The biorhythm theory says that our lives are influenced by recurring cycles, which determine organism functioning, physical and emotional states. These cyclic patterns are believed to occur at different time periods. It is believed that every individual has a 23-day physical cycle, a 28-day emotional cycle, and a 33-day intellectual cycle. Whether you are truly interested in this theory or are just curious about it, then you can try the Biorhythms application.  

No installation is needed and the simple one-window GUI will be shown to you in a second after launch. You start by creating a new profile, where you must enter a custom name and your date of birth. There is no need for anything else, as the graphs are generated automatically. 
The application starts calculating your age, both in number of days and years. The current day of each cycle is shown right alongside the graphical representation of all the cycles.

By default, the application reveals four cycles, namely physical, emotional, intellectual and intuition. While these are the four axes that are believed to occur in a person’s life, the Biorhythms application can also generate a representation of the spiritual and the aesthetics biorhythm.

You get to see the trend in your cycles and compare them with the periodical cycles of various celebrities, just for the fun of it. Alternatively, you might start to understand your own states, feelings and behavior once you learn more about biorhythms and how they affect us.

To find a pace that suits your biorhythms, you first have to understand how they work and monitor them closely. Who knows, you might make some connections and start getting more and more curious about this theory which many use in their daily lives.