It’s time to meet your infradian rhythm.
If you’re a person with female physiology, you have an infradian rhythm — and it plays a vitally important role in your health and wellbeing.
The infradian rhythm is one of your body’s two internal time keepers. (The other timekeeper is the circadian rhythm.) The infradian rhythm influences six different systems of the body: brain, metabolism, immune system, microbiome, the stress response system, and the reproductive system.
Why is it important to learn about your infradian rhythm?
Just look at the past 10 years: There’s been an explosion in online wellness content — new diet protocols, new fitness programs, new ‘extreme’ biohacks like cryotherapy and infrared saunas — but women’s hormone and autoimmune conditions have jumped nearly 50-percent in that same time period. That’s because most medical research ignores the unique needs of people with female physiology.
Medicine has ignored the infradian rhythm, how it operates, and what it means for women and all people with female physiology.
My new book In the Flo is all about the infradian rhythm and how learning to live in line with our bodies’ ‘second timekeeper’ can help erase period problems, balance hormones, and help us live without symptoms like acne, bloating, cramps, missing or irregular periods, and heavy periods.
Here’s what you need to know about your infradian rhythm and how to eat, exercise, work, and live in ways that support it.
What is the Infradian Rhythm?
The infradian rhythm is one of two internal timekeepers experienced by people with female biochemistry. It is a 28-day cycle that regulates the menstrual cycle. The infradian rhythm powerfully affects six different systems of the body:
- Immune system
- Stress response system
- Reproductive system
The infradian rhythm is also referred to as the body’s ‘second clock.’ The body’s other innate timekeeper is the 24-hour circadian rhythm, which is experienced by both men and women. The infradian rhythm is only experienced by people with female physiology.
How Does the Infradian Rhythm Influence Your Body and Brain?
Did you know that:
- The infradian rhythm creates a 25% change in your brain chemistry over the course of the month?
- Your metabolism speeds up and slows down predictably across the month and that you need to change what you eat and the intensity of your workouts each week in order to optimize your metabolism?
- Your cortisol levels are higher in one part of your infradian cycle, so pushing yourself through an intense workout bumps up cortisol levels even further, adding to your stress and inflammation, disrupting your hormones, and making you feel anxious and unfocused?
- People with female biochemistry need more sleep than men because we have a more complex brain and it needs 20 minutes longer to clean itself and reset for the cognitive day?
- People with female physiology tend to need less in the way of extreme self-care practices because we have more efficient biology.
As this list shows, your body and brain change significantly throughout the course of a month. Specifically, we move through four distinct phases within the course of 28-days. They are:
- Phase 1: Follicular (the 7 to 10 days after your period)
- Phase 2: Ovulatory (the to 4 days in the middle of your cycle)
- Phase 3: Luteal (the 10 to 14 days between ovulation and your period)
- Phase 4: Menstrual (the 3 to 7 days of your period)
During each of these four phases, you experience normal hormonal fluctuations that influence your body temperature, skin elasticity, sleep cycle, energy, emotions, and cognitive function.
What’s more, your 28-day cycle (infradian rhythm) works in close concert with your 24-hour cycle: a dysregulated infradian rhythm will mess with your circadian cycle—and a wonky circadian cycle will negatively influence your infradian cycle. In this way, using phase-based self-care not only supports your month-long hormone cycle but also your 24-hour sleep-wake cycle. This makes practicing The Cycle Syncing Method™ even more powerful in promoting hormone health and overall health.
Why Most Wellness Protocols Don’t Work For the Infradian Rhythm
People with female physiology benefit when they eat, exercise, and work in ways that support their infradian rhythm, as opposed to following diet, fitness, and work trends that disrupt it. It’s precisely because so many women try to follow the ‘same-thing-everyday’ plans that work for male physiology that 50% of women are suffering with hormonal imbalances, while men don’t suffer them at the same rate.
You’ve probably heard of the circadian clock, or the 24-hour biological rhythm that is inherent to all of us, men and women, old and young. This internal timekeeper directs many of the body’s internal processes, from when we get our get our deepest sleep (around 2:00am) and when we’re at our most alert (around 10:00am) to when we’re the most coordinated (2:30pm) and when we have the fastest reaction time (3:30pm). The circadian clock also helps regulate our body temperature and metabolism. Men's testosterone production is organized around the circadian rhythm (and so is the vast majority of fitness and nutrition research and advice; more on that below)
But people who menstruate also follow the infradian rhythm, which is linked to the menstrual cycle. And when you understand your infradian rhythm and how it informs your unique female biochemistry, you can become calmer, happier, and healthier, as well as more productive at work and more satisfied in your relationships. Your hormones will stay balanced and you can live symptom-free.
