The BIRTHFIT Podcast Episode 85 Featuring Dr. Irene Tobias



Lindsey: Hello, BIRTHFIT. This is Dr. Lindsey Matthews, your BIRTHFIT founder. Today, we have a live episode. That means, the conversation was recorded live. And I am talking to the lovely Dr. Irene Tobias.


Dr. Irene Tobias works with Dr. Andy Galpin down at Cal State Fullerton. If you don’t follow either of them on Instagram, go do that now. They’re doing tons of research in muscle physiology that’s probably way over my head. But they’re definitely leading the charge as far as research goes.


Dr. Irene Tobias is a PhD biochemist and an MIT alumnae, I think that’s what you say for a female, who is a part of Dr. Andy Galpin’s team, like I just mentioned. She is studying a molecule called AMPK. That’s all I really know about that but we dived into it on this episode. We also get into a little bit of training as it relates to the female cycle. We get into muscle repair, ligament repair, all things like that.


Probably nobody is surprised, there is limited, limited amount of information out there as it pertains to a young adult female, let’s say, between the ages of 16 through about 45. It’s really interesting. And I just can’t wait for you to listen to this. You’ll enjoy this. Let’s talk afterwards.


Welcome. Welcome to the BIRTHFIT podcast.


Irene: It’s great to be here.


Lindsey: Yeah. I’m sitting here. We have a live guest which we had not had in quite some time unless we were on the road and recorded without [0:02:37] [Indiscernible]. This is bringing back memories. Just a year ago. But I’m sitting here with Dr. Irene Tobias. Did I say that correctly? I’ll let her give a little intro as to who she is and what she does.


Irene: All right. I’m a post doctoral researcher. That means I finished a PhD and doing research after that. Hopefully, you’re doing more of the science that you want to do or the questions that you want to go after. Sometimes people use it as a segue into becoming a professor. In fact, that was more of the traditional route of what people did a post doc for but now especially in life sciences it’s becoming much more common to have to do that even if you want to go into industry or use it to go into other routes, maybe federal regulatory routes, all sorts of things. There’s a lot you can actually come out doing with it. But basically, you get to publish more.


But I’ve been working with Dr. Andy Galpin who a lot of people are familiar with from many different podcasts related to strength and conditioning. That’s how I got familiar with him too. I was listening to him on Barbell Shrugged and I was maybe six months out of finishing up my PhD and I was really frustrated with research. Everyone that has gone through that knows what I’m talking about. You’re like, “I hate science. Get me out of there.” Reviewer number two, all these things, when you’re trying to publish something and get out of grad school.


And then I heard him speaking to the Barbell Shrugged guys and he comes in and he’s got this science is logic going. He goes on about all this Aristotle stuff. And then I found out actually what his research was. Because I’d heard him speaking about muscle physiology. And then when I heard he actually took biopsies out of people and then you can study the muscle at the molecular level, at the cellular level, so really delve into that type of thing, and I was doing a PhD in biochemistry, so I was already studying all those proteins that you’d want to analyze.


Lindsey: Okay. So, you reached out to him. Did he reply right away?


Irene: Yeah. I think it was six minutes, ten minutes or something like that. It was just an email.


Lindsey: You got a reply right.


Irene: We took a little while last summer to actually meet up and figure out. I was traveling a lot. And then it just seemed like — I mean, I was trying to figure out what I was going to do and I had always thought I was going to go back into industry and then was sort of like, “I don’t think I want to work for a pharmaceutical company right now. I want to go work for this guy I heard on the radio. That sounds more fun.”




Lindsey: Yeah.


Irene: Yeah. It’s been wild but it’s been the right choice.


Lindsey: Did you always want to be in research or in the lab side of things?


Irene: I mean, it’s hard to say. I’ve gone through a journey of many different scientific areas and studied engineering as an undergrad for a bit. There’s so many different directions you can take on science and engineering degree. I like doing the lab work now. I like writing things up. I like figuring out what to do, where to go next, that kind of thing. But I could transition away from that at some point as well.


Lindsey: Yeah. If there’s another fork in the road.


Irene: Yeah. You never know what it will lead to.


Lindsey: So, what does life look like right now for you?


Irene: For me, I actually manage — I actually do a lot of my work from home. People don’t often think about it but science actually is a lot of writing, which I actually like that part. The part I don’t like is when you’re doing the same experiment over and over again and trying to figure or trying to troubleshoot and figure out what went wrong.


There’s also a lot of literature review to figure out what you’re doing. A lot of times you’re putting together presentations, you’re trying to go after funding, you’re writing grants. I’m helping him out with a lot of those things. But then again there’s the experimental work too which you come in and do. Yes, I could move up to Fullerton but I love my life in San Diego and I didn’t really want to move away from that. It works, actually. It’s been working for a year now.


Lindsey: That’s awesome.


Irene: Yeah.


Lindsey: What exactly are you working on any projects or experiments right now?


Irene: So, we just wrapped up a paper which I submitted about a week ago which was exciting because we’re excited about the data we got with it. It was more of a paper oriented around a new method we’re using. In his lab, he does a lot of work related to muscle fiber type. A lot of people have heard him talk about this subject. People may be familiar with slow twitch versus fast twitch muscle fibers.


