 OK, so I'm a medical historian, primarily trained in humanities, but also having done some biomedical science study. And I'm working on a big project at the moment about the history of medical ideas, about sex-differentiated aging, how we came to have these concepts of menopause and andropause, and what kind of concepts preceded them in the history of medicine. So that's the background to my interest in questions of hormone replacement therapies. In this talk, I'm mainly going to focus on menopausal hormone replacement therapies. I'm very interested in all the other ones as well, and certainly have been doing some work on testosterone men's hormone replacement. But in this talk, I'm really just going to focus on the women's issues. OK, so I'm going to roughly cover this territory, a bit of an intro, some historical background, looking at some of the research on the benefits of estrogen replacement for women, and also about some of the questions of its safety, which has been very controversial. I want to give you some ideas about where you can find good information on this topic, because one of the things that's very clear when you first start reading about estrogen replacement is that there's a tremendous divide, both among the scientific researchers working on this topic and among various popular mediators of the science, so that you have a camp who are massively anti-estrogen and think it's terribly unsafe and it's going to give you cancer and cardiovascular disease and dementia. Nobody should ever take it. And then you've got people on the other end of the spectrum who think everyone should get on it roughly from the end of their 40s and just stay on it for the rest of their life, because it's going to prevent cardiovascular disease and osteoporosis and breast cancer. So how do you make sense of that? I mean, it's difficult for me as a historian just to work out how we end up with this massive dichotomy in the research and in popular ideas. And so I thought, well, how hard must it be for a woman who might feel the need for some kind of hormonal support to make a decision about whether that's appropriate, whether it's concordant with living an ancestral life way? So the first thing I feel like I really have to say in talking about this topic is that menopause itself definitely is ancestral. This is actually a really strange myth that I see reiterated by some scientific researchers, even people you think would really know better. They say things like, this is the first time in history that women have outlived their ovaries. That is not true. So here there is masses of historical evidence, masses of anthropological evidence that in all human societies there have been significant numbers of women living beyond their reproductive years. And in fact, I talked about this at last year's ancestral health symposium. There's very good support for the notion that humans evolved menopause in the first place because it had a unique evolutionary benefit. Okay, so sometimes people make this claim, I think that we are the first people to have problems with menopause because we're the first people to live old enough. They make this claim as a justification for why it's perfectly natural to want to replace the estrogen when you run out of it. So when I started thinking about this question, I thought, well, that's not true. But maybe it is true that modernity produces pressures on our endocrine system of the kind that make menopause particularly difficult. So maybe there are things that are disrupting a hormone balance that are making it more symptomatic as an experience of transition. But then when I read a lot of the material about endocrine disruption, of which there is some very interesting science, I noticed that actually almost none of it talks about menopause. And it is almost entirely focused on fertility and hormone questions of people of reproductive age. And there's also this curious thing about it which is that most of the endocrine disruptors are estrogenic. So what does that mean for someone who's estrogen deficient? There are some really strange ambiguities about that problem, I think, for menopausal women. And at stake in this question, I guess, is this divide that we tend to make between interventions that are specifically remedial for problems that we have in the context of modernity and then things that we might do to kind of biohacker biology in order to squeeze more out of life. So is HRT remedial or is it biohacking? I'll be biohacking aging when we try to take hormone replacement therapies for age, normal aging related questions. So just quickly, I wanna just talk about four big categories of things that come up repeatedly in the research as recognized stresses on the female endocrine system in general. And it proposed that maybe what we are seeing in terms of the pressures of modernity might be less to do with endocrine disruptors and more to do with other actually changeable lifestyle factors that are affecting large numbers of people. Sleep loss, chronic under nutrition, chronic stress and low soluble fiber diets. So the research on sleep loss is very robust. We know that there are immediate effects on the sex steroid hormone system in both men and women when people are sleep deprived as an immediate drop in the sex steroid hormones. Chronic under nutrition is also very well studied as a disruptor of the female hormonal system and in fact there's very good long historical evidence of this as well. So one of the main preoccupations of medical scholars all throughout ancient and early modern history was the problem of amenorrhea in women of reproductive age. Women who lost their menses and lost their fertility because they couldn't get enough to eat. Now we don't have the problem that we