Does the Menstrual Cycle Change How You Should Train?

Should women and other people who menstruate plan training around the phases of the menstrual cycle? Here is what the best evidence says about cycle phase and performance, why the research is hard to trust, and how to find out what your own pattern looks like.

Short answer

On average, the menstrual cycle appears to change exercise performance very little. The largest systematic review found trivial differences between phases, low-quality evidence and large variation between studies. Individual experience still varies, so symptoms and your own training notes matter more than a generic phase-by-phase plan.

Key facts

A 2020 systematic review and meta-analysis in Sports Medicine (McNulty and colleagues) pooled 78 studies with 1,193 participants and found performance was trivially lower in the early follicular phase than in other phases.
The same review rated the overall quality of evidence as low, and concluded that general guidelines cannot be formed and that a personalised approach is needed.
A 2021 working guide in Sports Medicine (Elliott-Sale and colleagues) says the hormonal profile in studies is often implied rather than confirmed, which makes results hard to compare.
Only 8% of the studies in the McNulty review were rated high quality, and 35% gave no information on how cycle phase was verified.
The NHS lists very heavy bleeding, severe pain and missed or stopped periods (overexercising is one possible cause) as reasons to talk to a GP.

In this article

Does the menstrual cycle affect exercise performance?
What did the largest review find, and how good was the evidence?
Why is research on cycle phases so hard to trust?
If the average effect is trivial, why do symptoms still matter?
How can you track your own pattern across cycles?
When should changes in your cycle or training prompt a clinician visit?
Frequently asked questions
Final thoughts
Sources and further reading

Does the menstrual cycle affect exercise performance?

The menstrual cycle may affect exercise performance slightly on average, but the best available evidence shows only trivial differences between phases, with big differences between individuals. Hormones such as oestrogen and progesterone do rise and fall across a cycle, so a performance effect is plausible, yet the data do not support one fixed rule for everyone.

How long and how regular a cycle is also varies from person to person, as covered in how regular is a regular cycle.

Who the research covers

Most studies recruit women with regular cycles and no hormonal contraception, so findings may not apply to everyone who menstruates.

What did the largest review find, and how good was the evidence?

The largest review found trivial performance differences across the menstrual cycle and rated the evidence as low quality overall. McNulty and colleagues pooled 78 studies with 1,193 participants and concluded that general guidelines could not be formed, recommending that each person is guided by their own response instead.

The numbers the authors reported

The 2020 systematic review and meta-analysis in Sports Medicine compared exercise performance in the early follicular phase (the first days of bleeding) with all other phases. In the pairwise analysis of 51 studies, performance in the early follicular phase was trivially lower, with an effect size of -0.06 and a credible interval of -0.16 to 0.04, which includes no difference at all.

A network analysis of 73 studies found the largest difference between the early and late follicular phases (effect size -0.14), which the authors also called trivial.

The stated quality of the evidence

The authors rated the overall quality of evidence as low. Of the included studies, 8% were high quality, 24% moderate, 42% low and 26% very low. They cited the trivial effect size, large variation between studies and poor study quality as reasons general guidance was not justified.

In plain terms, the effect on average is small, the evidence is weak, and the same phase can feel different from one person to the next.

Myth vs fact

Myth: Research has shown which phase of the cycle is best for hard training, so you should schedule workouts by phase.

Fact: The largest review found only trivial differences, low-quality evidence and large variation, and its authors advised a personalised approach rather than general phase-based guidelines.

Four women standing together on a tree-lined street in autumn

Why is research on cycle phases so hard to trust?

Research on cycle phases is hard to trust mainly because studies are small, use different methods and often assume hormone levels instead of measuring them. Elliott-Sale and colleagues, in a 2021 working guide for sport and exercise science, argue that this weakens comparisons between studies and limits how far results can be applied.

How studies identify the phases

Elliott-Sale and colleagues note that the hormonal profile of participants is often implied rather than confirmed. They recommend tracking cycles for at least two months before testing, using urinary ovulation kits to detect the mid-cycle luteinising hormone surge, and confirming hormone levels with blood analysis.

In the McNulty review, 10% of studies used calendar counting only, 31% combined methods including ovulation kits, and 45% combined methods without them. About 59% verified phases afterwards with serum hormones, while 35% gave no information on verification.

If the average effect is trivial, why do symptoms still matter?

Symptoms still matter because an average across many people can hide large differences between individuals, and how you feel affects how well you can train. Cramps, fatigue, headaches, low mood or disturbed sleep around a period are real experiences, even if cycle phase does not change measured performance much on average.

The McNulty authors recommended an approach based on each individual's response. The NHS describes premenstrual syndrome (mood swings, headaches, bloating) and says exercise may help with period pain.

What this means in practice

If you feel strong on day two of your period, there is no evidence you should hold back. If you feel flat and sore, easing off is a reasonable personal choice. Recovery is another variable, covered in how many rest days you actually need.

Luna Ring

Put your own notes next to your own data across several cycles

A ring cannot tell you which phase of your cycle you are in, but Luna Ring records sleep stages, heart rate, HRV, SpO2 and body temperature trends each night, with no subscription required. It is worn on a finger, so you can place your own training and symptom notes next to your own trends over several cycles and see what, if anything, repeats for you.

Explore Luna Ring ↗

How can you track your own pattern across cycles?

