Welcome back to Cycle Literacy, where we learn to read the language of our bodies.
There’s a moment many of us know far too well. It’s a week before your period, you slept eight hours, and you still wake up feeling like you’re moving through honey. Your workout feels heavier, your patience is thinner, and a little voice says: what is wrong with you? Last week you could do all of this.
Nothing is wrong with you. You’re simply not the same woman every week of the month, and you were never meant to be. Today I want to show you why your need for rest changes across your cycle, and why honouring it is not weakness but biology.
A 24-hour clock in a 28-day body
Men’s hormones follow a roughly 24-hour rhythm: testosterone is higher in the morning and lower in the evening, and that pattern repeats day after day. Women have that daily rhythm too, but on top of it we have a second, monthly rhythm: the menstrual cycle, in which oestrogen and progesterone rise and fall over roughly 21 to 35 days.
Most of our world, from school timetables to office hours to training plans, was built around the 24-hour rhythm. So when we feel different from one week to the next, we assume we’re failing a standard that was never designed with our bodies in mind.
Let’s walk through the four phases and what each one asks of you when it comes to rest.
Menstruation: your inner winter
When your period starts, oestrogen and progesterone are both at their lowest. At the same time, your uterus releases prostaglandins, compounds that help the lining shed but also drive cramps and a general feeling of inflammation. Add the blood loss itself, and it makes complete sense that many women feel tired, inward and low on energy during these days.
This is the phase where rest is most obviously needed, and it’s also the one we’re most often told to push through. Your rest here can look like: earlier nights, warm meals, gentle movement such as walking or stretching instead of intense training, and fewer social plans where possible. Think of it as a short winter: a time to slow down, take stock and let things go.
Follicular phase: your inner spring
After your period, oestrogen starts to rise. Many women notice their energy, mood, motivation and social drive climbing with it. This is often when we feel most like the “productive” version of ourselves.
Rest still matters here, but you’ll probably need less of it to feel good. This is a lovely time to start new projects, try a new workout or plan your month, while still protecting your sleep so you don’t spend this energy faster than you can replenish it.
Ovulation: your inner summer
Around ovulation, oestrogen peaks and there’s a short surge of luteinising hormone, with a small rise in testosterone. For many women this is the phase of peak confidence, connection and outward energy.
The risk here is subtle: because you feel so good, it’s easy to say yes to everything and fill your calendar for the weeks ahead, forgetting that a different version of you will have to live those weeks. A gentle practice for this phase: before you commit to something, check your cycle and ask, will I want this when I’m in my autumn?
Luteal phase: your inner autumn
This is where our theme really comes alive. After ovulation, the empty follicle becomes the corpus luteum and starts producing progesterone. Progesterone does several things that directly affect how rested you feel:
It raises your core body temperature by roughly 0.3 to 0.5°C. That’s exactly why temperature tracking can confirm ovulation, but a warmer body can also make it harder to fall and stay asleep, especially in the days before your period.
It nudges your metabolism up slightly. Your body is doing more behind the scenes, preparing the uterine lining for a possible pregnancy. This is one reason appetite often increases in this phase.
It has a calming, sedating side. A substance your body makes from progesterone, allopregnanolone, acts on the same calming GABA receptors in the brain that are involved in relaxation and sleep. Many women feel this as a drowsier, more inward state.
Then, in the last days before your period, progesterone and oestrogen both drop. For some women that drop brings poorer sleep, mood shifts, irritability or anxiety, which we know as PMS. So the luteal phase often asks for more rest, more nourishment and more gentleness at the same time that our bodies are working harder.
This is your inner autumn: a time to finish rather than start, to edit rather than create from scratch, to turn inward and to prepare.
Stress, cortisol and your cycle
There’s one more piece of the puzzle that shows why rest is not optional. Your stress-response system and your reproductive system are closely connected in the brain, in an area called the hypothalamus. When your body perceives chronic stress, whether that’s too little sleep, too much training, under-eating or constant mental pressure, it can quite literally deprioritise reproduction.
This can show up as later ovulation, a shorter luteal phase, more intense PMS, irregular cycles or, in more extreme cases, a missing period altogether. Your body is not betraying you when this happens. It’s protecting you, deciding that this is not a safe moment to invest in reproduction. Rest is one of the most direct ways to tell your body that it is safe again.
What the research does and doesn’t say
I always want to be honest with you here. Research on how the cycle affects energy and performance is still young, and women have long been left out of clinical and sports studies. When scientists average results across many women, the differences between phases are often smaller than the stories online make them sound, and individual women differ a lot from one another.
That’s exactly why I believe in cycle literacy rather than strict cycle rules. Your body is not a textbook. The four seasons are a map, but you’re the one who knows the landscape.
Your practice this week
Note where you are in your cycle today. Day 1 is the first day of full bleeding.
Rate your energy and sleep from 1 to 5 every evening this week. Just two numbers, nothing more.
Look for your own pattern. After two or three cycles, you’ll start to see which days you truly need more rest. That’s information no app, book or coach can give you better than your own body can.
Plan with your seasons. Put demanding tasks in your spring and summer when you can, and protect your autumn and winter with more space.
You’re not lazy. You’re not inconsistent. You’re cyclical, and that’s not a flaw to fix. It’s a language to learn.
With love, Ninalotte
Which phase do you find the hardest to rest in? Tell me in the comments, I read every one.
This article is for education and isn’t a substitute for personal medical advice. If your sleep, mood or cycle changes are significantly affecting your life, please talk to your doctor or gynaecologist.