Your hormones don't stay the same. They oscillate across a roughly 28-day cycle (though anywhere from 21–35 days is normal), and these oscillations affect your training performance, recovery, nutrition requirements, mood, and even sleep. Understanding your cycle is the most underrated component of female health optimisation.
This isn't about predicting your mood or managing PMS (though it helps with both). It's about aligning your training intensity and nutritional strategy with your actual physiology.
The phases, and what's happening
Menstruation (days 1–5 approximately)
Your period is technically the beginning of your cycle, driven by the withdrawal of both oestrogen and progesterone. Bleeding happens when the uterine lining sheds.
Hormonally, you're at your lowest point: oestrogen and progesterone both drop sharply. This is why many women feel low energy or mood dip at the start of their period.
What to do: Light training. This isn't the week to chase PRs. Your pain tolerance is lower, your glycogen stores deplete faster, and recovery is compromised. Walking, mobility work, and moderate-intensity training are appropriate. Eat adequately — don't restrict calories.
Follicular phase (days 1–13 approximately)
After menstruation ends, your pituitary gland starts releasing FSH (follicle-stimulating hormone), which tells your ovaries to grow follicles containing developing eggs. These follicles produce oestrogen, which rises steadily across this phase.
As oestrogen climbs, so does your energy, motivation, strength, and pain tolerance. Neurologically, you're more resilient to stress. Your metabolic rate is slightly lower (roughly 100–300 calories daily less than the luteal phase). Carbohydrate oxidation is more efficient, meaning you're naturally burning carbs effectively for fuel.
What to do: This is your training peak. High-intensity interval training, heavy strength work, and challenging conditioning all work beautifully now. Your CNS (central nervous system) is more responsive. Your mood is typically elevated and motivation high. You'll set PRs here if you're going to set them.
Nutritionally: You can do well on lower carbohydrate intake. Your body oxidises fat efficiently. Some women thrive on a lower-carb approach during follicular; others don't notice much difference. Protein intake should remain stable (1.6–2.0g per kg body weight).
Ovulation (day 14 approximately)
Your oestrogen peaks, which triggers a surge in LH (luteinising hormone). This surge causes the mature follicle to rupture and release an egg. Ovulation happens over roughly 24–48 hours.
This is when testosterone peaks (your ovaries produce a surge of it during ovulation). Combined with peak oestrogen, this is the highest-energy point of your cycle. Libido peaks. Strength and training performance peak. Some women report peak confidence and social ease around ovulation.
What to do: Train heavy. This is your absolute peak for strength and high-intensity work. Your pain threshold is highest. Your motivation and drive are at their best. If you're testing a one-rep max or running a tough conditioning block, do it now. Testosterone's contribution to motivation and drive makes this feel easy.
Nutritionally: No particular changes needed. Stay hydrated — some women retain fluid slightly around ovulation.
Luteal phase (days 15–28 approximately)
After ovulation, the empty follicle transforms into the corpus luteum, which produces progesterone. Progesterone rises across the early luteal phase and peaks in the mid-luteal phase (around day 21), then drops sharply into menstruation.
Oestrogen stays elevated but is lower than peak. Progesterone is the dominant hormone now.
Progesterone has several practical effects:
- It elevates your metabolic rate by 100–300 calories daily compared to follicular (McNulty KL et al., 2020, Sports Medicine)
- It suppresses dopamine and serotonin slightly, which can affect mood and motivation
- It impairs strength performance by roughly 5–10% compared to follicular peak
- It increases your carbohydrate requirements and your preference for carbohydrate (your body partitions carbs differently)
- It elevates core body temperature
- It supports sleep drive (progesterone is mildly sedating)
What to do: Early luteal (around day 15–20) is still quite good for training, though you'll notice a dip in peak power compared to ovulation. Strength is still good, just not quite peak. Later luteal (days 21–28) is where many women struggle. Energy dips. Motivation dips. Pain tolerance drops. Training performance falls.
This is where many women make a critical mistake: they push hard anyway, driving fatigue, mood disruption, and injury risk. Instead, this is your deload phase. Lower volume, lower intensity, but don't stop training. Strength work is still appropriate; it's the high-intensity or conditioning work that becomes counterproductive.
Nutritionally: Your calorie needs are higher (100–300 calories). Your body wants carbohydrate. This isn't weakness or poor discipline — this is physiology. Eat the carbs. Increase them by 30–50 grams daily. Protein stays consistent. Some women find that progesterone's appetite-elevating effect makes them feel hungrier; this is normal and you should eat.
What each hormone actually does
Oestrogen
- Supports bone density (works synergistically with mechanical loading from training)
- Drives cardiovascular adaptation and blood flow
- Supports collagen synthesis (why many women notice better skin during follicular)
- Drives sexual desire
- Supports mood and motivation (mild dopaminergic effect)
- Increases pain tolerance (through both neurological and inflammatory pathways)
Progesterone
- Supports sleep and relaxation (GABAergic effect)
- Regulates body temperature
- Supports the luteal phase of the uterine lining (necessary for a viable pregnancy)
- Increases metabolic rate
- Slightly suppresses dopamine and motivation
- Increases appetite and carbohydrate preference (a real physiological drive, not hunger in the traditional sense)
Testosterone
- Peaks around ovulation (alongside oestrogen)
- Drives libido and sexual desire
- Supports strength and power output
- Drives motivation and drive
Tracking your cycle
The most practical approach is dual tracking: record your period dates and note energy, mood, and training performance.
Apps: Clue and Natural Cycles are evidence-based. They don't predict based on "average cycle" — they learn your actual pattern. Free or low-cost versions exist.
BBT (basal body temperature): Your waking body temperature drops slightly just before ovulation, then rises post-ovulation by roughly 0.4–0.8°C. If you take your temperature first thing in the morning (before getting out of bed), you'll see this shift. It's useful for confirming you actually ovulated.
Cervical mucus: Changes in consistency across the cycle (dry → creamy → slippery egg-white → back to dry) correlate with hormone shifts and ovulation. It's free to track but requires learning to observe it.
OPK (ovulation predictor kits): Detect the LH surge. Useful if you want to know exactly when ovulation happens, particularly if you're trying to conceive.
For most women interested in training and nutrition optimisation, tracking your period start date and noting how you feel is sufficient. After three cycles, the pattern becomes obvious.
Why this matters
Your training performance, nutrition requirements, and even your capacity to manage stress genuinely shift across your cycle. This isn't weakness or unreliability — it's physiology. Women who train and eat according to their cycle report better energy, better training results, easier body composition management, and better mood. Women who ignore it often end up fighting their biology and attributing normal cyclical changes to problems that don't exist.
Optimising your cycle doesn't require obsession. It requires awareness: knowing when to push and when to back off, and adjusting your nutrition accordingly. That simple shift changes everything.
Seb covers hormone optimisation and evidence-based health for adults over 30. He writes for maleoptimal.co.uk and maintains a focus on clinical evidence, practical implementation, and what actually works.