So, what are biorhythms?
Everything that happens around us in the nature is periodic. We are influenced by cyclic changing of the seasons, moon shape, day and night etc.
Every human life is influenced by these factors and 'works' periodical way as well. Scientists have discovered body cycles that are known as biorhythms. These cycles can influence things such as: coordination, immunity to disease, strength, mental stability, moods, logic thinking, ability to learn, memory recall, instincts, etc.
Charting your biorhythms can give a very real indication about your capabilities at a given time.
There are four known biorhythm cycles: physical, emotional, intellectual and intuitional . Each of these cycles starts at the time of birth. From this point, each of the cycles starts to rise up through its active phase until it falls back to the zero level. Then it continues through the zero level to go on to a passive phase. Then it raise again to the zero level to begin all over again.
Each time the cycle crosses the zero level from the active to the passive phase, it is said to be in a critical state (critical day).
When the cycle crosses the zero level from the passive to active phase it is said to be in a zero state (zero day). In the active phase the abilities associated with the particular cycle are high. When the cycle is in its passive phase the abilities are diminished.
During the critical day the associated abilities are unstable, and you should be really careful during that day. The 'zero day' can be various. The abilities are unstable during that day as well.
However this day is better than a critical day because the cycle is heading towards the active phase.
In practice we are under influence of the combination of all the cycles.