, and basic body funtion.

The Emotional cycle has a length of 28 days with the peak falling on the 7th, the trough on the 21st, and critical days on the 14th and 28th. (Do not confuse cycle days with days of the month, as they are days into the cycle and do not fall on a specific date.) The emotional cycle affects perceptions, attitudes, prejudices, sensitivity, moods and general mental health.

The Intellectual cycle has a length of 33 days with the peak falling on the 8th cycle day, the trough on the 24th cycle day, and critical days falling on the 16th and 33rd. The Intellectual cycle affects abilities such as memory, alertness, learning, formation of ideas, and also analytical functions of the mind.

These cycles can be plotted on a graph (which I have provided a great link that I found today) as a sine curve. These waves represent the energy that is available for a given timeperiod and is calculated from your birthdate where it has been assumed that these cycles start at a single point.

A positive period is where the curve is above the baseline with the peak being the top of the curve. Conversely the trough or negative period will be the opposite, however it is when these waves cross the baseline in either direction that we are said to be at our most critical or vulnerable period in the given area.

The link that I had has been replaced with this new one courtesy of Chatter-Box. He found a much better one that will allow you to pick any report date that you wish to see! Excellent link!
http://mindbluff.com/bior.htm