You will find different proportions of them in different type of athletes. It was traditionally thought that it was genetically determined, what type of fibers you had, but it’s actually becoming a lot more apparent from lots of research in the past decades and even some of his stuff that it has a lot more to do with your training and you can change your fiber type over time. It’s pretty cool. Muscle is this what we call a tissue of plasticity, that we can change it by our actions.


Lindsey: Epigenetics.


Irene: Yeah. There’re not a lot of other tissues in your body that you have that type of control over.


Lindsey: Yeah. That’s pretty awesome.


Irene: I can’t grow more brain cells if I really put my mind to it. I mean, maybe there’s some ways we’ll figure out in the future. You can get a better idea how to grow more muscle or if you orient yourself around that or lose fat or that type of thing. It’s a very interesting tissue to study in that regard. And the fact that we can study it out of humans which is really, really rare. I mean, you can’t take biopsies of somebody’s brain.


Lindsey: Yeah, if you think about that.


Irene: No. But you can take muscle biopsies and it grows right back. You can do it before and after exercise or an acute exercise or take people initially and then have them train for a while and see how that changes.


Lindsey: How big is the biopsy usually?


Irene: Oh, it’s tiny. It’s about the size of like the head of a pencil eraser. It really isn’t that much. It seems like, yeah, but no it’s not bad.


Lindsey: So, that’s what you all are working on right now?


Irene: Yeah. The first study we wrapped up was actually a single subject study. It was really just looking at a new method we’re doing for something. Those papers are actually really useful for other investigators that, “Oh, that’s a better of way of doing this. Now, I can orient my research around that.” But it was fun because I got to use my own muscle tissue which was exciting.




Lindsey: You find out a lot about yourself.


Irene: Yeah. I mean, there’s some of that in there. But, I think, for me, it was more after five years, six years of graduate school where everything in your study is like a cell culture in a dish. If it’s human cells they have 82 chromosomes. They’re not really human anymore. They’ve been growing in a laboratory for decades now.


Lindsey: Yeah. And it’s hard to maybe relate to that.


Irene: Yeah. I mean, you can learn some basic function things for proteins. I mean, there is a lot you can do with them that you wouldn’t be able to do otherwise or you can’t do for obvious ethical reasons. And then there’s stuff you can study from mice and rats that gives you the basic idea of things. But when you get to study real humans, it’s got a whole different dimension to it. Yeah. We did that paper and now we’re starting another one with multiple subjects. We’re going to do a population of men first, trained men, because that’s the standard way of doing things.


Lindsey: She rolls her eyes.


Irene: Yes.


Lindsey: Which I’m going to ask you about in a minute.


Irene: For sure. But we also want to add a population of trained women. Because some of the questions we’re going after, the women are kind of rarely studied for a lot of reasons.


Lindsey: A while back whenever, I actually ran into Dr. Andy in person, I asked him, which basically comes from a number, I would say — I at least get one or two questions a month from women reaching out via BIRTHFIT saying, “Hey, have you studied the functional progression in postpartum women? Have you studied muscle tissue on postpartum women? Or training in pre-natal women?” I’m like, “Absolutely not.” The studies out there are so limited.


Irene: It’s very wide open, yes.


Lindsey: Then I go to him, I’m like, “Hey, can you run any of these studies?” He’s like, “You need to ask Dr. Irene about this and why.” Yeah. Can you share a little bit about why it’s so limited?


Irene: Sure. So, yeah, you’ll read a bunch of these studies, papers that are done and typically they’re almost maybe 80%, 90% of the time done in college aged men, typically recreationally active, which–


Lindsey: Can mean anything.


Irene: That can mean a lot. Or some other studies, they’ll do with diabetic patients, because there’s a lot of funding for going after that. It’s a very informative system in terms of diabetes, looking at somebody’s muscle. But the thing with the women is that there’s the uncertainty of the menstrual cycle, is the bottom line.


Lindsey: That’s what he said.


Irene: Yes. Women are complicated.


Lindsey: Yes, we are.


Irene: There’s a lot going on and scientists have, well, as I have it, as I like to say, there’s the tendency to go after the lower hanging fruit. So, the things that you don’t have to worry about controlling so many variables for that are more routine, standard, easier to publish, faster, that kind of thing, and men are the lower hanging fruit.


Lindsey: Yeah. For sure. Women are away.


Irene: In many ways, yes. It isn’t so much of a sexism thing. I mean, people could certainly read into that. But it’s more of this is the way it’s been done and we want to try and do something new but we don’t want to have to re-work all these other things.


Lindsey: Right. Or break the bank.


Irene: Yeah, yeah. But it’s still very interesting to — We can’t really understand everything about humans if we’re only studying men.


Lindsey: Yeah, one sex.


Irene: Yeah, yeah. And there’s got to be some very interesting things physiologically and related to the hormones as well that could be different about female muscle physiology than male muscle physiology. And what are some of those things that could inform women better about their training or things like fertility and related to, like you said, postpartum? It’s interesting there are — The few studies that you will see done in women typically tend to be more with post menopausal women.


