Regaining your strength after 40: why muscle mass changes everything

From the age of 30, you naturally lose between 3 and 8% of muscle mass per decade. Without targeted intervention, you can lose up to 30% of your muscle mass between the ages of 40 and 60, a
loss that accelerates sharply with the drop in oestrogen levels at perimenopause.

This loss has a name: the sarcopenia. It is silent. No warning signs, no pain. That is precisely what makes it so insidious: you only realise it has already begun to compromise your mobility, balance, and independence.

Why does this acceleration happen around perimenopause? Because the oestrogens are directly involved in muscle protein synthesis. As long as they are present in sufficient quantities, the body builds muscle more easily. When they drop, the balance tips the other way: breakdown becomes faster than construction.

Even the quality of muscle fibres changes. With high oestrogen levels, the body tends to produce fast-twitch fibres (type II — power and speed fibres). As oestrogen declines, it shifts towards endurance fibres. Yet it is precisely the fast-twitch fibres that allow us to catch ourselves when we stumble, climb stairs without effort, carry loads, and generate the force that stimulates
bone density.

What is at stake at 40 is therefore far more than a question of "staying in shape". It is the physiological
foundation of the next twenty or thirty years of your life.

That is also why preparing for the menopause from your forties onwards becomes a major issue in
women's health.

For a long time, muscle was thought of as a simple contractile tissue: it's there to move you, full stop. Recent science tells a far richer story.

Muscle is now recognised as a fully-fledged organ, with three major vital functions.

A metabolic organ. The more muscle mass you have, the more effectively your body regulates blood sugar and insulin. Muscle is also the main driver of your resting metabolism: it "burns" constantly, even when you're not moving. And it is the only tissue capable of burning fat significantly. Without sufficient muscle mass, losing body fat becomes extremely difficult, if not impossible.

A hormonal organ. When you contract your muscles, they release signalling molecules called myokines. These myokines communicate in real time with your brain, your bones, your liver, your blood vessels. They modulate inflammation, protect the heart, and support bone health. Muscle continuously sends messages to the rest of the body. The more active and developed it is, the more numerous and beneficial those messages are.

A neurological organ. When you work your muscles, they also secrete a particular molecule, theirisin, which has the ability to cross the blood-brain barrier. Once in the brain, irisin promotes neurogenesis : the creation of new neurons, particularly in the hippocampus, a key area for memory and learning. This is one of the mechanisms by which muscular activity protects against the mental fog of perimenopause, against depression, and against neurodegenerative diseases such as Alzheimer's disease.

Muscle is not an accessory. It is a communicating organ that interacts with your entire hormonal, skeletal, and nervous system.

Muscle mass protects your bones, your heart, your brain and your metabolism. It is inseparable from the oestrogen-muscle-bone trio, which is central to navigating perimenopause and menopause in good health.

Your bones

Every time a muscle contracts, it pulls on the bone via the tendon. This mechanical traction stimulates the osteoblasts, the cells that build bone. The stronger the muscle, the denser the bone. Conversely, a weakening muscle sends fewer mechanical signals to the bone, which then loses density.

This becomes a critical issue at menopause. The drop in oestrogen accelerates bone loss, which can
reach 2 to 5% per year in the first years post-menopause. In perimenopause, some women lose 15 to 20% bone density without noticing it. Result: 75% of hip fractures affect women.

The study LiftMore conducted by Dr. Beck demonstrated that even women with osteoporosis can lift heavy weights without injury, and gaining +3% bone density in the lumbar spine in 8 months, a result comparable to what is observed with hormone replacement therapy for menopause (HRT).

Your heart

The cardiovascular diseases are the leading cause of female mortality, far ahead of all cancers (including
breast cancer). A fact that is still largely under-communicated.

Muscle mass directly improves insulin sensitivity and reduces the risk of type 2 diabetes. The myokines released by active muscles protect blood vessels and reduce chronic inflammation. And contrary to a still-widespread belief, cardio alone is not enough: to protect your heart after 40, building muscle has a more powerful and more lasting effect.

