According to epidemiological studies in the UK, one in two women over the age of 50 will suffer an osteoporotic fracture in their lifetime. It is one of the most cited statistics in women’s health and simultaneously one of the least absorbed. It doesn’t feel real until it is, until the boot goes on, until the vertebra collapses, until the hip fracture at 74 that precedes, in 20 to 24% of cases, death within the year.

The reason it doesn’t feel real, in part, is that the conversation about bone health tends to reach women too late, framed around treatment rather than prevention, and anchored in an age range, post-65, post-fracture, when the window for meaningful intervention has already started closing.

Dr Carrie Pagliano has been watching this happen for 26 years. And something that surprised me during our conversation was that running doesn’t do much for your bones.

“Surprisingly enough, running does not do much to help with bone density. It’s right up there with swimming, to be honest, which is really surprising.”

This is where the conversation about bone health for active women gets interesting and urgent.

The Window

Bone is not static tissue. It is constantly being broken down and rebuilt, a process called remodelling that is exquisitely sensitive to mechanical load, hormonal environment, and nutritional status. The critical period for building peak bone mass is childhood through to the late twenties. “Most of our bone health is built up to age 30,” Pagliano says. After that, the capacity to increase bone density diminishes, though it doesn’t disappear. “We have the ability to alter and modify it, improve it, up through menopause.”

This is the window. It is not closed after 30. But it is narrowing. And the behaviours that matter most for protecting bone in midlife, specifically the kind of mechanical loading that actually stimulates bone remodelling, are not the ones most active women are doing.

Swimming: minimal skeletal benefit. Cycling: minimal skeletal benefit. Running: less than people think, because despite the repetitive impact, the loading stimulus per step is not sufficient to drive meaningful bone adaptation at the intensities most recreational runners train at. What drives bone remodelling is heavy load or high impact, think ground reaction forces of multiple times bodyweight, applied rapidly.

Think jumping. Think heavy barbell work. Think the things that also, inconveniently, tend to make perimenopausal women leak.

The Plyometrics Catch

This is the clinical trap Pagliano watches active women fall into repeatedly. They get the message, finally, after years of the evidence being ignored in mainstream women’s health, that they need impact training and strength work to protect their bones. They go to the gym. They start jumping. They leak. They stop.

“They’re trying to do the right thing, but then this pelvic floor catch comes up.”

The leap she needs them to make is that the leaking is also fixable, that it’s not an immutable feature of their postpartum or perimenopausal body, but a coordination problem with an intervention. The pelvic floor and the skeleton are not in opposition. Solving one does not mean sacrificing the other. But the two problems need to be addressed in the right sequence, and most women never get told that both conversations can be had, let alone simultaneously.

Powerlifting adds another layer. Women lifting heavy enough to compete, loading the spine and hips with multiples of their bodyweight, occasionally develop leakage not because something has gone wrong, but because the system is being pushed to its limit. “In some situations, it’s because they’re lifting so, so, so heavy, just the system’s being overloaded.” This is a different problem from perimenopausal leakage. It has different solutions. The existence of both presentations in the same category, women who leak during exercise, is part of why the generic advice is so unhelpful.

The Scan Question

In both the UK and the US, a DEXA scan, the gold-standard measure of bone mineral density, is not routinely available until 65. Pagliano is direct about what she thinks of this. “It’s almost too late at that point.”

She got her own scan early because of family history. She describes navigating the system, finding the right primary care physician who would tick the right box to get insurance to cover it, knowing a colleague who runs body composition scans for figure athletes and includes bone density as part of the panel. This is the reality for women who want this information before menopause: it requires knowing where to look, having the right conversations, and often paying out of pocket.

For women without that access, history does significant work. A previous stress fracture. A history of disordered eating or underfuelling. Irregular or absent periods. These are the signals that should trigger the conversation much earlier, regardless of what the system offers.

