Building Muscle in Midlife: Hormones Explained

Dr. Rebeccah Hertel, a family medicine physician trained as a DO (doctor of osteopathy), once fixed a stiff neck for Dr. Kelly Casperson in a hotel gym, mid-workout, using a technique called HVLA, or high-velocity, low-amplitude thrust (04:09). It took almost no force. Hertel found the right fulcrum, applied a small push, and the problem was gone. That small scene sets up the whole episode: the body, even in midlife, responds to the right input applied correctly. The trouble is that most of medicine still treats midlife women's bodies as a mystery to be managed rather than a system that can be rebuilt.

Hertel knows this from her own body. Around age 40, she told Casperson, she felt like she woke up one day and her muscle definition was simply gone. There was fluid retention in her legs. The circuit training that had kept her toned for years stopped working (12:37). What fixed it wasn't more effort of the same kind. It was less cardio, heavier weights than she had ever lifted, and better sleep and diet (13:36). She started hormone therapy around the same time, in her mid-40s, which she says helped too, but the training change came first and mattered on its own.

This is the quiet thesis running through the conversation: midlife bodies need different inputs, and most women are never told what those inputs are. Casperson pushes the point further with an analogy from dentistry. Orthodontists, periodontists, and dentists built an entire culture around prevention, straightening teeth decades before a problem shows up. Mainstream medicine, she argues, treats prevention almost as a dirty word, telling patients not to bother with a bone density scan before 65, as if the goal is to wait for suffering rather than head it off (15:12).

Insurance doesn't care about you when you're 80, because that's gonna be bankrupt Medicare's problem. (19:16)

The economics explain some of the resistance. The average American keeps the same health insurance for about four years, so insurers have little financial reason to pay for anything that pays off decades later (18:51). That mismatch between who pays now and who benefits later is, Casperson and Hertel argue, a big reason supplements and out-of-pocket prevention are booming while mainstream medicine lags.

Nowhere is the cost of that lag clearer than in hip fractures. One in two women over 50 will have a fracture of some kind. Sixty percent of hip fractures happen in women, and 25 to 30 percent of people who break a hip do not survive the first year afterward (22:35). Hertel says almost none of her patients have ever heard these numbers before she tells them. The prevention work, she notes, has to start decades earlier, in a woman's 20s and 30s, not after the first fall.

The Hormone Math

Getting the timing and dosing of hormone therapy right turns out to be its own kind of puzzle. A premenopausal, cycling woman might feel completely normal with an estradiol level of 150 to 200 picograms per milliliter. A woman many years past menopause can feel sick on a dose that only gets her to a fraction of that (24:38). Casperson's own clinical marker, not a published guideline but her working rule of thumb, is that bone loss often starts once estradiol drops below about 40 pg/mL, with 30 pg/mL generally considered the post-menopausal range (26:05). That is why she checks estradiol quarterly during perimenopause, trying to catch a woman before she falls into post-menopausal territory rather than waiting until symptoms force the question.

For women further from their last period, both physicians preach starting low and going slow, often with a 0.025 milligram estradiol patch, sometimes lower, because jumping in with a stronger dose like 0.0375 can make a sensitive patient feel so unwell that she quits hormone therapy altogether and warns her friends off it too (24:16). The practical picture is complicated further by generic drugs. A 0.05 milligram patch from one manufacturer and a 0.05 milligram patch from another can produce very different absorption, despite carrying the same labeled dose, a problem both doctors say they have seen firsthand with ongoing patch shortages (33:51).

Testosterone gets its own close look, mostly because Casperson is frustrated by how often she hears that there is no data on it. There is. A 2026 retrospective analysis in the Journal of the American Academy of Orthopedic Surgeons found that testosterone replacement therapy was associated with a 40 percent lower incidence of hip fracture in men and a 50 percent lower incidence in women, with women on the therapy about 1.9 times less likely to break a hip (52:48). A separate randomized, placebo-controlled trial published in JAMA found that women in their 70s given testosterone after a hip fracture had, at six months, less visceral fat and a 50 percent lower risk of needing a cane or walker, a marker tied directly to living independently (53:11).

Don't tell me there's no data. I'm so fucking sick of there's no data. (52:48)

The two physicians also take apart the research that midlife hormone caution is usually built on. The Women's Health Initiative, or WHI, the large federal study behind most of the current hesitation, used an oral synthetic hormone formulation that is rarely prescribed today. Its 20-year follow-up found no increased risk of heart disease or stroke within 20 years of menopause, a point the original headlines missed (69:16). The HERS and HERS2 trials, published starting in 1998, followed women averaging 67 years old who already had heart disease, comparing oral Prempro to placebo. After an average follow-up of 4.1 years, there was no increased risk of heart disease, death, or cancer compared to placebo. An open-label extension, HERS2, followed the same women to an average age of 73 and still found no difference from placebo (74:36). In other words, the data most often cited to justify withholding hormone therapy from women over 60 does not actually show the harm it is used to argue against.

What the Labs Don't Know

If the research is messier than the headlines suggest, so are the lab numbers doctors use day to day. Casperson says she emailed Quest Diagnostics asking for the reference papers behind its testosterone ranges for women. The answer: there were none. The range was built in-house, not from published research on what testosterone levels actually look like in healthy women (80:10). That matters because a testosterone result marked "high" in red on a lab report can trigger a doctor to stop a treatment that is actually working well for a patient.

Blood levels are also noisier than most people assume. Casperson describes a friend who had her testosterone drawn three times in one sitting, at the same time of day, and got results that varied by about 20 percent (82:11). That is why she leans on a plant analogy she has used with patients for years.

Think of the lab values as the soil. How's the plant doing, right? (83:22)

Soil can be slightly dry or slightly wet on any given Tuesday without harming the plant, she explains. It is the pattern over time, not a single number, that matters. The same logic, she argues, should apply to how doctors read a single testosterone or estradiol level.

None of this is only about numbers on a page. Casperson tells the story of a patient who asked whether a couple of extra years of life were even worth the effort, since 74 versus 68 did not sound like much. A colleague's answer stuck with her: modern medicine will keep a person alive regardless, but that life might not be one worth living.

You don't get it. Modern medicine will keep you alive, and that quality of life might suck. (49:34)

That is the real argument underneath all the lab values and study citations: the goal was never just a longer life, it was a stronger, more capable one. Casperson puts the mindset question in simpler terms, borrowing a line she cannot quite place the author of.

Whether you think you can or you can't, you are right. (59:09)

Six months of heavier lifting to gain a few pounds of muscle sounds slow against a culture built on same-day delivery. But the alternative, both doctors point out, is the version of aging where a person cannot get up the bleacher steps without sliding down on their hands. That is the trade the conversation keeps circling back to: slow, deliberate, well-dosed effort now, against a frailty that arrives quietly and all at once later.