can't get enough to eat in the modern industrial world. We have a problem of an ideal of skininess that women are trying to aspire to and so they're starving themselves in the chronic often in the chronic situation of chronic over exercise. So the fiber question is obviously kind of complicated because when you look at research on fiber it's often unclear what kind of fiber is being talked about. There's a big difference between the sort of resistant brand that doesn't feed anything and the non-starch polysaccharides and resistant starches that you find in vegetables that nourish a good gut microbiome. So I'm not quite sure what to make of all of that side of it. But I just wanna paint a bit of a portrait for you and see if this sounds sort of familiar like somebody maybe you've met at some point in your life. Let's call her Karen. She's 45. She's always been pretty trim but in recent years she's put on a bit of weight. She decides she's gonna get into CrossFit, eat a ketogenic diet. She's got three kids and a full-time job. She's sleeping six hours a night and mainly eating protein bars. Does that sound like you've never heard of anyone doing anything like that? Okay, so I just wanna put that out there that maybe there are some issues in the way people are living even in the ancestral health community that could be pressures on the endocrine system as we age. Okay, let's think a bit about the history of all this because HRT obviously is a 20th century innovation. It's extremely historically novel but there has been a form of endocrine therapy that long, long predates it. And this is what in medical history we call organotherapy, the use of animals organs as pharmaceuticals. So from the second century, the Roman Greek physician Galen of Pergamon recognized that the gonads of animals, the testes of male animals and the ovaries of female animals had a massive impact on their behavior in that if you removed them, you no longer saw the mating behaviors, you no longer saw the sexual seductions, you no longer saw them receptive to sexual interest. And so he speculated that these are the organs that really are generating a lot of the force of our behavior. Alter out the period from about the 1500s until the end of the 1800s, you have the use in European pharmacy of animal gonads. These are in the form typically of fox or goat penis, bulls, testicles. These things would be dehydrated, ground up and made into little pills or sometimes mixed into an ointment that was applied topically to the genitals. And so these treatments, you can find them in all the early modern apothecary lists and they're usually prescribed for fertility. So they're prescribed as aphrodisiacs, but in the early modern concept, the whole point of sex was to make babies. So an aphrodisiac was a fertility remedy, which is not to say people didn't use them for other things, but that was how they were sold. And the reason they thought that these organs would do that is because of this concept that we call the sympathetic model of medicine, like we treat like. So if you can get the gonads of another animal that seems to be kind of horny, that might do it for you as well. And you actually find a parallel of this in ancient Chinese medicine as well and traditional Chinese medicine, the tradition known as Yi Jing Bu Jin, which is also the use of organs as medical remedies. And in the Chinese tradition, that's typically tiger penis or sea or penis. Now there's a question about how much these kind of remedies would have had hormonal activity because certainly when you're talking about an oral intake of hormone-rich substances, not all hormones can be taken up in that form. Testosterone has no oral uptake capacity at all until we get modern synthetic forms like methyl-testosterone. DHEA possibly somewhat, estradiol possibly also somewhat. But it's very unclear, we don't have samples of what they were using and it wouldn't be, we wouldn't necessarily be able to tell how potent they were at the time anyway. So certainly the organotherapy tradition is not as aggressive, wouldn't have been as strong as a remedy as modern forms of hormone replacement therapy. But there is a precedent to it, there is a kind of ancient lineage to the idea that we can intervene in our endocrine system in this way. So the real ball started getting kicked off in the 19th century in 1849 with a German zoologist called Arnold Aushoff-Belthold who castrated roosters and then reinserted the testes back into some of them. And he observed these very powerful behavioral reactions in those procedures and that the castrated roosters really started behaving like chickens and just pecking around and forming part of the hierarchy of the other females. And then when the testes were put back in, they again began to act like roosters and strut around and crow and all that. So this research was very generative, a lot of other people did work of a similar kind. And then in 1889, a rather idiosyncratic Franco-American physician called Charles-Edouard Brancécar decided he was gonna actually inject himself with the testes of guinea pigs. Imagine that thinking that's a good idea. And so he made an extract of guinea pig testee, he administered it to himself and then he reported what he experienced from those transplants which was a sense of increased vigor, greater muscle tone and strength, a greater nervous excitement by which you can kind of implicitly read, he was a little bit more sexual. And this was published in The Lancet and it triggered a great deal of excitement. And so a lot of other researchers then replicated his experiment doing, practicing this on a group of elderly men observing similar results. They claimed to be doing a placebo-controlled trial. It's not entirely clear to me