Lindsey: Yeah. When they’re way far down the line.




Irene: Sure. But it makes sense with the hormone thing because now their hormones are kind of–


Lindsey: Like plateaued.


Irene: Constant. So, the variability thing. The reasonable concern is when you’re doing studies with human subjects there’s a lot of scheduling. You don’t have the humans living in the lab like mice. You actually have to work with their schedules, the investigator’s schedules, and you could imagine if you’re doing a study with women where you’re trying to normalize over the course of the menstrual cycle, whatever, 21 to 35 days or something like that, and you’re trying to say, “Okay, the women will come in day one through six.” That’s going to be really hard because everyone’s cycle is always–


Lindsey: All over the place.


Irene: Yeah. And then there’s also birth control, of course. A lot of women in their 20s and 30s are going to be on hormonal birth control. So, how does that factor in? But we want to work around those things. I mean, a lot of the — By the time it sort of the question of what you’re studying, does it even matter, the hormonal variability? If you’re just probably going after fiber type, our inclination is that it doesn’t.


But right now, we’re investigating an enzyme that’s activated by exercise. And it turns out that it’s activated by a lot of things. It’s a really interesting enzyme that’s called AMPK. It’s been somewhat tied to improving aging and some of the — Like metformin, for instance, is this drug that’s been used for decades now to treat type II diabetes. And they’ve also seen in some clinical studies that metformin was improving aging and they were tying it to that the drug actually activates this enzyme AMPK.


Lindsey: Like exercise.


Irene: Yes. And what does exercise do? It often improves aging really well. It could be — We still don’t really understand the molecular mechanisms very well of what exercise actually does and so it’s really interesting to study it from that lens. I mean, like the same thing as a lot of drugs. We still don’t understand exactly what they do. We know that they work or something like this. So, that’s a really interesting thing to go after.


But since this enzyme is very, very much involved with all sorts of signaling pathways, metabolic pathways, there’s also been some studies showing that estrogen could activate it. And again, not really in humans yet but in mice and rats and cell culture models. So, that does kind of throw a wrench into the system. It’s an interesting thing, of course, but it sort of — In my mind, if we do go after the female population, which I really want to do and we’ve got to make sure we have the money for it, of course, but I probably actually be more inclined to pick a population of women that are on the same type of birth control.


Because you do find more popular means like IUD and Mirena. It’s very popular these days. Or the NuvaRing. And then they’d be on basically a constant hormonal concentration. Hopefully, in that case, you would normalize against that. But in the future, it would also be really interesting to study this from the perspective of a natural cycle and how are these things changed throughout the month. There’ve been some studies I’ve seen that — We still don’t understand a lot about training for females.


Lindsey: Right. Because I was going to ask if — Is there anything out there that relates the cycle of a female to training or when to train and that sort of thing?


Irene: Yes. So, I’ve actually have found some interesting things in the literature. Again, very few. This is still a very wide open area and still not very well understood. But there was one study that stood out to me where they actually took women and they compared strength training more focused in the follicular phase, so that’s the first half of the cycle, from day one until ovulation essentially, versus the luteal phase, the second half of the cycle.


The hormonal patterns are very different in these two stages. Progesterone is very, very low in the first phase where then it peaks in the second phase because it’s sort of the hormone that’s all about pregnancy and maintaining pregnancy. It’s always the hope that, okay, maybe we got pregnant and let’s get ready but, no, we’re not so we’ll go back down and start over again.




Whereas estrogen peaks in the first phase and is able to trigger the ovulation response, essentially the follicle stimulating hormone, luteinizing hormone when that peaks and then that triggers that. It’s very interesting, at least to me, from perspective of hormones or so tightly regulated and they’re so precise and they’re very effective. And there’s a reason that hormonal birth control when you take it right is very effective. And then when you take it away things go back. It’s mind boggling how it works.


But in any case, the study I was mentioning, they compared focusing your strength training in one half of the cycle versus the other. And they found that the women that did more training during the follicular phase where there was more concentrated sessions during then actually got better gains out of it. And they could measure that both by the actual strength gains, by the size of the muscle, by the fibers looking at all sorts of different factors there that they could measure.


So, that was particularly interesting. Because it brings into all sorts of questions. Is it actually beneficial? If you’re very competitive female athlete–


Lindsey: Like if you’re a lifter, cross fitter, something?


Irene: Sure. I mean, would you actually even want to target doing competitions that fall on one phase of the cycle or another or do you want to — Is it advantageous to be on birth control or not? We don’t even know.


Lindsey: How will that affect your training?


Irene: Yeah. And again, this is probably for the really higher level people that are just trying to find those incremental advantages kind of things. Yeah. A lot of wide open questions there. There was another study I found that was showing on the other side, the luteal phase, that the women were recovering better after high intensity interval training, where they were looking at the spaces in between.


