Secondary Biorhythm Cycles
The system of three fundamental cycles — physical (23 days), emotional (28 days), and intellectual (33 days) — has generated, over the decades, a series of extensions proposed by different authors and practitioners. These secondary cycles, also called extended cycles, claim to map more subtle dimensions of human experience: intuition, aesthetic sense, spirituality, awareness, and self-mastery.
Their epistemic status is even weaker than that of the three basic cycles: less well defined theoretically, never seriously studied empirically, often built speculatively. Yet they continue to be used by practitioners and applications, and they deserve to be understood for what they are.
Origin of Secondary Cycles
The Absence of Clear Historical Founders
Unlike the three primary cycles that can be linked to identifiable researchers (Fliess, Swoboda, Teltscher), the secondary cycles have much murkier origins. They appear to have emerged gradually in popular biorhythm literature from the 1970s onward, driven by practitioners who sought to enrich the basic system.
Among the authors frequently mentioned in extended cycles literature:
- Bernard Gittelson (author of "Biorhythm: A Personal Science," 1975) popularized the idea of extending the system beyond the three classic cycles
- Hans Regel and other European researchers of the 1980s proposed various extensions
- New age schools and wellness practitioners subsequently integrated these cycles into their practices, often mixing varied inspirations
The exact genealogy of each secondary cycle is difficult to trace — which should already give pause about their grounding in a coherent tradition.
The Intuitive Cycle — 38 Days
Definition and Domain
The intuitive cycle, lasting 38 days, is presented as governing the capacity for intuition, premonitions, extrasensory perception (according to some authors), and the connection to unconscious information processing.
During the high phase (days 1 to 19), promoters suggest:
- More reliable and accessible intuition
- More accurate premonitions
- Greater ability to read situations and people
- More frequently noticed synchronicities
- Facilitated access to inner wisdom
During the low phase (days 19 to 38):
- Intuition would be less reliable
- Premonitions less clear
- Greater dependence on conscious logic recommended
Critical Analysis
The concept of a 38-day cycle governing intuition raises several fundamental problems:
- Absent operational definition: intuition is not defined in a measurable way. Without an operational definition, no study is possible.
- Speculative biological mechanism: no known physiological process would produce 38-day oscillations specifically linked to intuitive processing
- Confusion with other phenomena: what is described as "intuition in high phase" closely resembles the description of the emotional cycle's high-phase effects (openness, heightened sensitivity)
The Aesthetic Cycle — 43 Days
Definition and Domain
The aesthetic cycle, lasting 43 days, claims to govern sensitivity to arts, beauty, expressive creativity, musical appreciation, artistic abilities, and sense of design.
High phase (days 1 to 21.5):
- Artistic and aesthetic sensitivity at its peak
- Expressive creativity facilitated (painting, music, writing, dance)
- More refined and discriminating taste
- Amplified aesthetic pleasure
- Ease in finding beauty in the everyday
Low phase (days 21.5 to 43):
- Aesthetic sensitivity diminished
- Expressive creativity more labored
- Less confident aesthetic judgments
Relationship with Primary Cycles
It is notable that the intellectual cycle (33 days) already covers part of the territory claimed by the aesthetic cycle — creativity being frequently mentioned as a manifestation of the intellectual high phase. Similarly, the emotional cycle (28 days) claims artistic inspiration.
This conceptual redundancy is typical of systems built by sedimentation, where new layers are added without questioning overlaps with existing ones.
The Spiritual Cycle — 53 Days
Definition and Domain
The spiritual cycle is one of the longest secondary cycles, lasting 53 days. It claims to govern spiritual connection, the sense of belonging to something greater than oneself, transpersonal consciousness, and mystical or deep flow states.
High phase (days 1 to 26.5):
- Amplified sense of spiritual connection
- Prayers, meditations, and contemplative practices deepened
- Synchronicities more frequent and meaningful
- Reinforced sense of meaning and purpose
- Easier access to flow and presence states
Low phase (days 26.5 to 53):
- Feeling of disconnection or spiritual dryness
- Contemplative practices more labored
- Possible sense of existential emptiness
- Difficulty finding meaning in daily events
Cultural Context
The spiritual cycle reflects a period of growing interest in spirituality in new age and personal development circles of the 1980s-1990s. Its integration into biorhythm systems illustrates how this framework of thought was used as a container to organize very diverse subjective experiences.
