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Should you plan your training blocks around your cycle?

By Chris Ayers 6 min read

Cycle syncing is the idea that you should build your training program around your menstrual cycle: heavy blocks in the follicular phase, lighter work in the luteal phase, a pullback during your period. It is a tidy idea, and the app I built contains a version of it. So I think I owe you a fair look at the evidence on cycle syncing workouts, including the parts that argue against my own feature.

The case for

The best argument comes from a 2022 narrative review in Sports Medicine by Kissow and colleagues. They reviewed studies in which women did more of their resistance training in one phase than the other. Their conclusion: “studies indicate that resistance training conducted in the follicular phase … may be superior to luteal phase-based training in terms of enhancing muscle strength and mass.” Their proposed mechanism is that the hormones that shift across the cycle “regulate protein metabolism and recovery processes in skeletal muscle”.

The authors are careful about it. “May” and “possibly” are their words, and a narrative review summarizes studies rather than pooling their numbers, so it carries less weight than a meta-analysis.

The case against

Three pieces of evidence point the other way, and they are the heavier ones.

A 2020 meta-analysis in Sports Medicine by McNulty and colleagues pooled 51 of 78 studies and found performance “might be trivially reduced during the early follicular phase of the MC, compared to all other phases.” The quality of evidence was rated low. The authors wrote that “general guidelines on exercise performance across the MC cannot be formed” and recommended a personalised approach based on each woman’s own response.

A 2023 umbrella review in Frontiers in Sports and Active Living, which is a review of the reviews, went further. Colenso-Semple and colleagues “observed highly variable findings among the published reviews” and “a pattern of poor and inconsistent methodological practices in the literature”. A common problem was that studies did not verify which phase a woman was actually in. Their conclusion: “it is premature to conclude that short-term fluctuations in reproductive hormones appreciably influence acute exercise performance or longer-term strength or hypertrophic adaptations”. The title of the paper is blunter than the abstract. It says current evidence shows no influence of cycle phase on acute strength or on adaptations to training.

Then a 2026 study in Sports Medicine by Munteanu and colleagues did what the umbrella review asked for. Twenty-eight resistance-trained women trained through two supervised mesocycles, about eight weeks, on bench press and trap bar deadlift. Phases were checked with ovulation tests and blood hormones, not only counted from a calendar. Bar speed differed from expected by about 0.01 to 0.02 meters per second across phases. Motivation to train “was a strong predictor of training performance”, while readiness to perform was not. The authors wrote that “these findings support consistent resistance training across the menstrual cycle, without the need for phase-based adjustments”.

Weighing it

One narrative review says phase-based training may help. One meta-analysis finds trivial effects and low-quality evidence. One umbrella review finds the reviews too variable to conclude that hormone swings matter much. One well-controlled lifting study finds minimal phase effect and names motivation as a strong predictor.

If I were scoring it, the weight of evidence favors training consistently and letting your own days, not the calendar, decide when to push.

That does not make cycle syncing worthless. A lifter whose period reliably wrecks her first two days is not wrong to plan around it. But she is planning around her own pattern, which she learned by paying attention over several cycles. That is different from a rule handed down from a 28-day template that assumes everyone is the same.

What I built, and why it is a forecast you can overrule

Ferrabelle has a 7-day training forecast and, in Pro, training blocks that adapt to your readiness. The forecast starts from your predicted phases: often stronger in the first half of the cycle, lighter during your period and in the second half. Right next to it, the app says: “Research on cycle phases and strength is mixed, so treat it as a guide and go by how you feel.” That line is there on purpose.

The blocks adapt to your Fe Score, which is built from your sleep, stress and recovery as well as your phase, and which drifts toward your own logs the more you record. The forecast is a starting guess. Your log is the correction. If the forecast says a heavy day and your sleep says otherwise, the app does not argue with you.

I will be honest about the tension. I built a cycle-aware training feature, and the best-controlled study above found that motivation mattered more than phase. The reason I keep it is not that I think the research is wrong. It is that a forecast which starts from the population and then bends to you is a reasonable way to learn your own pattern, and a personalised approach is what the 2020 meta-analysis recommends. If after a few cycles your logs show that your phases do not matter much, the app has done its job. Lift heavy whenever you feel like it.

This is general information, not medical advice. Talk to your doctor about your own health.

Ferrabelle is in a closed test on Google Play right now. If you want to try it, you can join at ferrabelle.com/testers.

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