Dawn and dusk chase each other daily as does summer and winter. These are natural cycles of life. When these cycles happen in a human body they are called “biological clocks.”
According to the biological clock theory, every rhythm within the body has an order. Your heart beat, your breathing patterns and body temperatures are a few aspects of these internal rhythms. Some peak during the day and some at nights.
Another name for the biological clock is “circadian rhythms.”
We are not separate from our environment. Many of our rhythms match or are influenced by the rhythms of our surroundings. Sleep is a good example. In nature as it gets dark we prepare to go to sleep. Some of our rhythms continue even when we are placed in isolation.
Some experiments indicate that the body’s inner clocks would not change even if a person was isolated for weeks from any social or physical cues, such as a regular meal or light-dark cycles.
Body temperature is a well studied circadian rhythm. In a healthy person, it is at its lowest in early hours of morning and peaks in the late afternoon. The relative change is independent of routines.
Blood sugar level also decrease by noon. Around 3:00 a.m. to 6:00 a.m. your body has depleted much of its sugar supply. This is one reason many suggest early morning aerobics workouts so that your body burns fat since it has very little sugar to burn.