Most training plans were designed for men. Not because of bias exactly — it's that most foundational sports science research was conducted on male subjects. A plan that doesn't account for your hormonal cycle treats you like a man with a slightly different body. The results are predictable: you feel good some weeks, terrible others, and blame fitness.
The good news is that once you understand what's happening hormonally across a cycle, the pattern becomes predictable — and trainable.
The short version
Your oestrogen and progesterone levels move in a regular pattern across your cycle. These hormones affect energy availability, strength, endurance capacity, injury risk, and recovery rate. In the follicular phase, rising oestrogen supports performance. In the luteal phase, rising progesterone raises your resting heart rate, body temperature, and perceived effort — making the same session feel harder than it did two weeks ago.
This isn't weakness. It's physiology. Working with it is more effective than ignoring it.
Phase 1: Menstrual (days 1–5 approximately)
Oestrogen and progesterone are at their lowest. Energy may be reduced. Prostaglandins responsible for cramps can affect how you feel on runs.
What the research shows: There's no performance impairment from light exercise during menstruation for most women — the issue is individual. Some women run their best in the early days of their period. Others feel terrible. Both are normal.
How to train: Listen to your body here more than any other phase. If you feel good, train. If you feel depleted, this is the most legitimate recovery period in your cycle. Easy aerobic work, walking, and mobility are all appropriate. Don't force hard efforts.
Nutrition note: Iron losses during menstruation are real. If you're running significantly during your period, prioritise iron-rich foods and make sure you're not in a calorie deficit.
Phase 2: Follicular (days 6–13 approximately)
Rising oestrogen is the defining feature of this phase. Oestrogen supports muscle protein synthesis, improves insulin sensitivity, enhances mood, and reduces perceived effort. This is the phase where most women feel their best — and the data supports it.
What the research shows: Strength and power output are higher in the follicular phase. Pain tolerance is also higher, likely mediated by oestrogen's effect on the central nervous system. Recovery is faster.
How to train: This is your performance window. Schedule hard sessions, speed work, races, and strength training here. The body is primed for high-intensity work and will adapt more readily to training load. If there's a week to push, this is it.
Nutrition note: Carbohydrate metabolism is more efficient in the follicular phase. Your body uses glycogen well — this supports high-intensity work.
Phase 3: Ovulatory (days 14–16 approximately)
Oestrogen peaks just before ovulation, then drops sharply. LH surges and triggers the release of the egg. This is a short phase — often 2–3 days.
What the research shows: Peak oestrogen coincides with peak strength and coordination in many studies. Reaction time improves. This is often the best single moment in the cycle for performance.
How to train: Schedule your most demanding race or test effort here if you can. The caveat: joint laxity also peaks around ovulation. Injury risk, particularly ACL injury, is higher in this window. Warm up thoroughly and don't skip stability work.
Phase 4: Luteal (days 17–28 approximately)
Progesterone rises and dominates. This is the phase that causes the most confusion for female runners because training suddenly feels harder — and it is.
Progesterone raises your resting core temperature by 0.3–0.5 degrees Celsius. It raises your resting heart rate by 2–10 beats per minute. It increases your ventilatory threshold — meaning you breathe harder at the same effort. And it shifts your body toward fat burning and away from carbohydrate, which matters for high-intensity efforts.
The result: a run that felt like Zone 2 three weeks ago now registers as Zone 3. Your pace is slower. Your heart rate is higher. Everything feels heavier.
What the research shows: Perceived exertion is genuinely higher in the luteal phase at the same absolute workload. This is not in your head. Studies comparing RPE across cycle phases consistently find higher ratings in the late luteal phase.
How to train: Adjust your targets. Run by effort or heart rate zone, not pace. What was a 5:30/km easy run may need to become 5:50/km to stay in the same zone. The adaptation from the session is what matters — chasing pace in the luteal phase leads to overreaching.
Nutrition note: Your calorie needs are slightly higher in the luteal phase — research suggests 100–300 kcal/day above baseline. Protein intake is more important here, as progesterone drives protein catabolism.
How to actually use this
You don't need to overhaul your training programme. The application is mostly about adjusting expectations and scheduling.
- Track your cycle. You cannot work with something you aren't measuring. A basic period tracking app gives you enough data to know which phase you're in on any given day.
- Mark hard sessions in the follicular phase. If you have the flexibility to pick which week you run a hard tempo or race, pick the follicular phase.
- Run by effort in the luteal phase. Switch from pace targets to heart rate or RPE targets in the two weeks before your period. Your fitness hasn't changed. Your physiology has.
- Don't apologise for recovery in the menstrual phase. The week of your period is the most legitimate rest period in your cycle. Use it.
- Build cycle awareness over time. After two or three months of tracking alongside training notes, you'll start to see your own pattern — because individual variation is real.
Start tracking today
Flo Health is the most widely used women's health app for cycle tracking — 350 million users, detailed analytics for athletes, and a free tier that gives you everything you need to get started. The premium tier adds AI health insights and more detailed cycle predictions.
Track your cycle with Flo → (affiliate link)
A note on hormonal contraception
If you're on hormonal contraception, your cycle does not follow the same pattern described above. Combined oral contraceptives suppress ovulation and flatten hormonal variation — you won't have the same follicular high or the luteal shift. Some research suggests slightly blunted performance variation as a result, though the data here is still developing.
If you're on hormonal contraception and want to understand how it affects your training, a consultation with a sports medicine doctor or an endocrinologist with an interest in female athlete health is the best starting point.