that there would have been a real placebo because it kind of does feel different if you get injected with testes extract compared to saline, but there it was. And so that triggered a whole lot of new research. So the reason I think this is interesting is because when I started looking at the history of HRT, it occurred to me that I wonder what, at what point when people discovered the sex steroid hormones, how quickly did it occur to them to try and sell them as a commercial product? Might that be straight away or might it be some time afterwards? And I was really surprised to discover the answer which was way before, way before they discovered the sex steroid hormones, there was a commercial market for these products. They didn't know what was in them, they didn't know why they exerted this activity, but they were going for them nonetheless. And so very quickly after all of this started happening, you see products appearing on the European medical market that are quite popular and form a really significant market. So the bull testes extracts, you see them all through America and Europe from about 1900. In 1927, the Chicago physiologist Fred C. Koch actually isolated testicular substance. So he found the molecule, he didn't know what it was and he can give it a name. But then in 1935, the Dutch pharmaceutical company, Organon, actually managed to synthesize that molecule and named it testosterone. And throughout this period, I mean initially, I think at the beginning of the 1930s, there was this idea that men have testosterone and women have estrogen. So there's a man's hormone and a woman's hormone. But very quickly, they figured out this wasn't true and that everybody's got a bit of everything and that actually one of the highest sources of estrogen in the animal world is found in the stallion who has more estrogen than mayors do. So this was all very confusing and they began to look at what testosterone did to both men's and women's bodies. And so there was lots of research conducted in this period on women and testosterone. And in that, they figured out that certain amounts of testosterone, you could create these viralization effects. And similarly, with certain amounts of estrogen in men's bodies, you could create a feminization effect. So estrogen actually had an even earlier history. So there was a proliferation of products of this kind, pills containing ovarian substance from about the 1870s in Europe and they were typically prescribed for gynecological disorders. This one I've got a photograph of was produced in America around 1910. Ovarian substance desiccated, coated in chocolate. And so these were things that you could get from medical clinician up until the beginning of the 20th century and then suddenly the commercial market for them exploded and you could just buy them by mail order, you could get them at the local pharmacy. Anyone could buy them, they were completely unregulated. And then in 1929, so it's around about the same period as testosterone, you have two researchers Adolf Putnam and Edward Doisy who both discover independently this molecule which ends up being named Estrone. Estrone's E1, so you've got the four different types of estrogen, this molecular diagram actually I think is E2 that I've got here. And so then very quickly after the discovery of the estrogens and the naming of them, you have the development of pharmaceutical products that are being prescribed to women for menopausal symptoms. And the idea in this early period was simply that you would take them for a couple of years in the menopause transition, specifically for the treatment of hot flushes and headaches and sleep disturbances. So they were very much about a symptomatic alleviation. And that market was quite substantial, it was a fairly stable market, there were plenty of women who wanted to use it for that purpose. But it seems like the pharmaceutical companies were not quite satisfied with that. And so the idea was circulated that maybe more women could be convinced to take estrogen and maybe the ones who were taking it already could be convinced to take it for even longer. And so throughout the period from the 1960s to the 1990s you had this tremendous hyperbole about estrogen replacement therapy as a kind of elixir of youth. And this idea that hormones can restore our youth, it's something you find really, from the time of Bronzekau, like the guy who injected the guinea pig testicle, he too thought that he was being rejuvenated by a testosterone. And so the products have always been kind of sold on this basis that we can combat aging, we can stop it from happening. Some of you might have heard of this book that was published in 1966 called Feminine Forever by the physician Robert A. Wilson, a book that promoted universal estrogen therapy for women approaching menopause even and for the rest of their lives so that we could stay feminine forever. It wasn't known at the time that this book was published but it subsequently became known that Wilson was funded by IEIST Laboratories, one of the major pharmaceutical producers of estrogen replacement therapies. So it's very clear that the pharmaceutical industry invested heavily in promoting HRT to women using all kinds of very non-evidence claims about its benefits. And of course not even considering the issue of its safety. And so even though this had been debunked, this idea that there is a man's hormone and a woman's hormone, funnily enough from the 1960s onwards almost all of the menopause research becomes focused on estrogen. And the idea that women even have testosterone seems to have been completely forgotten throughout this period and it's just totally, totally about estrogen. So this is kind of weird. And I'll come back to this on a few occasions