Strength training does more for women than any other kind of exercise

If you could only do one form of exercise for the rest of your life, the evidence points fairly clearly at resistance training. Not because cardiovascular fitness does not matter — it matters a great deal — but because strength training covers a wider set of outcomes that specifically deteriorate with age and specifically affect women.

Most women still do far less of it than men, and a good deal of fitness marketing aimed at women is still oriented toward being smaller rather than stronger.

Bone

This is the strongest single argument.

Bone responds to mechanical strain. Loading it above the level it is accustomed to signals adaptation; not loading it signals that less bone is needed. Walking and swimming, whatever else they offer, provide relatively little osteogenic stimulus.

The years around menopause are the period of most rapid bone loss in a woman's life. Trials of progressive high-intensity resistance and impact training in postmenopausal women — including women who already had low bone density — have found maintenance and in some cases improvement in bone mineral density, which was long assumed to be impossible after the transition.

The load has to be meaningful. Light weights for high repetitions do many useful things and do relatively little for bone. What happens to your bones around menopause covers the timing.

Muscle, and what it is actually for

Muscle mass declines from around the fourth decade, accelerating with age and accelerating further around menopause as oestrogen's anabolic support falls away.

Muscle is not primarily aesthetic. It is:

• The main site of glucose disposal, which is why muscle mass is one of the strongest predictors of insulin sensitivity
• The determinant of whether you can get off the floor, carry shopping, catch yourself when you trip
• Metabolically active tissue and a reservoir of amino acids during illness

Grip strength — a crude proxy for total muscle function — is one of the better predictors of all-cause mortality in older adults. That is not because grip matters; it is because it indexes something that does.

Metabolic health

Resistance training improves insulin sensitivity substantially, and does so partly independently of weight change. This is particularly relevant in PCOS, where insulin resistance is a core mechanism rather than a complication — PCOS beyond the ovaries.

It also improves lipid profiles and blood pressure, though aerobic training has the edge there.

Mood and cognition

Randomised trials of resistance training in depression and anxiety have found effects that compare respectably with other interventions. The mechanism is not fully understood and probably involves several things at once — but the effect is not simply "exercise makes you feel better", because it shows up on structured outcome measures. What actually helps anxiety.

The two objections

"I don't want to get bulky." Substantial muscle hypertrophy requires a large training volume, a sustained calorie surplus and, for the physiques people are picturing, usually pharmacology. The realistic outcome of two or three sessions a week is a body composition that most people describe as leaner, plus considerably more capability.

"Lifting heavy is dangerous, especially as I get older." The injury rate in supervised resistance training is low, comparable to or lower than most recreational sports. And the risk calculus runs the other way with age: the thing that ends independence is usually a fall and a fracture, and both are made less likely by stronger muscles and denser bone. Being cautious about load in your sixties is, in most cases, exactly backwards.

What it actually takes

Less than most people assume. Two to three sessions a week, 30 to 45 minutes, covering the major movement patterns: a squat, a hinge, a push, a pull, and something for the trunk.

The non-negotiable ingredient is progressive overload — the load, reps or difficulty has to increase over time. Doing the same workout with the same weights for two years is a habit, not a stimulus. This is the single most common reason people train consistently and see nothing.

Protein intake matters for adaptation, and most women eat less than is optimal for it — how much protein women need.

Some specifics

Postpartum, resistance training is one of the most useful things for restoring function, but impact and heavy loading should follow pelvic floor assessment. The fourth trimester and the pelvic floor is a muscle group.

Around your cycle, the evidence for periodising training by phase is much weaker than the internet suggests. Training around your cycle is honest about it. Consistency beats optimisation.

Underfuelling blunts adaptation and, taken far enough, suppresses the reproductive axis — how stress affects your cycle.

Track the load, not the feeling

Progressive overload requires knowing what you lifted last time, which sounds trivial and is where most training programmes quietly fail.

It is also worth tracking against the rest of your life. Perceived exertion at the same objective load varies with sleep, cycle phase, stress and iron status — and a session that felt terrible is not evidence that you are getting weaker if the numbers say otherwise.

Naked is built to hold that context: training alongside sleep, cycle, energy and mood, so you can see what actually drives your good and bad sessions. For most people the answer turns out to be sleep, and it is not close.