“I have never seen so many women walking around in boots,” she says, meaning the orthopaedic boots that follow stress fractures. “This just doesn’t seem right.”

The Skinny-Is-Fast Reckoning

The stress fracture conversation leads somewhere darker, and Pagliano follows it there without flinching.

She’s talking about a generation of female distance runners, her generation, who trained through an era in which low bodyweight was synonymous with performance. “Skinny was fast, or was supposed to be that way.” The fuelling strategies of the 1990s and early 2000s recreational running scene were not strategies at all. They were restrictions, often bordering on or crossing into disordered eating, normalised by a culture that rewarded lightness.

She mentions Kara Goucher’s memoir and Lauren Fleshman’s book, both elite athletes who have written candidly about underfuelling, stress fractures, and the long shadow of those years. “They don’t call it low energy availability. They don’t identify it as that at the time, because we didn’t know.” What we now call RED-S, Relative Energy Deficiency in Sport, was, in that era, called thinness. Sometimes it was called discipline.

The damage, it turns out, is not always contained in the past. Pagliano references research, published in the last couple of years, suggesting that disordered eating patterns can resurface in ultra runners in later years. Body image pressure doesn’t disappear at perimenopause, it often intensifies, as bodies change in ways that are rapid and unasked for. “Body image is a huge issue going into perimenopause and menopause because things are changing, random weight gain out of nowhere, that kind of stuff.” The threads carry through. They don’t dissolve.

For women who got through their twenties and thirties running hard on not enough food, the bone density story is more complicated. The window for building peak bone mass was precisely the period in which their nutritional status was compromised. What they’re managing now is not just normal age-related loss, they may be starting from a lower baseline than they realise, at an age where the tools for recovery are more limited.

This is where the DEXA conversation becomes not just useful but necessary.

The GLP-1 Signal

There is a newer strand to the bone and muscle conversation that Pagliano raises. She is beginning to have DEXA discussions with patients who are starting GLP-1 medications, the weight loss drugs now being prescribed at scale to women in midlife.

“We know that muscle mass is going to drop.” The evidence on GLP-1s and lean mass loss is consistent enough that she is now recommending baseline scans before patients start, to have the data to monitor against. She describes putting her hands on a patient she’d been working with for some time, who had been on a GLP-1 for a while without her knowledge. “Just the quality of her muscles felt like she was 70 and she was 40. And that just, at the time, I couldn’t process it.”

She is not making an argument against GLP-1s. She is making an argument for not starting them in a data vacuum. Muscle mass and bone density are not vanity metrics, they are functional longevity markers. If a drug is changing them, you need to know where you started.

Doing the groundwork

The answer, unglamorous as it is, is heavy loading and impact. Progressive resistance training with barbells. Plyometrics, jumping, bounding, hopping, applied progressively and with enough volume to drive bone adaptation. Weighted vests have some evidence behind them, particularly for postmenopausal women, though the perimenopausal research is thin. “Almost all the research is on postmenopausal women,” Pagliano notes. “Perimenopause is different, hormones are in flux, bone loss starts, and everyone’s experience is unique.”

The research is catching up. It is not there yet. Her clinical advice in the interim: don’t wait for it.

“Start strength training now while the research catches up.”

She has been lifting for ten years, since after her hip surgery, a labral repair following marathon training eighteen years ago. The surgery was the consequence of a running life built without the counterbalance of strength work. “I got better after I started lifting weights.” The pivot was personal as much as professional.

The women she treats are, increasingly, the same story at a different stage. They have run for decades. They are now being told, firmly, that running is not enough. The gym is unfamiliar territory. The equipment is unfamiliar. The culture can feel alien. And then, when they try the jumping, they leak.

The answer to the leaking is in Part 1. The answer to the bones is: start now, load heavy, don’t let the leaking stop you from doing the thing that the leaking is interrupting.

Both problems are solvable. That’s what 26 years in this field teaches you.

Part 3: low oestrogen, different decades.