What does that look like in practice?
You can, for example, schedule important meetings at work during the phase of your cycle when you’re primed for communication. Or you can plan your workouts around your shifting biochemistry throughout each infradian cycle, doing high-intensity workouts when your body will make the most of them—and avoiding them during phases when a heart-pounding workout will do your body more harm than good. For optimal health and performance, you need to learn as much as you can about your second clock and then nurture your unique female biochemistry with phase-specific self care.
In the Flo is all about unlocking the secrets of our “second clock” and leveraging the power of phase-based self-care not only to erase period problems, but to live healthier, happier, more productive, and more fulfilling lives. In the Flo details everything you need to know about living in sync with your cycle.
In this post, I’m going to give you a sneak peek at your infradian rhythm, explain why no one else is talking about it, outline why the medical establishment largely ignores it, and introduce you to The Cycle Syncing Method™, which is the revolutionary phase-based self-care practice I developed based on years of research and working with women all over the world to help them erase period problems, reverse hormone conditions like fibroids and PCOS, and live happier, healthier lives.
Why Doing the Same Exercise Routine Everyday Hurts the Infradian Rhythm
Our bodies and brains are different during each phase of our cycle, so our food, exercise, and self-care should be different each week, too.
If you’ve been living in a ‘same-thing-everyday’ way, you’re not alone. There is a widespread cultural belief that we are supposed to repeat the same rituals every 24 hours — have the same morning routine, for example, or exercise the same way each week. But this insistence on doing the same thing day-in and day-out caters to the male hormonal biological rhythm. Men follow the same predictable pattern everyday: the 24-hour circadian clock and only the 24-hour circadian clock.
People with female biochemistry having shifting hormones and shifting needs all month long. This manifests in a lot of different ways, but you can get a good sense of what I mean if we look at one specific example. Take exercise. During your follicular and ovulatory phase, your metabolism is SLOWER and resting cortisol levels are LOWER. As such, you need fewer calories during these two phases, and when you couple that lower caloric intake with cardio and HIIT workouts—30 minutes is sufficient, but you can go longer if you are healthy—it creates a metabolic situation in which you use your glucose stores for energy, fat burning, and building more lean muscle without disrupting blood sugar or increasing cortisol, which would trigger inflammation and fat gain—the exact opposite of what you want to happen.
You don't have to avoid any specific workouts during this phase, but the ones that will net you the results are cardio and HIIT.
During the luteal and menstrual phase, your metabolism is FASTER and resting cortisol levels are HIGHER. So you’ll need MORE overall calories each day (around 250 extra calories) and when you eat carbs they must be complex carbs to keep blood sugar levels stable. If you don’t increase your calories during this time, it will interfere with hormone balance and trigger fat storage. What’s more, because your cortisol levels are higher, you need to limit workouts to 30 minutes only and stick to simple strength training, pilates, or yoga without a high intensity cardio component.
Why Don’t People Know About the Infradian Rhythm?
Historically, medical research has deprioritized women’s health issues and/or not included women in medical research.
Precisely because of our unique 28-day hormone cycle. When putting together clinical trials, many researchers have decided it is simply too complicated to include women as subjects because our monthly hormone cycle is too complicated. It has been perceived as too complex to control for all the hormonal shifts women go through every 28-days, so instead of trying to account for those fluctuations, researchers have just left women out and focused on men, whose predictable 24-hour circadian cycles do not vary from day to day.
Another reason? When women go to the doctor, women’s concerns about their health are often dismissed as psychological. Women are told that their symptoms are in their head, or that they are imagining their pain, or that they’re overly concerned about their physical well-being. Studies back-up this theory: one report found that almost half of those who went on to be diagnosed with an autoimmune condition (the majority of people who experience autoimmune conditions are women) were originally told that they were too worried about their health. This is all to say that when medical professionals have the chance to explore women’s symptoms in more detail and understand the root cause of their symptoms, they often don’t.