And some of the reviews who summarized these studies have sort of implied that the first half of your cycle might be a more of an anabolic signaling pathway. So, more towards strength and gains and building muscle. Whereas the second half may be in a more of a catabolic state. Again, in this day and age where we have a lot of women competing in cross fit where you have to train for both strength and conditioning or high intensity intervals or endurance and stuff like that, I mean, there’s a crazy idea what if you periodize your training around your period?


I mean, people could definitely experiment with that on their own. It’s certainly nothing harmful. Yeah, there’s a lot of open questions related to female physiology that we haven’t really delved into at all.


Lindsey: Yeah. And part of me thinks you are somebody — I listened to a podcast you’re on previously but somebody mentioned, it’s either you or Dr. Andy, about we don’t even know the body’s capability. So, it’s even simplify the female hormone model into this is down, this is up. That’s crazy to me. There’s probably a lot more going on that we don’t even see.


Irene: Yeah. I mean, there’s a lot that’s been known about, or much more known about testosterone relative to performance and it’s a more simple system because it’s kind of like what’s the absolute level of free testosterone? Are you high or are you low? But with women, it’s a lot more complicated because the hormones are meant to fluctuate over the course of a month and it’s more about how responsive are they. That’s kind of the better indicator of fertility health or maybe — Again, we don’t know about the performance side of things but maybe there’s part of that as well. We do know that when female athletes in the past that were in sports where they were really under pressure to have lower weight to be gymnastics or–


Lindsey: Yeah. Like running, like endurance.


Irene: High endurance. There was a lot of instances where women would — They call it in exercise science the female triad. I had no idea what that was when I first heard the term. I was like is that related to triathlon or something?




But it’s basically a trio of symptoms that these women would get, one of them being losing their period, another one becoming anorexic, all sorts of bad things that would happen. It happened very commonly in these female athletes that were very, very underweight. And one of the treatments for them was actually being put on hormonal birth control to try and get the hormones working again.


Now, it’s kind of we’re living at more of an age now where women are going more after strength sports and competing in things like weightlifting and cross fit and power lifting where they actually do want to have muscle mass.


Lindsey: Times are changing.


Irene: Times are changing. Strength is cool now for a woman. That’s pretty awesome. But now women are also fueling themselves better. I think we aren’t really seeing that pathology essentially coming across in female athletes that we’re more familiar with. Yeah, there’s a lot of interesting things relative to how the hormones act and what’s advantageous and that sort of thing.


I mean, I hear all these podcasts where there’s some expert about hormones but it’s all focused on testosterone. The really interesting ones relative to sleep deprivation and losing testosterone from that. But it’s like where’s the one about the female hormones? Who’s going to talk about that? I guess, I’ve tried to–


Lindsey: It’s got to be you.


Irene: Yeah. Learn it myself as much as — They’re very little right now.


Lindsey: So, you mentioned about the female athlete triad. There’s one book called Exercising Through Your Pregnancy which touches a little on — I mean, for us in BIRTHFIT, that’s like the best book we found as far as research goes. But it touches very little on fertility or infertility and it was related to, like what you said, lack of just weight, lack of weight more than anything and not contributing fertility issues to exercise.


Irene: Yes. That’s another very interesting area and, of course, very relevant to a lot of women and very relevant to a lot of women in their 30s that are now realizing — Women are getting pregnant or even–


Lindsey: Yeah, even their 40s.


Irene: Later. And it’s a great change in society because it’s often that women are going after careers and that’s great but biology doesn’t keep up with society. These eons of evolution that’s come now, I mean, we’ve been learning that our diet, our bodies haven’t changed based on — We’re still more inclined to behave in a way that was like our ancestor. The fertility thing, again, follows that sort of pattern. Again, it’s sort of the question of what can you do to maintain your fertility longer? What can you do to avoid infertility problems?


Lindsey: Just like exercise really affect it.


Irene: Yeah. And exercise has a huge component to it. It’s inclined to go either way.


Lindsey: Right. I could see positive and negative.


Irene: Yeah. Because on the one end, if people are obese or they’re suffering from diabetes or metabolic disorders, there’s actually probably the most common cause of female infertility is this condition called polycystic ovarian syndrome where women’s ovaries, they contain a lot of cysts. The follicles which hold the eggs are quite large and they start secreting androgens actually. There actually would be higher levels of testosterone in the women.


But the condition also is very well correlated with insulin resistance. Typically, those women also have those types of problems, metabolic problems as well. And recently it’s been looking at treating this condition by strength training, high intensity interval exercise, things to improve your insulin resistance. And then in turn with that you improve your–


Lindsey: Fertility. Your quality of life.


Irene: Your sex hormone pathway signaling as well.




So, that’s certainly very interesting. And then on the other end, there’s the, like I talked about, more related to the female triad where women have gone amenorrheic. So, essentially, they were either very, very low in body weight or it’s also been tied to low body fat percentage. Again, women have a higher body fat percentage than men typically. And that’s for certain reasons. It’s more important to have the fat actually secrete hormones that signal to your brain and it’s sort of like is this a healthy state to be pregnant or not? And if the fat reserves are too low–


It’s almost like an evolutionary mechanism that if you’re in a state where there’s abundant energy, there’s plentiful food, that sort of thing, that’s a good time to get pregnant. If you’re in a time of energy shortage or you’re on the verge of starving, that’s not really a good time to get pregnant.


