Since the beginning of mankind, human history has been shaped by light and darkness. Genetically manifested timers reside deep inside our bodies control our body’s fundamental rhythm beyond our consciousness.
The more intelligently that we absorb, utilize, and sync our conscious being with this rhythm, the more effectively we can leverage our energy output and increase our success in every aspect of our life.
The Science of Time….Within Your Body
Chronobiology is a subset of biology that seeks to understand the cyclical phenomena in organisms and their adaptation to physiological rhythms.
Essentially, it seeks to find the biological patterns in all life. From anatomy and physiology to genetics, reproduction, and even our planet’s ecology.
The word chronobiology originates from the Greek root, chronos, meaning time, and bios logia, which is the study of life. Timing is essential for nearly all key biological processes, from sleeping to cellular regeneration, having a profound impact on one’s well-being.
Most often, we only hear about one of the timing cycles; the circadian rhythm, which is connected to the Sun’s patterns. The word circadian originates from the Latin words, circa, meaning around, and diem, meaning day, describing the solar cycle of one day.
Our sleep cycle is a pattern dictated by our circadian rhythm. Another, being the leaf movements of plants. Both depend on light to function; humans, to be active, and plants, to photosynthesize efficiently.
But as humans, it isn’t just our sleep cycle that isn’t dictated by a circadian rhythm. In fact, we all have a circadian rhythm that regulates our daily body processes, including digestion, metabolism, body temperature, and excretion.
These rhythms are synchronized with a master clock in the brain, a cluster of about 20,000 neurons found in the brain’s hypothalamus that keeps all of these internal processes in sync. This structure is called the suprachiasmatic nucleus, or the SCN.
Together, these circadian rhythms fall into natural sync, producing the symphony of human life.
This master clock is directly influenced by environmental cues, especially light, which is why circadian rhythms are tied to the cycle of day and night.
However, that was before Thomas Edison finally came around in 1879 and finally got his lightbulb to work. 💡
Clearly, light has propelled society in an unfathomable way. Our society would be nowhere near as advanced as it is now. But constant light has messed with our body’s natural biological rhythms.
After we’ve been given light, we have a choice. We can do anything we want, whenever we desire. We can choose to eat dinner at 11 pm, watch movies at 2 am, and spend our time working at ungodly hours. But this has lead to a multitude of physical, mental, and cognitive issues beyond our control.
In a 2014 paper in the International Review of Psychiatry, researchers were able to link circadian misalignment with an increased risk for developing cardiovascular disease, diabetes, obesity, cancer, schizophrenia, depression, bipolar disorder, ADHD. Further research has found even more conditions closely correlated with circadian disruption. In 2017, 3 scientists were even awarded the Nobel Prize for identifying the gene that controls our circadian rhythm.
We have thrown our circadian rhythms so off course that we are having to biohack our lives just in order to restore the damage we have done to our natural bodily functions.
Progressively, society has become increasingly more aware of this issue. Things like screen time limits and blue light glasses aim to subside the biological and functional costs that we pay on a daily basis through our constant tiredness and decreased productivity.
But the circadian rhythm isn’t the only biological clock out there.
Every individual with a female physiology also has an infradian rhythm.
In other words, 50% of our population has a second biological clock that we have been completely oblivious to.
The word infradian is derived from the Latin word, infra, meaning below, and diem, meaning day. Infradian signifies that the period of this rhythm is longer than 24 hours, and therefore, the frequency is lower, or below, one day.
Infradian rhythms last more than 24 hours, repeating only every few days, weeks, months, or even years. In the case of women, this occurs in the form of a menstrual cycle, repeating approximately every 28–35 days.
The menstrual cycle starts at puberty and continues until reaching menopause around the age of 50; having a prominent presence in an individual’s life for around 40 years. Just as how circadian rhythms play a significant role in daily bodily functions, the menstrual cycle influences the brain’s chemistry and physiology providing women with certain strengths at different times of the month.
However, both the circadian and infradian rhythms in women are tightly intertwined. Hormonal fluctuations controlled by the menstrual cycle affect body temperature, a circadian rhythm. On the contrary, any disturbance in the 24-hour clock can disrupt your menstrual cycle, leading to a plethora of issues such as irregular periods, PMS, and longer cycle lengths.
The Phases of the Menstrual Cycle
When we think of the menstrual cycle, we often just think of menstruation or a “period.” Every time you menstruate, the cycle simply repeats.
But there is a lot more to it than just that.
Menstruation isn’t just the process of ovulation and menstruation. In fact, there are 4 main phases that constitute the ovarian cycle:
Follicular: The time between the start of the menstrual cycle (with the onset of menstruation) and ovulation. Between 7–10 days long.
