Biorhythms are inherent cycles which regulate metabolism, coordination, emotions, sexuality, memory, and more. We have 3 fundamental biorhythm cycles. Each biorhythm cycle has a particular life span.

Our physical cycle completes one life span (or cycle) in 23 days. The emotional cycle lasts 28 days, and the intellectual cycle lasts 33 days.
At mid point, and end point in each cycle, the cycle sharply moves back to zero point and changes polarity, thus creating a transition day (also called a critical day, or caution day). That's all there is to it!  As each cycles changes polarity, we experience life's ups and downs!

Biorhythm cycles are as follows:

• Physical Cycle (RED) 23 days The physical cycle is the dominant cycle in men. It regulates hand-eye coordination, strength, endurance, sex drive, initiative, metabolic rate, resistance to, and recovery from illness. Surgery should be avoided on physical transition days and during negative physical cycles.
• Emotional Cycle (BLUE) 28 days The emotional cycle is the dominant cycle in women. It regulates emotions, feelings, mood, sensitivity, sensation, sexuality, fantasy, temperament, nerves, reactions, affections and creativity.
• Intellectual Cycle (GREEN) 33 days The intellectual cycle regulates intelligence, logic, mental reaction, alertness, of direction, decision-making, judgment, power of deduction, memory, and ambition.