Perimenopause in your 40s: early signs and training changes

You are sleeping worse, your cycle has dropped to 24 days, and a bar you pulled for five reps last year now feels heavy for three. Somewhere between 40 and 48, the question is usually the same: is this perimenopause, and what should change in the gym? Some things should change — fewer than the internet suggests, and more specific.

What perimenopause is, and when it starts

Perimenopause is the stretch before your final period, when the ovaries start working unevenly. Oestrogen does not glide downwards. It swings, sometimes higher than anything you saw in your thirties, then drops sharply. Progesterone tends to fall earlier and more steadily.

For most women it begins between 40 and 47 and runs for four to eight years. Menopause itself is just a date on the calendar: twelve months without a period. Everything before that is perimenopause, and that is where most of the symptoms live.

No blood test settles it. Hormone levels move week to week, so in practice the picture comes from your age, your cycle pattern and what you are feeling.

The signs women notice first

The earliest reliable sign is a change in cycle rhythm. If cycle length varies by seven days or more from one month to the next, that is a textbook early pattern.

• Shorter cycles than before (24–26 days), or a skipped month
• Heavier or longer bleeding, and cramps worse than you are used to
• Waking around three in the morning and struggling to get back to sleep
• Hot flushes and night sweats, often first in the days before a period
• Irritability or anxiety that does not feel like you
• Stiff joints in the morning, shoulders and knees in particular
• Slower recovery: soreness lasting three days instead of one
• Fat shifting to the waist with no change in food or training

No single sign means much. Three or four together, at this age, usually do. If cramps are the main complaint, some exercise does genuinely reduce period pain, and the difference shows up within a couple of cycles.

Strength work stops being optional

This is the change with the biggest payoff. Oestrogen is involved in maintaining muscle, bone and connective tissue, so as levels start falling, the body responds less to easy training. The signal has to get louder.

In practice: two to three strength sessions a week, 45 to 60 minutes each, built around big movements — squat, deadlift, press, row, lunge. Main lift for 3–5 sets of 3–6 reps, at a load where you could have managed one or two more. Then two or three accessory exercises in the 8–12 rep range.

If your training so far has been light weights and high reps, this is where most of your gains are waiting. Learn the pattern with an empty bar rather than by feel — the fastest fix for a messy deadlift is going back to a bare bar for two or three weeks of clean reps before you load a plate.

Progress will be slower than it was at 32. That is not failure. What actually shifts between your twenties, thirties and forties is not whether you can get stronger, but how fast it happens and how much recovery sits between sessions.

Bone wants impact, not just iron

Bone loss speeds up in late perimenopause and in the first years after the final period. Heavy lifting helps, but bone responds on top of that to short, sharp impact.

Twenty to fifty landings, two or three times a week, is enough — hops on the spot, skipping, a low box jump with a stepped descent. Total time, about three minutes. If your knees complain or you have pelvic floor symptoms, start at ten small hops and build from there.

Cardio: less chasing, more structure

Aim for roughly 150 minutes of moderate cardio a week — uphill walking, bike, rower, any pace where you can still talk in full sentences. Add one interval session: 4–6 efforts of 2–3 minutes at a hard but repeatable pace, with equal rest.

The common mistake is swapping strength sessions for longer cardio when the scale creeps up. That works against you. Cardio is there for your heart and your head; lifting stays the foundation.

Hot flushes during training are normal. Layers, a cooler room and drinking before you actually feel thirsty all help, since night sweats count towards your daily fluid balance too.

Protein, sleep and recovery

Protein: 1.6 to 2.2 grams per kilogram of body weight a day, split across three or four meals of 30–40 grams each. A blunted muscle response to food and training means small servings no longer do the job they once did.

Creatine monohydrate at 3 to 5 grams a day is one of the few supplements with convincing evidence behind it for strength. The usual thing that puts women off is the water-retention worry, and it is mostly misplaced.

Sleep is half the story. Stop caffeine before 2pm, expect alcohol to make both flushes and night waking worse, and keep the bedroom colder than feels reasonable. Build in one easier week every five to six weeks of training, because fatigue accumulates more quietly now than it used to.

When to see a doctor

Get checked if bleeding soaks a pad or tampon every hour for several hours in a row, if you bleed between periods or after sex, if cycles keep coming in under 21 days, or if any bleeding appears after a full twelve months without a period.

The same applies to symptoms that are wrecking daily function — sleep, mood, flushes. There is treatment worth discussing, hormone therapy included. Chest pain, breathlessness or feeling faint on exertion are not perimenopause and need urgent assessment.

The short version

• The first sign is an irregular cycle rhythm, not hot flushes; age and symptoms confirm it, blood tests do not.
• Two to three strength sessions a week, main lift 3–5 sets of 3–6 reps at a genuinely heavy load.
• 20–50 landings two or three times a week for bone, about three minutes in total.
• 1.6–2.2 g of protein per kilogram daily in 30–40 g servings; creatine 3–5 g a day.
• Cardio adds to strength rather than replacing it: 150 moderate minutes plus one interval session.