Ovulatory: The release of an egg from the ovaries, traveling through the fallopian tubes. Takes place 3–4 days following the follicular phase.
Luteal: The 10–14 days between ovulation and the start of menstruation, as the body prepares for a possible pregnancy.
Menstrual: The 3–7 days of your period, in which the uterine lining (lining of the uterus) is shed.
Follicular Phase (7–10 days)
Soon after the onset of menstruation, the hypothalamus, a small, almond-sized structure, stimulates the pituitary gland, a small, pea-sized gland controlling the function of the other endocrine glands while producing hormones of its own.
The hypothalamus calls on the pituitary gland to produce the follicle-stimulating hormone, known as FSH. The pituitary gland shuffles FSH to the ovaries to aid in the maturation of the eggs.
Each of your two ovaries, only about the size of a grape, houses around 300,000 eggs at the onset of puberty, a lifetime supply. Each egg is housed in a fluid-filled sac called a follicle. Upon the arrival of FSH, the follicles swell in preparation and prepare an egg for ovulation or the release of an egg from the ovary.
About halfway through the follicular phase, one follicle in one of the ovaries is the largest of all the follicles, reaching approximately 1 cm in diameter. This follicle becomes the dominant follicle and is the one prepared to be released at ovulation.
The dominant follicle produces estrogen as it grows, and estrogen peaks just before the onset of ovulation. The rising estrogen levels initiate the renewal of the uterine lining, known as the endometrium. The lining thickens in order to prepare for an ideal environment later on in the cycle.
Ovulatory Phase (3–4 days)
The dominant follicle in the ovary produces increasing amounts of estrogen as grows larger. Soon, the dominant follicle reaches about 2–3 cm in diameter; its largest size prior to ovulation. When the estrogen levels reach a threshold, they send a signal to the brain to ramp up the production of luteinizing hormone, which is released by the pituitary gland and triggers ovulation, the release of an egg.
The egg makes its way down the fallopian tube to the uterus where the uterus has grown a thick, lush lining of protective immune cells, thanks to the rise in estrogen.
Luteal Phase (10–14 days)
Once ovulation occurs, the follicle that once contained the egg transforms into a mass of cells called a corpus luteum, responsible for the production of progesterone and some estrogen.
Progesterone levels peak about halfway through the luteal phase, as do estrogen levels to keep the thickened uterus lining in anticipation of a fertilized embryo. The rise in progesterone signals the pituitary gland to stop the production of FSH and LH.
Menstruation (3–7 days)
If an egg is fertilized, progesterone from the corpus luteum supports early pregnancy, but if fertilization doesn’t occur, the corpus luteum breaks down and is reabsorbed with utmost efficiency.
This results in a drop in estrogen and progesterone levels, leading to menstruation. Often, this triggers premenstrual symptoms (PMS) such as mood changes, headaches, bloating, and acne as a result of too little progesterone.
The menstrual cycle is a constant symphony of hormonal and biological processes working to create life
Understanding Hormonal Advantages
It turns out, there’s a bit more to our biochemistry than we thought.
Our infradian clock doesn’t just control when we menstruate, but it controls our hormones that contribute to the progression and consistency of our menstrual cycle.
Our endocrine system is an extremely influential, yet intricate, network of glands that work together to secrete hormones regulating specific body functions.
The hypothalamus, an almond-sized brain structure, is the command center of the endocrine system. It receives a steady stream of data about hormone levels throughout the body.
Based on the data it receives, the hypothalamus fires off either a releasing hormone or an inhibiting hormone to the bean-sized pituitary gland situated right below it. The pituitary gland immediately activates, sending out hormones, or chemical messengers, to the other glands and organs in the endocrine system.
When communicating with various parts of the endocrine system, the pituitary gland uses different hormones to stimulate them. The pituitary gland sends:
- thyroid-stimulating hormone (TSH) → thyroid gland
- parathyroid hormone (PTH) → parathyroid
- adrenocorticotropic hormone (ACTH) → adrenals
- follicle-stimulating hormone (FSH) or luteinizing hormone (LH) → ovaries
After the respective hormone(s) have been sent, the target glands and organs decipher the message from the pituitary gland, and either ramp up, decrease, or pump the brakes on hormone production.
The Key Hormones
These hormones are the most prevalent throughout the menstrual cycle, and are referred to above and often when talking about menstruation. They include estrogen, progesterone, testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and insulin:
Estrogen is produced primarily in the ovaries but also in minimal amounts by the adrenal glands and fat cells. Estrogen essentially dictates the majority of your hormonal cycle and is a key indicator of hormonal health.
In regards to reproduction, estrogen is a key hormone for ovulation and is responsible for thickening the uterine lining as the uterus anticipates a pregnancy.
In addition, estrogen plays a key role in multiple other biological systems. It also protects an individual from dementia, bone density loss, heart disease, and high blood pressure.
