This piece is the first of a multi-part Future of Cyclical Work essay series (to be released periodically this winter), written by a number of different authors exploring the intersection of cycle literacy and organizational design.
Aligning work with women’s natural rhythms
In 1729, Jean-Jacques d’Ortous de Mairan noticed that even in darkness, the leaves of the Mimosa pudica still opened and closed on schedule. Without sunlight, this heliotrope plant kept time with an internal metronome.
Humans also live by multiple internal clocks: the circadian rhythm - a 24-hour loop of wake, sleep, and alertness–and infradian rhythms like the 28-day hormonal cycle underpinning the menstrual cycle. One moves like the minute hand: fast, predictable, tied to the day. The other is slower, subtle but powerful, choreographing energy, mood, metabolism, and even brain architecture.
Modern life–especially workplaces–tends to tune to the clock of the circadian rhythm, and we treat the infradian rhythm of the 28-day hormonal cycle as a footnote. But living by one is like hearing only one section of an orchestra.
I didn’t always know I was living by two clocks. But then I noticed patterns: weeks where I wanted to be everywhere–rooftop parties, double-booked dinners, pitch meetings followed by weeks when I craved being home, in dim light and sweaters. I once thought it was burnout, but it was a monthly rhythm, not a flaw.
Science agrees. In the follicular and ovulatory phases, rising estrogen boosts verbal fluency, creative momentum and social ease. In the luteal phase, progesterone rises and then drops, lending itself to deep-focus work and a craving for solitude. Menstrual weeks can be quieter, primed for reflection and reset.
A 2023 Nature study by Max Planck Institute researchers found the hippocampus changes volume across the menstrual cycle due to ovarian hormone fluctuations—shifts one can feel physically and emotionally. And these monthly arcs layer over daily circadian peaks: mid-morning highs, dips after lunch, late afternoon rebounds. The daily wave is the tide; the infradian cycle is the season. Together, they map your energy.
Athletes are already experimenting with both internal clocks in performance. For example, in the UK, the premiere league Chelsea F.C. Women players tailor training regimens to their menstrual cycles to improve recovery and reduce injury. The principle is clear: you achieve more when you move with your biology, not against it.
But you don’t have to be a professional athlete to harness this strategy. Your ovulatory week might be ideal for hosting events, pitching big clients, or photo shoots. Luteal weeks for editing, detail work, or tying up loose ends. Menstrual days for strategic thinking and writing: the kind that requires stillness to nail.
The point isn’t to create a color-coded master plan but to stop sanding yourself down to fit a 24-hour mold. Some workplaces optimize lighting for circadian alignment but the 28-day hormonal cycle and how it affects output, creativity or burnout has yet to find its place in organizational design conversations. For employers, understanding these rhythms could mean higher employee productivity, morale, and fewer sick days. Because if you’re running two clocks, the one-size-fits-all workweek isn’t just outdated, it’s inefficient. It flattens natural peaks of performance and ignores predictable dips. It ignores women.
Nobel laureate Claudia Goldin’s research shows that structural inflexibility in certain professions, not differences in ambition, drives much of the gender pay gap. She coined the term “greedy jobs” for highly compensated jobs requiring long, inflexible hours. If uninterrupted availability remains the highest currency, then anyone whose biology runs on more than one clock is at a structural disadvantage–expected to match the pace of a straight line while moving in an arc.
When my co-founder and I partnered with an independent clinical lab to study the efficacy of our plant-based capsule, formulated to support the different phases of the menstrual cycle, we were curious about how this innovation might influence women’s work lives. By the end of Cycle 2, in an IRB-approved open-label study of 40 women aged 18 to 45, the lab reported a 74% reduction in period-related sick days, and 72% of participants experienced less severe menstrual or premenstrual pain. We were encouraged by these early findings, though we know they only begin to reveal how greater cycle literacy and deeper research into women’s health, can enhance not just individual well-being, but the design of workplaces built for cyclical productivity.
A dual-clock workplace could mean rethinking schedules in monthly rather than weekly increments: building in meeting-light weeks during lower-energy phases, timing big presentations for high-estrogen windows, and granting employees more private autonomy over when they work best. Chronobiology in the office isn’t new. Forward-thinking companies already let employees who are “larks” or “owls” start and end their days at different times based on their natural chronotype, as inspired by research on 24-hour circadian rhythms. Extending that same logic to the 28-day hormonal cycle could add an even more nuanced layer to how we design for organizational well-being and performance.
When Henry Ford created the five-day week in 1922, one in five U.S. workers were women. Today, it’s one in two. Moreover, technological advancement has enabled remote, asynchronous and global communication while automation has allowed a shift from manual labor to intellectual, knowledge-based work. The AI revolution is causing even more rapid and dramatic shifts in augmenting human capabilities and driving efficiencies. Given these new variables requiring an overhaul of traditional workplace design, if Ford were designing for the modern workplace, couldn’t the 28-day cycle stand alongside the five-day week as a reasonable yardstick for time and productivity?
Living by both clocks isn’t about doing less; it’s about pacing for the right seasons. After all, in the wild, animals and plants obey their internal timepieces. Human beings are in fact the anomalous species here; our civilization and lifestyle with its myriad advances has in fact caused widespread disruption to our own intrinsic, endogenous rhythms. Think of alignment to biological rhythm not as an indulgence but a restoration for peak performance. Maybe nature had it right all along: it’s simply good design.
What would change if workplaces ran on both clocks?
About the Author
Lawyer turned wellness entrepreneur, Terry Chang once measured productivity in tenths of an hour. Now she measures energy in cycles and creativity in seasons. As co-founder and CEO of Two Moons Health, she believes cyclical living isn’t indulgence - it’s simply good design.
Works Cited
De Mairan, J. (1729). Observation botanique. Hist. Acadm. Roy. Sci., 35–36. https://www.scirp.org/reference/referencespapers?referenceid=2374585
Barnes, Christopher. “The Ideal Work Schedule, as Determined by Circadian Rhythms.” Harvard Business Review, 2015.
https://hbr.org/2015/01/the-ideal-work-schedule-as-determined-by-circadian-rhythms
Nature Scientific Reports. “Menstrual cycle rhythmicity: metabolic patterns in healthy women.” 2018.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6167362/
The Independent. “Chelsea become first football club in the world to tailor training to players’ menstrual cycle.” 2020.
https://www.the-independent.com/life-style/women/chelsea-fc-women-menstrual-cycle-training-wsl-emma-hayes-players-a9335356.html
Goldin, Claudia, Career and Family: Women’s Century-Long Journey toward Equity, Princeton University Press, 2021. https://press.princeton.edu/books/hardcover/9780691201788/career-and-family
Peeples, Lynne, referencing Joseph Bass, circadian scientist, in The Inner Clock: Living in Sync with Our Circadian Rhythms, Riverhead Books (2024). https://lynnepeeples.com/the-inner-clock/