Lindsey: No. Your body is going to be like, “This is a stressful situation.”


Irene: Sure. So, it’s interesting that female fertility is very much tied to energy and metabolism whereas male fertility, actually, on the other end isn’t.


Lindsey: Would they be more related to gene?


Irene: It’s unclear. I haven’t been looking into the men as much. They’re not as — Well, no. But, yeah, male and fertility is certainly a problem as well but it doesn’t actually correlate. Like men that are either overweight or men that are underweight don’t actually have a correlation with infertility like the women do in certain way. It’s kind of interesting in that regards.


Yeah, exercise is, I would say — I’d say, in most cases, it’s going to be beneficial, for sure. If you are very, very competitive female athlete and you have a low body fat percentage it’s kind of indicative of are you losing your period or not and there’s ways to get that back if you start, if you’re feeding yourself better or maybe you get a little bit of body fat percentage back and, in that case, when you’re trying to get pregnant then that works. It’s kind of, hopefully, a simpler solution.


Lindsey: We do get a lot of questions. I would say it happens more and more now, like you were saying, because it’s becoming more common for women to wait to get pregnant or to put their career or maybe freeze their eggs and then come back to it. And so especially when they — Let me stop myself and back up. One of the biggest things I hear is that women get off birth control and then have a hard time getting their period back. But that could just be women reaching out to me and that’s the population that I hear.


Irene: Sure.


Lindsey: If you know anything about that.


Irene: Yeah. I mean, I think in that case, if a woman has been on birth control for a very, very long time, she doesn’t actually have as good knowledge about what her fertility is like. That comes if you are amenorrheic, I think that’s how you say it. Those words are really — They’re horrible to spell. I can never–


Lindsey: They all sound the same.


Irene: If it’s two Rs or if it’s two Ns, I always spell it wrong. But if you’re not on any birth control and you’re having regular periods or are they regular or are they consistent, that type of thing is very informative. The best ways of actually sort of diagnostic of fertility, there’s a blood test you can get on day two or day three of a menstrual cycle. So, when your estrogen is very low and when another hormone, follicle stimulating hormone which is sort of responsible for kicking off the, maturing the follicles. So, the little sacs that hold the eggs in the ovaries.


So, a certain population of those follicles get chosen every month, about 20 or so in each ovary of say a healthy woman in the prime of fertility. And only one of those follicles out of the two ovaries gets actually chosen out of those 20 to fully mature and release away and then the rest of them all die off. They actually compete with each other for that. It’s kind of interesting.




This follicle stimulating hormone, you want to have very low at the beginning because it’s kind of indicative of what your reserve is like. As women start to get older and the feedback loops aren’t working as well or the signal is getting lost or there are fewer eggs, she’ll start secreting more follicle stimulating hormone from the brain to just continually try. And it goes on past menopause. It’s like the brain is still trying to get pregnant. That’s a good indicator. Another indicator is how low the estrogen is at that point.


Lindsey: These are blood tests people can do on their own?


Irene: Yeah. It’s kind of silly that you would need a prescription these days.


Lindsey: I know. I still sometimes do.


Irene: Yeah. But those are blood tests when you’re not on birth control that you can certainly get. Another one which you would need an ultrasound and a physician’s office is to actually look at the follicles and count them. So, do you actually have 20 in your ovaries or are you down to five, which is as you get older? That’s going to be more commonly the case. As best as you can try and do the right things health wise, there’s still the limiting factor. The eggs themselves.


Lindsey: What you’re born with.


Irene: What you’re born with. That’s a big thing that differs between us and men is that we’re born with everything and then they continually make new ones all the time and dump them out. We’re kind of stuck with the age of those eggs. That was kind of an interesting, I guess, personal story that I went into a year ago. You get frustrated in your 30s. You meet all these men who — It’s like they have a different attitude about things. It’s always like, “Well, I can always marry a younger woman.” It’s kind of the thing.

It’s a different mentality and I kind of noticed how it starts to affect different parts of your life. And a lot of women start to realize that when am I actually going to get pregnant and I’m under this ticking clock kind of thing.


Lindsey: Yeah. And do I want a family? If I do, yeah.


Irene: Sure. And when is the optimal time to do that kind of thing? And then I read about — People have always heard about freezing down their eggs and you always–


Lindsey: Yeah. I’m so glad you’re talking this.


Irene: Yeah. You’d always heard that maybe it was some new experimental not really well proven sort of thing. But I actually read into it and just recently it actually made a lot of progress scientifically. In 2012, because one of the biggest problems was the actual freezing of the eggs. The egg is a very large cell and it has a lot of water in it. And so when you freeze water you get ice crystals. And so when you thaw those you kind of think about like ice cube putting into a glass of water and you hear all these crackling noises.


In the egg, what’s going on in that state is not so good for the egg actually surviving the thaw. So, what they were able to do is they figured out a way to essentially freeze dry the eggs. They call it vitrification. Essentially, they extract all the water out of the egg when they’re freezing it down and then it loses, it doesn’t have that problem of the ice crystals essentially.


