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Lifting through perimenopause

By Chris Ayers 5 min read

For many women in their forties, two things start to happen at once. Cycles get less predictable, and muscle gets harder to keep. Neither one is a reason to put the barbell down. The research, read carefully, says something closer to the opposite.

I am not a doctor and I am not a coach. What follows is what three studies and one health service actually found, with their caveats left in. Where I say what the app does, that is the only part I can speak to with authority.

Cycles change first

The NHS puts menopause usually between the ages of 45 and 55, and lists the start of menopause among the common reasons for periods to become irregular or go missing. The years before that point are when the pattern starts to loosen.

The Apple Women’s Health Study, published in npj Digital Medicine in 2023, measured how much. Across 165,668 cycles from 12,608 US participants, cycle variability was lowest at ages 35 to 39. At 45 to 49 it was about 45% higher than that low point. Over 50 it was 200% higher. Mean cycle length got shorter with age up to 50, then longer.

So if your cycles used to arrive like a train and now arrive like a bus, that is the published pattern for your age group, not a personal failing of your tracking.

It is also why Ferrabelle has a cycle tracking mode called “Perimenopause and irregular cycles.” In the app’s own words, it shows “Predictions as a wider range.” The engine is honest about long cycles on its accuracy page: on the public test dataset, cycles over 35 days predicted at about 2.8 days mean error against 1.79 days for the regular range. A wider range is the truthful answer, so that is what the mode shows.

Muscle drops, and activity helps hold it

A 2020 study in the Journal of Clinical Medicine followed 234 Finnish women aged 47 to 55 from perimenopause into early postmenopause. Over that window, lean body mass, leg lean mass and thigh muscle area all fell. The authors’ summary: “Menopausal transition was associated with loss of muscle mass at multiple anatomical levels, while physical activity was beneficial for the maintenance of skeletal muscle mass.”

Two things to keep straight about that result. First, the loss was measured at several levels of the body, not one lucky site. Second, it was a follow-up study, not a trial. More physical activity went with keeping more muscle, but the study design shows a link, not proof that activity caused the difference. The research card inside the app says the same thing, because I would rather under-claim.

Lifting still builds strength

The strength question has a small but direct answer. A 2023 trial in BMC Women’s Health enrolled 41 women with a mean age of 52, of whom 31 finished. The first 10 weeks were a control phase with no lifting. Then came 10 weeks of free-weight training, twice a week, at either a light or a moderate load. The women were grouped as pre-menopausal or post-menopausal by their hormone levels. The result: “Significant increases in 1-RM squat and bench press were observed in all groups.” Pre-menopausal and post-menopausal women both got stronger, at both loads. “No injuries occurred during the intervention.”

Muscle size was the harder part. Growth showed up only in the women who were still pre-menopausal. The authors suggest that post-menopausal women likely need more than the 6 to 8 sets per muscle per week the study used to see the same change. I am reporting what the study did and what its authors concluded, not telling you how many sets to do. Thirty-one people is a small trial, and ten weeks is a short one.

Put the two studies side by side and the picture is plain enough. Muscle drops across the transition. Lifting still raised squat and bench numbers at this age. Building size after menopause may take more volume than the study used, and the evidence on exactly how much is thin.

What this means for the log

If strength is still trainable and size is harder, then the numbers worth watching change a little. Your lifting log and its PRs tell you whether the strength side is working. Your Fe Score tells you, each morning, where your phase and your recovery sit, which matters more when the phase itself is less predictable. And the research notes inside the app, under Perimenopause, include the two muscle studies above, with a “What this cannot tell you” list attached, so you can read the limits for yourself.

The app does not change your program and I will not either. What it can do is stop treating a 44-day cycle as an error and start treating it as data.

My wife is the reason Ferrabelle exists, and I built it to learn her cycle and her barbell together. In perimenopause both of those can change at once, so the app has a mode for 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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