Your brain

Irisin released by muscle promotes neurogenesis. In practice:

• Improvement in memory and concentration
• Protection against brain fog often reported in perimenopause
• Effect preventive effect on depression and anxiety
• Protection against cognitive decline and Alzheimer's disease

Added to this is the muscle's regulatory effect on stress hormones (cortisol in particular). A muscular body
supports a more stable nervous system.

To build muscle after 40, train 2 to 3 times a week, lift heavy enough, incorporate eccentric work, and allow 3 to 5 days of recovery for each muscle group. Cardio alone is not enough — it should be complementary, not a substitute.

Here are the key principles to know.

1. Consistency comes before intensity. Two to three sessions per week, sustained over time, are infinitely more effective than a month of intensive training followed by a prolonged break. Twenty targeted minutes, several times a week, are enough to bring about real change.

2. Lift heavy. Really. The "little pink weights" of 1 kg that have long been presented as suitable for women are insufficient to stimulate muscle synthesis after 40. Personally, I recommend starting starting from a minimum of 4 to 6 kg and to keep progressing. The simple rule: the load should be heavy enough that after 6 to 8 repetitions, you cannot do a single one more. If you still can, it means you need to increase the load.

3. Incorporate eccentric work. Muscle is built most effectively when it is stretched under contraction : that is, during the controlled release phase. In practice: with each movement, slow the lowering phase. Lift in 1–2 seconds, lower in 3–4 seconds. This is one of the reasons why yoga, when it incorporates held postures, works well for muscle mass: warriors, chair, plank are all contractions under stretch.

4. Recovery is non-negotiable. Muscle soreness is made up of micro-tears in the muscle. This is normal — it's even necessary for building. But the body needs 3 to 5 days to repair a muscle group before working it again. Without this recovery, you're not building — you're burning out.

5. Cardio as a complement, not a replacement. Cardio remains useful for the heart and cardiovascular health. But it doesn't build muscle. Practised in excess, it can even contribute to breaking down the muscle mass you're trying to preserve.

6. Yoga and strength training: the winning combination. No single practice is enough after 40. Yoga brings mobility, body awareness, and nervous system regulation. Strength training brings the mechanical load needed to preserve muscle and bone. Together, they build a strong body and
free.

Aim for a minimum of 1 gram of protein per kilogram of body weight per day, spreading your intake throughout the day. Avoid training on an empty stomach and restrictive diets: they break down muscle instead of building it.

Building muscle without sufficient protein intake is simply impossible. For a woman weighing 60 kg, this means 60 g of protein minimum per day, and ideally up to 1.6 g/kg (i.e. ~95 g for 60 kg) if you are actively looking to rebuild.

A point that is often overlooked: women absorb protein more effectively when it is spread throughout the day, unlike men, who can absorb large amounts in one go. It is therefore more effective to aim for 20 to 30 g of protein at each meal and snack, rather than concentrating it all in the evening.

A few concrete benchmarks:    

• One egg = ~5 g of protein only. Two eggs at breakfast = 10 g — far from enough. 
• A portion of fish or meat (100-120 g) = 20-25 g of protein.
• A portion of cooked pulses (200 g) = ~15 g.
• The protein powders (whey, plant-based) are a valuable supplement to help reach your intake targets,
  added to a porridge, a smoothie, or a morning matcha.

Avoid training on an empty stomach. Many studies show that women lose muscle
when they train on an empty stomach. The intermittent fasting is, for the same reasons, best avoided during an active muscle-building phase: long gaps between meals lead the body to draw on muscle mass itself.

Creatine is one of the most scientifically well-documented supplements for pre- and post-menopausal women. It improves strength, muscle mass, and cognitive function, and even supports bone density when combined with resistance training.

Creatine is not an "artificial" substance: it is a molecule your body produces naturally (primarily from red meat). But women produce significantly less than men, and their endogenous stores are 70 to 80% lower. A direct consequence: women
respond particularly well to creatine supplementation, even more so than men.