Lindsey: And then they still freeze it after that?


Irene: Yeah. They freeze it and then when they’re thawing they have a much better survival rate essentially. It’s about 80% now survival.


Lindsey: What was it before?


Irene: I’m not sure entirely.


Lindsey: Like 20%?


Irene: But the thing is like with each step of this process — I should point out this is essentially in vitro fertilization process. But you’re doing just half of the process now and then waiting until later on.


Lindsey: Mr. Right comes in.


Irene: Yes, sperm charming or whatever you want to call.


Lindsey: Sperm charming?


Irene: Or if it’s the time in your life when you actually are ready professionally, personally, all those sorts of things that you could come back to those eggs essentially and use them. And the interesting thing is that women in their 40s, their uterus still functions well if you’re in good health and that sort of thing. It’s really the eggs that are the biggest limiting factor of the whole pregnancy.




Lindsey: Got it.


Irene: So, I read about this and I read about how in response to this improving technology Apple and Facebook had actually started offering benefits to their female employees to do this. And so now that it’s starting — And now a lot of other companies have followed suit. I think a couple of the banks. I think Google maybe as well now. It’s starting to become the future because it’s clearly in these companies interest.


Lindsey: They want to keep them working.


Irene: Yeah. Or if they have a lot of women that are in their peak of their careers and their 30s and they don’t want to slow down. There was actually a lot of controversy when this got announced. I read into a bunch of articles. Because I would look on it on the outside. It’s giving women the choice. It’s kind of like another way of birth control where it’s giving you the choice through the power of that sort of thing.


Other people were interpreting it as, “Oh, the company is trying to enforce this on the women,” or imply that this is what you’re supposed to do. But I honestly don’t think they were going to fire somebody because she wasn’t going to freeze down her eggs. It just seemed a little farfetched. Again, I think the majority of the women that choose to use this are often single where they don’t actually have the choice of getting pregnant then and having maternity benefits, all that sort of thing.


In the end, the company saves money by paying for — Because later on, if you’re trying to get pregnant and you’re going through rounds and rounds of costly IVF failures, which are an incredible burden emotionally and very expensive, that sort of thing, it saves something for everyone. And being that technology, you can kind of always predict that things are going to get better with it over time. So, whatever the success rate maybe now which I should point out it’s not like a done deal or it’s not–


Lindsey: You’re not guaranteed.


Irene: You’re not guaranteed. And no doctor will actually tell that it’s going to be guaranteed. But it’s sort of a probability thing. The more you can get the better your chances are. And with improving technology, the better the probabilities that each step of the in vitro fertilization cycle, they freeze the eggs then they thaw them then a certain number get fertilized and a certain number survive that and then a certain number survive the next stage and on and on. So, there’s a lot of things that need to come into play there. I went ahead and did it a year ago. It was a fascinating process.


Lindsey: How was it?


Irene: It’s not an easy thing. It’s not like how it is for men.


Lindsey: You don’t just go in the office and spend two hours and then done.


Irene: Yeah. I’ve even heard — I read about Tim Ferriss did this with his sperm. He froze down his sperm and he has a very chapter, I think, in one of his books describing that experience. And he had a lot of the same rationale. I don’t know. Male infertility is still an issue although I would say that a big difference, I think, between men and women in the workplace these days is that the majority of men in their 40s can have kids and even to their 50s and 60s. It’s sort of something they can almost count upon. Whereas the majority of women in their 40s can’t have kids.


Lindsey: It’s not guaranteed.


Irene: Yeah. And maybe at the very beginning of their 40s but then it’s sort of — it’s a big difference and it plays out in the work force and mindset, all sorts of different things.


Lindsey: Was the process like a couple of days?


Irene: It’s a time commitment. So, the actual doping process, because you’re essentially injecting yourself with hormones and lots of different hormones. I mentioned before that follicle stimulating hormone. Normally, your body secretes that from your pituitary to your ovaries. And the idea is to mature just one follicle or maybe two, in the case that you have fraternal twins or something like that. With egg freezing, because you want to try and get all of those eggs that are in the state, there was the antral follicles. There are about 20 of them or so each month that you could mature and release an egg.




The strategy now is to mature all of them so that they could all release an egg. You go through injecting that hormone, also some luteinizing hormone, which is another hormone of the cycle. And then some other drugs that are supposed to keep you growing the eggs but not releasing them to protect you from that. There’s all sorts of intriguing complicated endocrinology that people thought about in this whole process.


And they measure them every day. You have to go in every day, get your blood checked to make sure that you’re not over stimulating the ovaries because that can be a risky condition. I mean, it is a process that isn’t entirely risk free. And then at the end you have a surgical procedure but it’s pretty much outpatient and they remove the eggs, extract them and then freeze them down essentially.


Lindsey: Do you know where your eggs are?


Irene: Yeah. They’re somewhere in La Jolla in deep freeze.


Lindsey: Wow. That’s crazy to think about it.


