Body rhythms

The processes of the body sync to rhythms

Our physical bodies are a lot less solid than they seem.

Biological molecules and systems are made up of moving energies in continuous interaction. These energies flow in time, participating in the ongoing processes of life.

To function smoothly over time, the body relies on rhythms.

These rhythms happen on many different time scales. Some are incredibly small—like the vibration of molecules. Others are larger, such as the steady beating of the heart. Hormones are released in rhythmic pulses. The brain also follows its own rhythm, sparking with the waves of electrical activity. And of course, we have a daily rhythm—our sleep-wake cycle—that guides us from alertness to rest.

All of these rhythms are interconnected. They sync with each other and with cues from the world around us.

You can think of the body’s rhythms like an orchestra: each function plays its own part, but they stay in harmony by listening and responding to one another.

These rhythms are essential. They help ensure that the right processes happen at the right time. When everything is in sync, the nervous system can send messages more clearly, and the whole body works more smoothly. Rhythm forms the foundation of communication between body and brain.

Importantly, the body’s rhythms can naturally fall into sync—if we give them the space and consistency to do so. Having a stable baseline rhythm allows other body functions to align and flow more effectively.

The circadian rhythm

One of the most important baseline rhythms in the body is the circadian rhythm. This daily cycle is closely aligned with the rising and setting of the sun, lasting about 24 hours. It helps coordinate a wide range of functions—such as brain activity, metabolism (how the body uses energy), hormone release, mood, energy levels, and even when the bowels and bladder are most active.

Rhythms and symptoms

We can see how important rhythm is for our health by looking at what happens when it gets disrupted. Most of us have felt the effects of jet lag—when our internal body clock falls out of sync with the sun after crossing time zones. People who work night shifts often experience similar symptoms. These can include fatigue, insomnia, digestive issues, and problems with mood or focus.

Although studying these rhythms can be challenging, some doctors and researchers believe that common functional symptoms, like chronic fatigue, may have a lot in common with jet lag. This idea is supported by the experience of many people: when they follow a consistent daily routine that helps reset or “entrain” their circadian rhythm, their symptoms often begin to improve.

Entrainment

Bringing bodily rhythms back in sync is called entrainment. Research tells us that to get our rhythms back on track, we need to expose our bodies to certain cues at the same time every day for several days.

The good news is that the most powerful cues to entrain body rythms are widely available and free.

Morning sunlight, especially the blue light from the sun in the first three hours after sunrise, is a crucial cue that resets the circadian rhythm. Spending most of the day indoors has become so normal in modern life, that we don’t think about how this weakens the circadian cues our bodies receive.