Progesterone ramps up around ovulation; its main job is to control and maintain the uterine lining buildup as the uterus is anticipating a pregnancy.
If the egg isn’t fertilized, the progesterone levels fall, leading the uterine lining to be shed through menstruation.
Progesterone essentially counterbalances estrogen. In addition to initiating the second half of the menstrual cycle, progesterone promotes relaxation, improves sleep, and enhances moods.
Follicle-stimulating hormone (FSH)
FSH is released by the pituitary gland in the brain and stimulates ovarian follicles to mature. The levels of FSH, LH, and estrogen, increase until ovulation and because the follicles grow steadily under the influence of FSH, your estrogen level also rises.
Therefore, FSH imbalances can lead to infertility due to lack of follicle maturation and lack of other hormones that prepare the uterus for a fertilized egg and protect the woman throughout pregnancy.
Luteinizing hormone (LH)
LH is released by the pituitary gland in the brain at ovulation and triggers the release of a mature egg from an ovarian follicle and is also responsible for the production of estrogen in the ovaries.
After ovulation, the increase in LH helps the remaining follicle to transform into the corpus luteum. The corpus luteum then continues to produce estrogen and progesterone.
Abnormal LH issues are associated with fertility issues and PCOS. With high levels of LH, the hormone can trigger ovulation, but the follicle does not burst. As a result, the egg cannot enter the fallopian tube.
When consuming carbohydrates, the body breaks down the molecules into glucose, a monosaccharide. The pancreas secretes the hormone insulin as a response to the glucose in the bloodstream.
Insulin guides glucose into the body’s cells so that it can be used for energy, keeping blood sugar levels balanced. When insulin levels are thrown off, it can lead to blood sugar imbalances, resulting in menstrual irregularities and reduced fertility.
Cortisol is the body’s main stress hormone whose release is regulated by the body’s hypothalamic-pituitary-adrenal (HPA) axis. Cortisol levels are often the highest during the follicular phase.
While small amounts of cortisol can be beneficial, chronically high levels of cortisol can disrupt ovulation, decrease progesterone levels, and cause fertility problems, among a multitude of other health conditions whether related or unrelated to the reproductive system.
Taking Advantage of Your Cycle…..And Your Time
While the menstrual cycle is a collection of hormonal and biological processes coming together to create life within one’s body, it has an external effect as well.
In different phases of our cycle, certain traits are dominant, influencing our behavior and cognitive function and making us stronger in certain pursuits.
Follicular: The follicular phase is a time of beginning, a fresh start. This is the time for creativity and planning.
Ovulatory: This period is a time where we are at our most social and communicative. This is the time to maximize communicative and collaborative efforts.
Luteal: The luteal phase is a time of completion when one is naturally inclined to take initiative; finishing projects, accomplishing tasks, and beginning to turn attention to yourself towards the end of the phase.
Menstruation: This is an ideal time for reflection and looking inwards, analyzing your progress, and following your intuition.
Follicular (7–10 days): Creativity and Planning
As estrogen rises during this phase, the brain’s working memory capacity is enhanced. Specifically, the ability to handle complex processing tasks. Allocate your time towards mentally challenging assignments as your brain is naturally more inclined to solve problems strategize and plan.
In addition, hormonal levels during this phase spark creativity and enthusiasm. This is an ideal time to leverage your energy to take on exciting and challenging tasks and have brainstorming sessions.
Ovulatory (3–4 days): Communication and Collaboration
The rising estrogen during this phase increases synaptic connections, which can boost mental sharpness, creativity, and communication skills. This time can be leveraged by planning important conversations and communicating with others, as you can convey your opinions clearly and effectively.
In addition, your physical energy is at one of its highest points during the ovulatory phase. This energy can be utilized by taking on more taxing activities and a wider range of endeavors.
Luteal (10–14 days): Completion and Detail
As the corpus luteum is absorbed and progesterone rises, your energy begins to turn inward to focus on detail-oriented tasks. More often, you'll be drawn to notice more details and take on responsibilities that are more technical.
In addition, you’ll have a natural desire to wrap up projects and bring things to completion. As your energy expenditure lowers, it's important to focus on finishing important tasks rather than exhausting yourself with a large variety of activities.
Menstrual (3–7 days): Analysis and Reflection
Analysis and reflection are the dominant desires during this phase, as communication between both hemispheres of the brain is strongest during this time.
During this introspective period, take advantage of your time to check in with all aspects of your life, and your role within them. Understand what factors are causing you to feel uncertain, confused, or stressed about in your work, personal, or social life and evaluate how you can act on them.
A Better Way to Think About Time
After gaining a comprehensive insight into the detailed processes behind a once-a-month occurrence, it’s easy to see how much we’ve overlooked.