Irene: Yeah. It is kind of crazy to think about. The other crazy thing to think about is that they don’t even actually know how long those eggs could theoretically–


Lindsey: They’re good for?


Irene: Like you could come back maybe 150 years from now and then somebody could have your kids.


Lindsey: Wow. That’s like Jurassic Park stuff.


Irene: I know. I mean, you’re the one that owns them essentially and the clinics recommend that by the time you turn 51 if you even hadn’t decided to use them you either discard them or you donate them to somebody else. They don’t recommend keeping them, trying to get pregnant past 51.


Lindsey: At 71 years old?


Irene: No. Yeah, it was a very interesting kind of — Yeah. On one end, I really kind of look at it as, even if I never use them, it’s changed a whole lot about my mindset in the past year. That’s been very positive. A lot of women who have done this think about it kind of in the same way. It’s an empowering experience to a lot of them. Being able to set that aside and then work on your life and go about things–


Lindsey: Career wise.


Irene: Yeah, career wise or personally wise. Maybe you want to build a relationship more before you feel that pressure of having kids. It’s a liberating idea that I could have kids in my 40s and, hopefully, that will continue to be more the future. I certainly hope that it does because, on the one end, you can look at it as, well, if it’s the highly educated women that are going after their careers who are the ones that are running into this problem, do we really want them selectively eliminated from our gene pool?


Lindsey: That’s a good question.


Irene: Yeah. It’s something that I — I definitely want to follow it. I want to see where the technology goes. I want to see where the social acceptance of it goes. Because there’s still does feel like a bit of a stigma. Of course, when you do this, everybody is incredibly supportive. But there’s still a lot of women out there that feel a stigma against doing it. Whatever you can do to make that more accepted.


Lindsey: At least have the conversation.


Irene: Yeah, have the conversation. Again, I feel like things can be very tough sometimes with how women treat other women in states like this. I think it’s always been an issue between women that choose to have kids earlier and then women that are focusing on careers and women on both sides.


Lindsey: All the emotions attached.


Irene: Yeah, the emotions attached to that and women on both sides can find a way to just be not kind to women on the other side.


Lindsey: Not nice, yeah.


Irene: Okay, it’s your personal choice how you choose to live your life and it’s a great choice either way. Like a lot of things, I often feel like it’s women sabotaging themselves more often than we’d sometimes admit.




Lindsey: Yeah. Rather than building up.


Irene: Yeah, yeah, exactly.


Lindsey: So, do you know anything about — Let’s say women get pregnant via IVF and they want to start training because this is another common question I get. Can I work out? My doctor said I can’t do anything. Or I get some doctors that say don’t do anything until 12 to 15 weeks. Then I get other doctors that say do what you’ve been doing. Some of them have no idea that they’ve been doing cross fit or whatever they’ve been doing. I don’t know if you’ve checked into that at all.


Irene: Well, I can certainly say that while you’re doing the whole hormonal stimulation protocol you do not want to work out during that ten days and particularly after the ten days are over. They do put restrictions on you for exercise and it’s actually for a very good reason because your ovaries are basically growing to be the size of a cross ball. It’s remarkable that they can do that and then come back down to their regular size. It’s a very plastic physiology. But you could imagine with ovaries that are just the size of a cross ball.


Lindsey: Little uncomfortable.


Irene: Yeah. You can get bloated very uncomfortably. But then there’s also the risk of ovarian torsion, actually. Just like in men, there could be the risk of testicular torsion. That can be a very, very life threatening, fertility threatening scenario there. Again, that’s something they monitor you. They make sure that the rate that you’re stimulating the ovaries based on how much estrogen you’re producing.


Because you produce a ton of estrogen in the process too. I actually even got kind of high off of the estrogen. It turns out it has legitimate dopaminergic and serotonin signaling effects of the brain. Yes, side note there. I mean, it is really interesting how hormones are so related to your mood and so many different aspects. With women, again, it’s more complicated because there’s the two hormones, the two principal hormones. Going back to your question, sorry about that. Yeah, definitely don’t train while you’re doing the stimulation.


Lindsey: Yeah. It doesn’t sound comfortable at all.


Irene: No. I mean, it really wasn’t that bad. I think it was more after — I think it was one night that I went out to celebrate with a friend. It was after the eggs had been extracted or whatever. And it’s actually at that point, the five days after they trigger the final maturation process of your eggs that your ovaries are the largest. So, five days later after that hormone. I had gone out with a friend and I think I got this goat cheese cake which was incredibly delicious but I was incredibly bloated afterwards. When your stomach is pushing against ovaries or pushing against everything else, it’s not so — Yeah.


Lindsey: Not so comfortable.


Irene: No. Not so good. Not so good. But I was really fascinated the whole experience because I was training for a power lifting meet at that time and, obviously, I took some time off then. I kept wondering if I was going to get some testosterone increases out of it, which I did. Because testosterone is actually made through the same pathway then you convert it to estrogen in the process. If you are making a lot more estrogen you get more testosterone.


Lindsey: So, we are more complicated.