Medicine doesn’t know a lot about women’s health, explains author Maya Dusenbery in the book Doing Harm: The Truth About How Bad Medicine and Lazy Science Leave Women Dismissed, Misdiagnosed, and Sick, and it doesn’t pay serious attention to their symptoms. There is a gender bias in medicine and if you have experienced period problems like acne, bloating, cramps, heavy or irregular periods, missing periods, PMS or other hormone-related symptoms and not been helped by traditional interventions, you know this firsthand.
But you can break the cycle of symptoms, and look and feel your best, when you ditch the idea that you are supposed to live the same way everyday and start living in sync with your cycle.
The Cycle Syncing Method™ 101
Once I uncovered all of this about the infradian rhythm and our specific needs, it was clear that we needed a diet, fitness and lifestyle program that would help us support our biological rhythm. This is why I created The Cycle Syncing Method.™ Practicing The Cycle Syncing Method™ is easy. It starts with deepening your familiarity with your 28-day hormone cycle—something you can do with the MyFlo app—and then tailoring your food, movement, supplements, and lifestyle choices to your unique strengths, weaknesses, and needs during each phase of your cycle.
That might sound daunting. It’s not. Before long, you will develop an intuitive sense of how your body feels during each phase of your cycle and what it needs to maintain hormone balance. You will begin to naturally shift your food, movement, and schedule as your hormones fluctuate. With time, making phase-based self-care choices will be second nature.
What type of phase-based choices am I talking about? Here’s a closer look at the different ways The Cycle Synching Method™ is used in practice:
Food. Do you have certain cravings during different weeks of the month? Do you feel hungrier at different stages of your cycle? If so, you already have an embodied sense of your shifting needs each month. Practicing The Cycle Synching Method™ with food starts by choosing specific foods that will support optimal hormone balance in each phase. I go into more detail here, and I do a deep dive in my new book In the Flo, which is packed with biohacking advice and meal plans.
Supplements. Sometimes, even if you’re eating perfectly, supplements are necessary to deepen your phase-based self-care plan, erase your period problems, and feel your best. If you are deficient in any of the five essential micronutrients required for hormone health, you will never fully resolve symptoms like acne, bloating, PMS, cramps, menstrual migraines, missing or irregular periods, or cyclical fatigue and moodiness.
Exercise. Planning your workouts in sync with your cycle will allow you to achieve your fitness goals with less effort. It also makes your workouts easier because you are not trying to do a workout that is ill-matched for your hormones during a specific time. Using The Cycle Synching Method™ for exercise is a win-win.
Productivity. Let me be clear, and the research confirms - you as a woman, can do ANYTHING ANYTIME. The research also shows that as hormones stimulate the brain in different ways throughout the month, that you are more interested and more naturally at ease with certain tasks at different times of the month. The same is true of men of course, their brains are stimulated just over the course of one day and they do arrange their work to be optimally productive based on their hormonal patterns. So when we plan our schedules accordingly—for example, when we schedule important meetings or interviews when we are primed for communication—we may find even more success - and more importantly experience less overall stress on your body.
Sex Drive. Sixty percent of women are sexually unsatisfied because we don't understand how our infradian rhythm affects our sexual desire and changes our requirements for physical stimulation in each phase. Once you get the right key, the ignition will work every time and you don't ever have to think something's wrong with you again.
Relationship. Nurturing a healthy, balanced relationship takes work, and using your infradian rhythm to organize the activities you might want to do with your partner can be a helpful way to bring in a wider variety of experiences. From trying new things to going out with friends, to romantic date nights, to Netflix and chill nights at home — timing these according to your biological rhythm increases pleasure, positive connection, and decreases stress!
Motherhood. You can use your infradian rhythm to organize your approach to motherhood, too. With your cycle as your guide, you can plan to do the things that matter most to you as a parent at times of the month when your interest in those activities is highest and when you will naturally be your best at those things. By planning out your parent-child time in this way, you will prevent burnout, be less susceptible to the cult of perfectionism around motherhood, and create more quality time with your children.
Simply put, The Cycle Syncing Method™ can help you:
- Get more time back in your day to take care of yourself
- Stop dieting every day of your life and getting little or no results?
- Accomplish everything on your to-do list without feeling overwhelmed and burned out?