Now that we understand how intricate yet functional these processes are, we can use that knowledge to our advantage.
When you have two biological clocks, it’s easy to get overwhelmed or confused.
We have to rethink our relationship with time and how we use it.
It doesn't make sense to continue to trudge through a never-ending list of tasks to get done by the end of the day or sit in front of a laptop for hours on end while feeling as if nothing is being accomplished. Instead of just abiding by daily deadlines, it makes more sense to sync with our second clock to plan ahead; staying in a peak flow state as much as possible.
We have to manage our time in a cyclical fashion.
Hold brainstorming meetings on the days where your creative energy is the highest. Plan important meetings around the days when your communication skills are pronounced. And tackle detail-oriented and intricate tasks when you know that you’ll be more focused.
By being attentive to energy and mood fluctuations on a daily basis, you can draw awareness to the times when you can either maximize your productivity or allow yourself time to rest. If you are aware that the days leading up to your period are usually painful, uncomfortable, and filled with distraction, you can plan to allocate your most important tasks for the week before.
It can be scary to do this when society conditions us to believe that we can’t go to sleep until we have checked off every box on our to-do list.
We are conditioned to do continue working; do more, even more, and then some.
But with more introspection and awareness, and less stress, and strict adherence, we can actually accomplish more. I can name countless times that I have spent 6 hours on a 2-hour assignment or have hosted important meetings as I was trying to fight debilitating cramps.
It isn’t that avoiding the task at hand altogether is the best approach. Rather doing it efficiently is better than doing it inefficiently.
However, this process takes time. If you have a sporadic cycle, hormonal imbalances, or have never tracked your cycle, you can’t expect to get it right. It can take at least several months to track patterns and figure out the best approach.
You also can’t expect to micro-manage your life around your cycle. Your period is your period, and ultimately, we all have lives that extend beyond our reproductive processes. But even bringing awareness as to your energy levels throughout the month, when your PMS begins, or even certain times that you are more nauseous, irritable, emotional can have a profound impact on your life.
As I began to track my cycle, my symptoms, and details that I had previously been oblivious to, I realized how I was approaching my day-to-day life all wrong.
While plenty of problems I faced were still ambiguous or beyond my control, I realized how quickly my mindset, productivity, and mood changed in the second half of my cycle. I noticed that I was a lot more enthusiastic and focused soon after my period ended, but was much more irritable, would get distracted, and have headaches nearing the menstrual phase.
Gaining these insights provided me with an immense amount of value. Since I have adopted these principles allowing me to easily track my cycle, I’ve been able to hack myself.
I am now more intentional about making significant progress at the start of the month, and schedule exciting activities and plan projects. I’ll act more spontaneously, whether it be exploring the outdoors or frantically writing my thoughts and turning them into articles as my ideas begin to flow.
Just the same, I’ll take more time to rest towards the end of the month. I allow myself to take more time to reflect, be introspective, and consume more knowledge rather than create it. I know to allow myself more time to read books and watch videos on fascinating concepts rather than pressure myself to finish off an article.
Tuning into your cycle opens up a completely new way of thinking. It allows you to achieve more of what you want while enjoying the process and conserving your energy for the right times.
The problem never was and never will be a lack of time.
It’s time to let go of old patterns and adopt a productivity paradigm that's backed by your biology.
Thank you very much for giving this a read! If you learned something from this article, please share it with your friends and family. Be sure to connect with me and/or message me on Linkedin or at email@example.com, and leave this article a clap 👏 if you enjoyed it!
Note: If you enjoyed this article, I would highly recommend the book In the Flo by Alisa Vitti. Many of the concepts in the article are derived from this book, and Alisa’s voice and insights are truly worth reading.
Infradian Rhythm: Your Guide to a Perfect Cycle | Flo Living
If you’re a person with female physiology, you have an infradian rhythm — and it plays a vitally important role in your…
Biology for Majors II
The ovarian cycle governs the preparation of endocrine tissues and release of eggs, while the menstrual cycle governs…
The menstrual cycle, explained
This article is also available in: português, español The menstrual cycle starts with the first day of the period and…
Reproductive cycles in females
The reproductive system in females consists of the ovaries, uterine tubes, uterus, vagina and external genitalia…
How Women Can Use Monthly Periods As A Productivity Tool
Female hormonal cycles have natural and predictable fluctuations that effect mood, energy and cognition. Our bodies…
Chronobiology: The Science of Time - Chronobiology.com
Most of us have very little knowledge about the human body's inner clock. However, a young science from Europe called…
Women's Hormones: The Main Culprits for Changes in Your Health?
Whether it's lower energy, weight gain, irritability, decreased sex drive or other symptoms, as many women approach 40…