The period of 53 days itself seems to have been intuitively chosen to produce a cycle long enough to be "serious" while distinguishing itself from other cycles by its value.
The Awareness Cycle — 48 Days
Definition and Domain
The awareness or awakening cycle, lasting 48 days, is presented as governing self-awareness, inner awakening, the capacity for presence and mindfulness, as well as clarity about one's own life path.
High phase:
- Heightened self-awareness
- Clarity about one's values and life direction
- More accessible capacity for momentary presence and awakening
- Finer perception of relational dynamics
- Better access to personal insights and revelations
Low phase:
- Inner fog
- Difficulty feeling present
- Stronger automatic reactivity
- Less perspective on one's own experience
Distinction from Other Cycles
The overlap with the intuitive cycle (38 days) and the spiritual cycle (53 days) is obvious: all three claim to govern aspects of "expanded consciousness." This multiplication of cycles in the register of inner consciousness seems to respond to a cultural demand rather than a theoretical necessity.
The Composite Mastery Cycle
Definition
Some practitioners propose a composite mastery cycle obtained by combining the physical cycle (23 days) and the intellectual cycle (33 days):
T(mastery) = 2 × T(physical) × T(intellectual) / (T(physical) + T(intellectual)) ≈ 26.9 days
Others use simply the arithmetic mean or the product of the two cycles. The lack of standardization in the calculation illustrates the artisanal nature of these extensions.
The mastery cycle is supposed to govern the capacity for excellence in a discipline, the coordination between physical competence and tactical intelligence — particularly valued in martial arts and high-level sport.
Summary Table of Secondary Cycles
| Cycle | Period | Domain | Origin | Validation |
|---|---|---|---|---|
| Intuitive | 38 days | Premonitions, unconscious perception | Popular literature, 1970s-80s | None |
| Aesthetic | 43 days | Arts, beauty, expressive creativity | Various practitioners | None |
| Spiritual | 53 days | Transpersonal connection, meaning | New age circles | None |
| Awareness | 48 days | Awakening, presence, inner clarity | Wellness syncretism | None |
| Mastery | ~27 days | Excellence, mind-body coordination | Composite calculation | None |
Why Do Secondary Cycles Persist?
Response to a Real Need
Despite their lack of empirical grounding, secondary cycles respond to an authentic human need: mapping inner experience. Humans genuinely go through periods when their intuition seems sharper, when their creativity flows more easily, when the sense of spiritual connection is more present.
These variations are real — but attributing them to cycles of specific lengths is a cultural projection, not a scientific observation.
The Comfort of Structure
Cyclical systems offer a reassuring temporal structure. Knowing that the current "spiritual dryness" is part of a 53-day cycle and will pass naturally can reduce anxiety and avoid catastrophic interpretations. This is a legitimate psychological function, independent of the model's empirical truth.
The Narrative Effect
Secondary cycles allow the construction of a coherent narrative around subjective experience: "I am in aesthetic low phase — that's why my creativity is blocked." This externalization can paradoxically release performance pressure, but it can also become an excuse that prevents investigating the true causes.
An Honest Approach
Secondary cycles must be presented with complete candor:
- They are not validated — no serious study supports them
- Their origins are murky — no identifiable founders or coherent theory
- Their definitions overlap — the same experiences are claimed by multiple cycles
- They may nonetheless be useful — as symbolic reading grids, as invitations to introspection, as personal narrative tools
The distinction between "useful" and "true" is fundamental here.
Connection with Shinkofa
Shinkofa adopts a transparent position on secondary cycles: they are available in the interface for users who wish to explore them, but clearly distinguished from primary cycles by a badge indicating their speculative status.
Shinkofa's philosophy is that of the open toolbox: offering access to diverse knowledge systems, with clearly signaled validation levels, and letting the user build their own practice. Secondary cycles can enrich personal reflection for those who find resonance in them — as long as one never forgets their hypothetical nature.