What the science documents

Smith-Ryan et al. (2021, Nutrients): literature review confirming the efficacy of creatine in pre- and post-menopausal women on strength, performance, and muscle size and function.

Chilibeck et al. (2015): 12-month randomised controlled trial in post-menopausal women. Result: creatine + resistance training → slowed bone loss at the femoral neck (-1.2% vs -3.9% in the placebo group) and a measurable increase in femoral width. Creatine therefore indirectly supports bone health via muscle.

Documented cognitive effects: improvement in cognitive function, reduction in brain fog often reported in perimenopause, support for concentration, and a preventive effect on depression.

Dosage and practice

The standard dose is 5 g/day of creatine monohydrate of quality (the most well-studied form). You can start more gradually (1 to 2 g in the first few days) to allow your body to adjust.

Personally, I have been taking creatine for nearly a year, at 5 g on the days I train (four times a week), and I notice better recovery and more noticeable muscle progress than before. I should clarify: this is not a prescription, but a personal account. Do your own research, consult a professional if you have any particular health conditions, and choose a quality product.

At menopause, cartilage thins and synovial fluid decreases. To keep lifting weights and doing the impact activities that protect your bones, your joints need to stay mobile and resilient.

If muscle mass is the foundation, joints are the hinge that allows the whole system to function. Yet at menopause, several changes directly affect your joint
health:

• The cartilage thins    
• The synovial fluid decreases
• Oestrogen no longer plays its role anti-inflammatory
• The risk ofosteoarthritis risk increases and women are more exposed to it than men

Prioritise active mobility

After 40, flexibility shouldn't be the priority — what matters is active mobility: being able
to control movement through its full range, not just being passively stretched.

• Passive mobility (sustained stretches, yin yoga) useful for recovery and the nervous
  system.
• Active mobility (controlled joint rotations, load-bearing movements through full
  range of motion) — this is what strengthens connective tissues and stabilises
  joints. To be prioritised.

Nutritional support

Several molecules are documented to support joint health:

• Omega-3s (fish oils, flaxseed, chia): well-established anti-inflammatory effect.
• Curcumin (bioactive form of turmeric): beneficial for joint pain.
• Type II collagen: a natural component of articular cartilage. Recent studies suggest a positive effect on joint flexibility and comfort, particularly alongside regular physical activity.
• Vitamin D (2000 IU/day often recommended as a supplement): essential
  for bone and muscle.

Here too, do your own research, ideally based on tests (blood or hair analysis) rather than supplementing blindly.

If there is one thing to take away, it is this: it is never too late.

Recent studies show significant improvements in strength and bone density in women in their sixties, their seventies, and beyond. Dr. Stacy Sims, physiologist and specialist in women's health, documents cases of women with osteopenia or osteoporosis who, after 6 to 8 months of progressive load training and plyometrics, regain normal bone density.

The muscular and bone gains achieved through exercise are comparable to those of hormone replacement therapy for menopause (LiftMore study, Dr. Beck). For women for whom HRT is not indicated or not desired, this data is invaluable: resistance, impact and nutrition can take you far.

Regaining your strength after 40 is not about trying to stay young. It is a choice of foundation, the one on which you will live the next twenty, thirty, forty years of your life.

It is also an act that goes beyond the individual sphere. Our culture has long kept women away from strength, teaching them that they should be slim rather than solid, slight rather than stable. My own mother wore a size 8, my grandmother a size 6. And when I started building muscle, my mother said to me: "Don't get too muscular — it won't look nice." Building muscle mass is today an act of health. It is also a political act. A return, in short, to the sovereignty we hold over our own bodies.

The female hormonal system is at the centre of everything: it communicates with your musculoskeletal system, your nervous system, your cardiovascular system, your digestion, your immune system. Every pillar you strengthen supports the whole. Muscle mass is not an end in itself: it is a deep form of support for your foundation, to help you navigate perimenopause and menopause with as little difficulty
as possible.

Menopause is not an illness. It is a transition that nature intended, and that the female body has the capacity to navigate. Our role is to give it the foundations it needs to do so.