The theory of biorhythms was developed in the early 1900's by two European doctors working independently, Dr Wilhelm Fliess in Berlin and Dr Hermann Swoboda in Vienna. They observed that people follow active and passive cycles in their physical and emotional behaviour. The physical cycle lasts 23 days and the emotional cycle lasts 28 days. Later, Dr Friedrich Teltscher added an intellectual cycle that lasts 33 days.
Each cycle has two halves, active and passive or high and low, ranging from a best day to a worst day. When the cycle passses from one half to another, this is called a critical day. On critical days you are more prone to accidents, instability, errors and are generally off-balance.
HIGH Physical stamina, health and the general physical condition, good reaction to medicines.
CRITICAL Susceptible to sickness or accidents.
LOW Rest needed, recuperation, easily tired or strained.
HIGH Creativity, sensitivity, good mood and tolerance of others.
CRITICAL Susceptible to irritability and feeling on edge, easily hurt.
LOW Feels more depressed and frustrated. Easily drained by being around others.
HIGH Learning ability, self-confidence, clear thinking.
CRITICAL Susceptible to misunderstanding and arguments. Poor decision making. Confusion.
LOW Good for reviewing what you know rather than new ideas.