because women have a whole spectrum of hormones. We don't only have estrogen and estrogen is not the only thing that declines in menopause. But it clearly was the thing that women could be convinced to take most readily through this idea of it as the ultimate hormone of femininity, as the hormone that makes women what she is. And the claims that were made were truly outrageous about what estrogen could do for us. It was supposed to keep us beautiful. It was supposed to stop us from getting fat. It was supposed to improve mood. It was supposed to prevent cardiovascular disease, stop osteoporosis and it was a general anti-aging supplement. So of course who would not want to take it? And this is one of the advertisements from that era, the 1960s for premarin, the conjugated equine estrogen that was sold by IEAS laboratories. And there she is, the slim, happy, joyous, beautiful woman who is defying aging with estrogen replacement. There's another kind of context that I want to bring into this story if you'll bear with me and that is the history of hysterectomy. Why am I going off on that tangent? Well, I want to show you this is somewhat relevant to the problems with the research on estrogen replacement therapies. So from the end of the 19th century you had this concept of women's hysteria and that is the notion that the uterus is responsible for a whole spectrum of mood disorders of mental illnesses and that you could treat women for all kinds of conditions of that kind by taking out their uterus. The idea was that uterus is kind of this troublesome organ that is controlling women's behavior and so if the behavior was problematic you just got rid of the thing. And there was also this idea of course that the only function of the uterus and the ovaries was to make and carry babies. So if a woman had already had children and didn't plan to have any more then it was often just recommended that she had those organs removed even if there was absolutely nothing wrong with them. And we see this all through the 20th century. In fact, it became, even as the concept of hysteria became discredited medically the practice of hysterectomy increased. And from the 1940s onwards in the US and Europe and in Australia hysterectomy often with orophorectomy was ubiquitously practiced as a cancer prophylactic. You don't have any particular risk of getting ovarian cancer but the idea is you should just take those organs out anyway. So this is old stuff, right? Not particularly relevant to us today. Nobody's going and doing that anymore. Wrong. From the Centers for Disease Control Data of 2006 to 2010 11.7% of American women age 40 to 44 have had a hysterectomy. By the age 60 this goes up to 30%. 30% of women have had these organs removed. Over 600,000 a year, hysterectomies, most of these are elective. Why is this relevant? Because the research on the benefits of hormone replacement therapy includes women who have no uterus and ovaries. Would that make a difference to their estradiol levels? Funnily enough, not a huge difference. But it does make a big difference to another very important hormone for women after menopause. Testosterone. So this is a chart that shows you in the black the testosterone levels of an intact woman after menopause in the gray of a woman who's had a hysterectomy, in the white of a woman who's had a hysterectomy with orophorectomy from a study in the year 2000 where they actually considered measuring women's testosterone. Okay, so clearly that makes a very big difference because testosterone overlaps with estrogen in terms of many of the effects that we ascribe to menopause. Bone density, mood, sleep, cognition. So a lot of the benefits that people think they're getting from estrogen, they could be getting from their own testosterone if they left their organs in there. Okay, so I'm gonna have to jump forward because I'm running out of time. I wanna come straight to this question which is hormone replacement therapy, is it safe? Okay, so we have a real problem with this question because there were several really big studies conducted in the early 2000s that were botched. Okay, so you probably heard about the women's health initiative study of the year 2000, so 2002, the million women study of 2003. These were two big studies that seemed to show an elevated risk of breast cancer in women who used estrogen replacement therapies. Those studies had many problems with them. We've seen some more recent reviews that have indicated other possible elevated health risks in using estrogen replacement therapy, but not of the order that was found in these studies. And then we have a review that came out just last year by Etting-Duratoll that found that there was an increased risk of breast cancer in women who use HRT, but when they actually controlled for other variables like obesity and smoking, the women who had took the HRT only actually had a lower risk than women who didn't use. Okay, so where are we at with this question? It's clearly very confused. It's not actually clear now that there is an increased risk with estrogen replacement therapy. There's really good scholarship on this question already. I'm not gonna spend too much time on it, but in short, the problems with those studies, the women were all over 60, so we know that breast cancer risk increases with age. Most women are gonna wanna use estrogen replacement therapy if they're gonna wanna use it around the time of the menopause transition, like closer to 50. So that risk factor probably isn't the same. Also, they were using oral forms of estrogen, particularly the conjugated equine estrogen. There's some new research on this that just come out this year that suggests that that particular form of ERT is more prone to breast cancer stimulus. Also, the