You can track your own pattern by keeping a short daily log of training, symptoms and energy for at least three cycles, then looking for anything that repeats. One cycle is rarely enough, because stress, illness, sleep and travel can all change how a given week feels, and a pattern should show up more than once.

The NHS recommends a symptom diary before a GP visit, so a log is useful either way. Keep it simple enough to maintain.

A training and symptom log

Each day, note the day of your cycle (counting the first day of bleeding as day 1), what you trained, how hard it felt, symptoms and a score for energy. The table shows what a filled-in log might look like.

Training and symptom log (illustrative example, not real data)
Cycle day	Training	Effort (1 to 10)	Symptoms	Energy (1 to 5)
2	30 minute walk	3	Cramps, tired	2
9	Strength session	7	None	4
16	5 km run	6	Slept badly	3
24	Strength session	7	Bloating, low mood	2

Try this: 7-day experiment

Pick any seven days and write down your cycle day (or note that your cycle is irregular).
Each evening, record what you trained, how hard it felt from 1 to 10, and any symptoms.
Each morning, rate your energy from 1 to 5 and note how you slept.
If you use a tracker, jot down its sleep, resting heart rate and HRV trends beside your notes, as context, not proof.
After seven days, ask whether your effort and energy ratings moved together. Then decide whether to keep logging for the full three-cycle plan below.

A 3-cycle self-tracking plan

3-cycle self-tracking plan
Cycle	What to do	What to look for
Cycle 1	Log cycle day, training, effort, symptoms and energy. Change nothing about your training.	Any weeks where energy or effort ratings look different
Cycle 2	Keep logging. Add sleep and morning trend notes if you track them.	Whether the same weeks look different again
Cycle 3	Keep logging. If a pattern repeated, try a small adjustment, such as easing one session.	Whether the adjustment feels better, worse or no different

If nothing repeats, that is a useful result too: it fits the review's finding that the average effect is small.

Red dots forming a stream against a blue background

When should changes in your cycle or training prompt a clinician visit?

Very heavy bleeding, severe pain, or periods that become irregular or stop while you train hard are reasons to speak to a GP or other clinician rather than adjust training alone. The NHS lists these among its period problems, and a log of your cycle and training gives a clinician useful information.

Heavy bleeding and pain

The NHS says you may have heavy periods if you need to change your pad or tampon every 1 to 2 hours, pass clots larger than about 2.5 cm, bleed for more than 7 days or soak through clothes or bedding. It advises seeing a GP if heavy bleeding affects your everyday life, has gone on for some time, comes with severe pain, or happens between periods or after sex.

For painful periods, the NHS says exercise and over-the-counter painkillers may help, and advises seeing a GP if the pain affects your daily life.

Missed periods and low energy availability

The NHS lists pregnancy, stress, sudden weight loss, overexercising and menopause among the causes of missed or stopped periods, and advises seeing a GP if you are concerned. Elliott-Sale and colleagues define secondary amenorrhoea as the absence of three or more consecutive periods.

The 2023 International Olympic Committee consensus statement on Relative Energy Deficiency in Sport (REDs), in the British Journal of Sports Medicine, describes a syndrome in which energy intake is inadequate relative to the energy spent on exercise, and introduces a clinical assessment tool. If you train hard and your periods stop or become irregular, ask a clinician rather than self-diagnosing.

Who should take extra care

If you are pregnant, using hormonal contraception, taking medication or living with a medical condition, speak to a clinician before changing how you train. Hormonal contraception changes the picture, as discussed in does hormonal birth control change recovery, heart rate and HRV.

Frequently asked questions

Is it better to lift heavy at certain times of the menstrual cycle?

No phase has been proven best. The largest review found only trivial differences between phases and rated the evidence as low quality, so it advised a personalised approach. If you feel strong at a particular point in your cycle, use that. If you feel flat, ease off without worrying.

Should I train less on my period?

Not necessarily. The review found performance only trivially lower in the early follicular phase, which is when bleeding usually occurs, on average. The NHS notes that exercise may help period pain. How you feel on the day is a better guide than the calendar, so adjust if you need to.

Can I use a phone app to plan workouts by cycle phase?

An app can help you log symptoms, but a phase-based plan rests on weak evidence. Elliott-Sale and colleagues note that phases are often assumed rather than confirmed, and a calendar cannot confirm ovulation. Treat app predictions as guesses and keep your own notes on how training actually feels.

Is it normal for periods to stop when training hard?

It is not something to ignore. The NHS lists overexercising among possible causes of missed or stopped periods and advises seeing a GP if you are concerned. Stopped periods with heavy training can be linked with low energy availability, so ask a clinician for advice rather than assuming it is normal.

How many cycles should I track before deciding anything?

Three cycles is a sensible starting point, because one cycle can be thrown off by stress, illness, travel or poor sleep. Look for something that repeats, not a single bad week. If no pattern appears, that is a valid result, and you can simply train by how you feel.

Final thoughts

Here is the short recap.

The largest review found trivial average differences in performance across the cycle, low-quality evidence and large individual variation.
Research on phases is limited by small studies and by phases that are often assumed rather than confirmed.
Your own symptoms and training notes across several cycles are the best guide, and heavy bleeding, severe pain or stopped periods need a clinician.

Your turn: Have you noticed a pattern between your cycle and how your training feels, or does it vary from month to month? Tell us in the comments.