- Have a more satisfying relationship and sex life without the drama and frustration?
- Maximize the right workouts for your energy levels, so you have energy to spare?
- Spring out of bed in the morning and maintain your energy throughout the day?
My new book In the Flo will help you achieve all this — and more. If you’re ready to harness the power of your unique female biochemistry to look and feel your best, grab a copy of In the Flo and get to look, feel, and perform your best.
Baker FC and Driver HS. Circadian rhythms, sleep, and the menstrual cycle. Sleep Medicine. 2007;8(6):613–22. https://doi.org/10.1016/j.sleep.2006.09.011
Baron KG and Reid KJ. Circadian misalignment and health. International Review of Psychiatry 2014 Apr;26(2):139–54. https://doi.org/10.3109/09540261.2014.911149
Bellezza S, Paharia N, and Keinan A. Conspicuous consumption of time: When busyness and lack of leisure time become a status symbol. Journal of Consumer Research. 2017; 44(1):118–138. https://doi.org/10.1093/jcr/ucw076
Breus M. The Power of When: Discover Your Chronotype and the Best Time to Eat Lunch, Ask for a Raise, Have Sex, Write a Novel, Take Your Meds, and More. New York: Little, Brown, 2016.
Chang A-M, Aeschbach D, Duffy JF, et al. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. PNAS. 2015; 112(4)1232–37. https://doi.org/10.1073/pnas.1418490112
Csikszentmihalyi M. Flow. New York: Harper, 1990.
de Botton A. Status Anxiety. New York: Vintage Books, 2008.
Dietrich A. Neurocognitive mechanisms underlying the experience of flow. Consciousness
and Cognition. 2004;13:746–61. https://doi.org/10.1016/j.concog.2004.07.002
Etkin J, Evangelidis I, and Aaker J. Pressed for time? Goal conflict shapes how time is
perceived, spent, and valued. Journal of Marketing Research. 2015;52(3):394–406. https://
Maslow, A. Motivation and Personality, 3rd ed. New York: Longman, 1987.
National Institute of General Medicine Science. “Circadian Rhythms.” https://www
Nicolaides NC, Charmandari E, Chrousos GP, et al. Circadian endocrine rhythms: The
hypothalamic-pituitary-adrenal axis and its actions. Annals of the New York Academy of
Sciences. 2014;1318:71–80. https://doi.org/10.1111/nyas.12464
NobelPrize.org. “The 2017 Nobel Prize in Physiology or Medicine.” Press release, Oct. 2,
https://www.nobelprize.org/nobel_prizes/medicine/laureates/2017/press.html Saran S and Srikumar M. “AI has a Gender Problem. Here’s What to Do About It.” World Economic Forum, 2018. https://www.weforum.org/agenda/2018/04/ai-has-a-gender
Schmidt C and Bao Y. Chronobiological research for cognitive science: A multifaceted
view. PsyCH Journal. 2017;6(4)249–52. https://doi.org/10.1002/pchj.203
Schulte B. Overwhelmed: Work, Love, and Play When No One Has the Time. New York: Sarah Crichton Books, 2014.
Schwartz T and McCarthy C. “Manage Your Energy, Not Your Time.” Harvard Business Review. Oct. 2007. https://hbr.org/2007/10/manage-your-energy-not-your-time
Semaan J. “The Hungry Ghost and Always Wanting More.” Medium.com. Feb. 10, 2017. https://medium.com/@jessicasemaan/the-hungry-ghost-and-always-wanting-more -2bb397dbdc10
Sensi S, Pace Palitti V, and Guagnano MT. Chronobiology in endocrinology. Annali dell’Istituto Superiore di Sanita. 1993;29(4):613–31. https://www.ncbi.nlm.nih.gov /pubmed/7985925
Shechter A and Boivin DB. Sleep, hormones, and circadian rhythms throughout the menstrual cycle in healthy women and women with premenstrual dysphoric disorder. International Journal of Endocrinology. 2010;2010:259345. https://doi.org/10.1155/2010 /259345
Winget CM, DeRoshia CW, and Holley DC. Circadian rhythms and athletic performance. Medicine and Science in Sports Exercise. 1985;17(5):498–516. https://www.ncbi.nlm.nih .gov/pubmed/3906341