subjects in this study were overweight and obese. So we know that that's an independent risk factor for breast cancer, and it was not at all taken into account statistically in the studies. And even from the point of view of the statistical significance in the study itself, the results they came up with didn't reach statistical significance. They themselves admitted this. So they said there was a 26% increase in the breast cancer risk, but the absolute risk, if you look at women's, gent that the World Health Organization agreed risk factor for women age 50 with no particular genetic predisposition, the risk factor is determined as 2.31%. You raise that by 26%. You're only gonna get 2.91%. So these are not very different numbers, are they? Also importantly, the authors of the Million Women study have since completely retracted the statements that they made about breast cancer risk and have provided themselves an analysis of what was wrong with their own study and with the Women's Health Initiative study. Funnily enough, in the Million Women study, the breast cancer risk was not elevated by the use of another hormone replacement therapy called tibalone, which is a synthetic steroid not used in the US, but ubiquitously in Australia and in Europe, which acts on the androgen system as well as on the estrogen system. So that's kind of interesting. A more recent study of 2012, looking at testosterone replacements for menopausal women, found that they had a reduced risk of breast cancer. So it's possible here that there is more at stake than just the absolute hormone levels or the which hormones you were taking. It could also be something to do with the ratio between testosterone and estrogen. This is something that I think we might see some more research into. Okay, so just very quickly, where can you get good information about this? One of my favorite things to recommend is this endotext book. It's written by three women who are both clinicians and researchers. So these are people who have a patient interface every day, and they are involved in research on menopausal treatments. And so this is, I think, one of the best resources for clinicians to consult. An online text gets updated every five years and really very comprehensive discussion of all the research and all the pros and cons. And these ladies, I think, like all really good clinicians dealing with women in menopaus, take the view that there is not a universal therapy appropriate for everyone. There are some women who need no hormones at all. They'll be fine without them. There are some who will need all kinds of support. So they really emphasize individual therapy. This is a really wonderful book about the history of American estrogen replacement by Elizabeth Siegel-Watson. So if you want to know more about that whole history, it really is one of the best things that's been published on it. This book, too, by Shandak Sengupta, is a beautiful study of the history of the sex steroid hormones from their intuition in the 19th century up until about 1950. This book, I think, is very interesting, too. It's quite anti-HRT, right? It really encourages women to think about going through menopause, not taking all this stuff. But I think it has a very good analysis of what is wrong with a lot of the claims that have been made about the benefits of estrogen. This one is a very pro-HRT book, also valuable, though, I think, for its takedown of the safety arguments that have been made about not taking estrogen. So if you were to look at these guys together, you'd get kind of a balanced, yeah. But unfortunately, there's no way or it's all kind of in one place. Okay, that's about it. Thanks, guys. Hi, thank you. That was interesting. And I'm curious if you looked back historically, like when you were looking at China and some of these other much, much older cultures. Was there any additional information on what was done, what could have been done, what wasn't done? Was there any context sort of pre-European history in the 1400s or 1500s on? There's very little discussion of menopause in medical sources before the 19th century in the European context. Basically, it doesn't look like, even though there were women living well beyond reproductive age in lots of different societies historically, there was not a recognized symptomatology of menopause. And there's an interesting question, like why is that, did they just not care about recording it in the scholarship? Or were women actually not bothered by it at all? And there's some evidence for the latter because when I looked at some of the late 18th century French sources, there were doctors who noticed that it seemed to be only the urban women who had these complaints. And when they went into the countryside and they asked peasant women, what happened when your mencies stopped? The women were just like, they just stopped. Did you have any symptoms? No, like what? Like I no longer have to worry about getting pregnant and I don't have to worry about the blood. And yeah, so there's some suggestion that maybe the symptomatology of which many women complain today is a product of certain modern life ways. Do you have any recommended reading on the safety or other consequences for hormone replacement in the transgender context? Now that's a really interesting question. Yeah, I think there's very little that's been published on this, but there are now some new studies that have come out and surprise, surprise, they don't agree with one another. So kind of the same thing is happening. I've seen two studies just in the last couple of years and one found an increase of all kinds of cancers in people who'd been taking estrogen over the long term and another found nothing of that kind. So I think it's probably gonna be a