Cyclical Rhythms and Natural Health in South Africa: What Nature’s Timing Teaches Us About Our Bodies

Written by Sean du Plessis — Herbal Journeys

Cyclical rhythms and natural health in South Africa are more deeply connected than most modern routines allow for. Nature rarely moves in a straight line — day becomes night, winter gives way to spring, plants germinate, grow, flower, seed, and return to the soil. Activity is followed by rest. Yet modern life often asks something quite different of us: consistency. The same alarm. The same working hours. The same expected output, day after day.

A living body is not a machine designed to produce the same result at every hour of every day. It is rhythmic. And the second foundational principle guiding my approach to Traditional Western Herbal Medicine takes that seriously.

Nature Keeps Time

Plants are not simply responding passively to sunrise and sunset. They possess internal circadian clocks that anticipate daily changes in their environment, influencing photosynthesis, metabolism, growth, and events such as flowering (1, 2).

Humans have them too. Our circadian system produces rhythms of approximately 24 hours and coordinates sleep and wakefulness, hormone secretion, metabolism, body temperature, and many other physiological functions. Rather than one central clock controlling everything, clocks exist throughout the body and communicate with one another, with a timing system in the brain helping to synchronise them (3).

Light is one of the strongest signals setting this system. This is why morning and evening are biologically different experiences — not simply different numbers on a clock.

We Were Never Designed for Constant Daylight

For most of human history, bright light meant daytime and darkness meant night. Artificial lighting has changed that relationship dramatically.

Light reaching the eyes in the evening and at night can shift or disrupt circadian timing, though the effect varies with intensity, timing, duration, and wavelength (4). Research into the long-term health consequences of artificial light at night is ongoing, and some proposed effects remain less certain than popular discussion suggests.

The broader principle, however, is well established: our biology pays attention to when things happen. Sleeping at midnight is not biologically identical to sleeping at midday. Eating, exercising, and receiving light at different times interact differently with our internal clocks. Timing matters in ways we are only beginning to map fully.

There Is a Time for Growth — and a Time for Rest

One of the most valuable lessons nature offers is that growth is never continuous. A tree does not apologise for winter. A seed does not fail because it has not yet germinated.

Rest, dormancy, and decline are not interruptions to nature’s productivity. They are part of its cycle. We forget this when thinking about ourselves. We expect energy to remain constant despite illness, emotional difficulty, poor sleep, demanding work, or changing circumstances. Tiredness becomes something to overcome. Rest becomes something to earn.

But perhaps the better question is: what season is this person in right now?

There are periods in life suited to building, learning, creating, and expanding. There are also periods for recovery, consolidation, grieving, withdrawing, and simply maintaining what already exists. A cycle requires both. Neither is a failure.

Rhythms Within Rhythms

Human physiology contains many overlapping rhythms. The sleep–wake cycle is the most obvious, but hormones, immune activity, metabolism, and gene expression also shift across the day (3, 5).

Sleep itself is intertwined with circadian timing rather than being simply a period when the body switches off. Sleep pressure and circadian rhythms interact continuously to influence when we become sleepy, when we wake, and the quality of physiological recovery that follows (5).

These daily cycles sit within larger ones: stages of life, reproductive cycles, changing seasons, and the inevitable movement between activity and rest. We live within rhythms inside rhythms — and when those layers fall out of step with one another, the body registers it.

What This Means for Herbal Practice

This principle changes an important question in herbal medicine. Instead of asking only what support a person needs, we should also ask when it is needed.

When is their energy strongest? When do symptoms worsen? How do they sleep? What happens before those symptoms appear? Has their routine become disconnected from daylight, regular meals, or adequate rest? Are we offering support for activity when the body is asking for recovery?

Herbs do not exist outside time either. A stimulating herb in the evening and the same herb in the morning are not necessarily the same intervention in practice. Relaxing herbs, meals, exercise, rest, and light all occur within a biological day — and how they are timed shapes what they do.

Traditional practice therefore encourages observation. Not every variation requires correction. Sometimes the body is not malfunctioning. Sometimes it is simply cycling.

If you’re curious to explore how cyclical rhythms and herbal support might apply to your own health, you can explore events and practitioners on S.O.L.O — including herbalists, bodyworkers, and holistic health practitioners across South Africa.

Returning to Rhythm

Living by cyclical rhythms does not mean rejecting modern life or attempting to follow some imagined prehistoric schedule. It means remembering that beneath our calendars, deadlines, and electric lights, an older clock is still ticking.

We are organisms living on a rotating planet where light becomes darkness, and activity requires rest. Growth gives way to decline, and decline creates the conditions from which new growth eventually becomes possible.

Perhaps health is not about remaining permanently at our peak. Perhaps it is partly about learning to recognise the season we are in — and allowing ourselves to move through it.

Nature does not demand sameness. It asks us to participate in time.

View Sean’s profile on S.O.L.O and book a session →

References

1. Mortada, M., Xiong, L. & Mas, P. “Dissecting the Complexity of Local and Systemic Circadian Communication in Plants.” npj Biological Timing and Sleep 1, 1 (2024).
2. Wang, F., Han, T. & Chen, Z.J. “Circadian and Photoperiodic Regulation of the Vegetative to Reproductive Transition in Plants.” Communications Biology 7, 579 (2024).
3. Mortimer, T. et al. “Circadian Clock Communication During Homeostasis and Ageing.” Nature Reviews Molecular Cell Biology 26, 314–331 (2025).
4. Mendoza, J. “Circadian Disruptions and Brain Clock Dysregulation in Mood Disorders.” Nature Mental Health 2, 749–763 (2024).
5. Franken, P. & Dijk, D.-J. “Sleep and Circadian Rhythmicity as Entangled Processes Serving Homeostasis.” Nature Reviews Neuroscience 25, 43–59 (2024).