while before that issue gets sorted out. But yeah, I can refer a couple of papers to you. That would be great, thank you. So we know that the age of menses has gotten younger. What's happening with the age of menopause? Is there any evidence that it's changed over time? There's some evidence it's actually later. So historical sources that I've looked at tend to place it around 47. And that's kind of young by our standards. So it's more common for women to enter menopause transition after 50, but there's a lot of variation as well. So it's not clear from the historical data whether these were, they did not have an exhaustive statistical survey. And what we know from our current statistical surveys is there's quite a big range. Thank you, I enjoyed your talk. Can you speak a little bit about testosterone in women and sexual desire and all that sort of thing? Yeah, yeah. Well, one of the really big claims that was made about estrogen replacement for many years was that it increased libido. And therefore, you could hold on to your husband a lot better if you took it because you'd be able to please him. And so there was a real determination to try and find the libido-producing effects of estrogen and it's kind of not really anything there. But on the other hand, testosterone is kind of looking a bit more promising, particularly for postmenopausal women. But there have been some studies that have used like transdermal testosterone therapy in postmenopausal women to see if it increases libido and they haven't found that. On the other hand, DHEA has produced a result. So that's kind of curious. Thank you for your talk, very informative. Knowing what you know and you know so much, aside from the transitional symptoms of perimenopause and menopause, would you take HRT for the purported longer-term benefits of lower dementia, osteoporosis, all the other lifelong potential benefits? Yeah, yeah. I might just put a slide that I did not get time to go into. Because I'm still working through this list, basically. So there are many purported benefits of estrogen therapy that have been studied in the scientific literature for a long time. And some of them appear to be very robust in that they have benefit and some of them, the more research that's done, the more shaky it starts to look. So the hot flushes, there's absolutely no doubt that estrogen replacement alleviates hot flushes. It's a standout most effective therapy for that problem. The bone density thing, I think, is actually very ambiguous because there've only been a couple of studies that have honestly compared estrogen replacement to resistance training as a mechanism for increasing bone density and postmenopausal women. And most of the exercise studies on this question have been really poorly conducted. The exercise they've given the women is really lame and it's just not gonna produce that effect. But recently there have been a couple of good studies where they got women to do high impact weight-bearing exercise and found very spectacular effects on bone density that are equivalent to what you would get from estrogen replacement. So estrogen certainly will have that effect in sedentary women. But there's also some research that suggests that there's not a synergistic effect, which is what a lot of researchers were suggesting for many years that you should take estrogen and do weight-bearing exercise. But it seems like if you're doing high impact weight-bearing exercise, there's no added benefit to also taking estrogen for bone density. The other areas that I've got on this list, the more I have looked at the research, the more it looks at very unclear to me actually that estrogen is that beneficial. So the research on cognition is actually very mixed. When you say cognition, are you also including Alzheimer's or? Yeah, yeah, I'm kind of grouping it together, yeah. So the cardiovascular research also is now looking somewhat dubious. So the claims that were made about that haven't really been borne out. The sleep question, it's still very common that women use ERT for sleep, but it seems like there's only an indirect mechanism by which it's helpful, which is if you're being kept awake by hot flushes. So yeah, the estrogen is great for hot flushes. And if that's what's stopping you from sleeping, then it might help your sleep, but it does not directly impact sleep. The effects on mood were also long touted and they haven't been borne out. In fact, the androgens seem to be much more mood elevating for postmenopausal women. And libido also, the other one. So there's an indirect effect again with estrogen if you use it as a topical vaginal cream in that it does improve the vaginal dryness that can be inhibitor for some women of sexual activity postmenopause. But if that isn't the issue, it's not gonna increase your libido as much. Thank you so much. Welcome. There are several studies out there that show that men will upregulate testosterone in conjunction with exercise, particularly weight training or weight-bearing exercise involving the legs. Have there been any comparable studies on estrogen and could this explain the split between peasant and urban women and menopausal symptoms? Yeah, so estrogen, I don't know of any studies that have looked at what happens to the estrogen and they were with exercise specifically. But certainly that effect on testosterone also occurs in women. So women's testosterone is increased by resistance training. But unfortunately a lot of the studies that have looked at postmenopausal women and exercise include women who've had hysterectomy and opherectomy and have these very suppressed testosterone levels. So I think that's a really confounding problem in the research. And I suspect that it'll be a while before we have really...