Irene: Yeah. And it’s interesting, our testosterone levels are actually, if you compare them in a direct concentration comparison to estrogen, which is sometimes difficult because they measure them in different units, but if you do the math and make the units the same, you actually have equivalent testosterone concentrations as you do estrogen concentrations.


Lindsey: As a female?


Irene: As a female. The difference with men, of course, is that your testosterone levels are about tenfold lower than a man’s normal range of testosterone.


Lindsey: Ours are?


Irene: Ours are, of course. And then the men’s estrogen levels are a lot lower than ours. So, they have a much more divergence between the two hormones where ours actually a little bit more similar.


Lindsey: How does that change — I mean, you may not know — throughout pregnancy and postpartum?




Irene: So, I do know — Again, I don’t know much about pregnancy. I’ve never been pregnant. I don’t know much about the process.


Lindsey: We could find you some test subjects, at least for muscle biopsies.


Irene: Yeah. But in pregnancy both estrogen and progesterone rise quite a bit. And, in fact, the level of estrogen I experienced during the stimulation was akin to what a pregnant woman might actually have in their blood. The main difference being that I was still very, very low progesterone level, kind of like in a normal physiology state. Whereas in pregnancy, because progesterone is like the pregnancy hormone, it’s responsible for a lot of the processes that maintain pregnancy is very, very high as well. And a lot of things have to do with the ratio of these two hormones.


Lindsey: Where is testosterone? Does it stay the same?


Irene: I’m not sure. They don’t usually check levels of testosterone in women for comparison during pregnancy but it’s — Yeah. But again, the ratio of the estrogen and progesterone can determine a lot of things relative to mood, of course, because that’s kind of where effects from PMS come from. So, at the end of your cycle, when your estrogen starts dropping a lot, and if the progesterone is still high, then you may be inclined–


Lindsey: Bigger discrepancy.


Irene: Yeah. You may be inclined to have more mood effects from that. And again, that can be variable with all sorts of different women that experience all sorts of different side effects.


Lindsey: I’m just going to keep asking you questions.


Irene: Sure, sure. I’m sorry. I kind of stray from the question sometimes.


Lindsey: What are your thoughts postpartum wise? Because there’s a huge dip in hormones, right?


Irene: Yeah, a huge dip in hormones and then, of course, problems with depression in that state as well. Again, that’s a side of things that–


Lindsey: Not studied enough?


Irene: Not studied that well. It’s something I don’t know as much about. I haven’t looked into it. It’s certainly interesting questions and it’s certainly a problem for a lot of women and it’s a really strange phenomenon because you would think that after you’ve given birth and–


Lindsey: You’re like at a high.


Irene: Yeah. You should be at a high, right? You should have all this energy to care for the kid at such a — when they really, really need you. But then why do you have that incredible dip?


Lindsey: And I usually find it’s like anywhere from four days postpartum to seven days postpartum and that’s when I’ll check in with a patient or client and I’ll be like, “How are you doing?” “Well, the first two days were easy but now it sucks.” But, yeah, it’s super interesting.


Irene: Yeah. I mean, female sex hormones are really interesting.


Lindsey: Too complicated.


Irene: I know. And a lot to understand about them. I mean, one thing that’s always fascinated me also from a performance standpoint is how, as humans, and maybe as other primates, there’s such dimorphism or difference between the performance capabilities of men and women. I mean, yes, you have women outrun a man and circumstances here and there. But on the whole, men as a whole are going to be stronger than women and that’s why we have different sport, different–


Lindsey: Weight classes.


Irene: Different weight classes and different divisions for men and women to compete. But you look at other mammalian species and that’s not so much the case. So, best example being horses because they’re the most athletic animal out there that we actually keep data on for reasons of breeding and all sorts of other things. I looked into the hormone thing with horses. I mean, I guess, first stating out that we keep the performance state on them. In humans, I think the difference between the top male mile time versus the top female mile time is about 29 seconds, 29-30 seconds.


Lindsey: And I was sure it’s under five minutes.


Irene: For horses?


Lindsey: Oh, sorry, no.


Irene: Yeah, yeah. I think the female’s time is like 4:13 or something like. Insane. And then the men did like 3:45.


Lindsey: So, what’s horses?


Irene: With horses, for running, say, a race of nine furlongs, which is about a mile and an eighth, kind of like a mid distance horse race, the top male and female times differ by two-fifths of a second.




I think this was from one of Secretariat’s races that he won and then another mare filly that won it a number of years later and they compared. It was like the same track, the same conditions, everything. Again, the stallions do tend to win more often but the fillies compete with the stallions or with the colts. What’s going on in their physiology?


With the hormones, they’re actually, in stallions, they’re way, way lower in testosterone concentrations than human males, almost about tenfold lower in a way. You could kind of think about why that is and it’s probably making sense that it’s kind of like maybe a balls to body weight ratio, would probably be my hypothesis. Seems to make sense. But then, of course, anabolic steroids can be used in horses and that can also increase their performance.


It may be that they’re more even on the testosterone signaling but there could be plenty of other reasons as well. It’s an interesting thing, I guess, thinking of like comparative physiology standpoint. But, yeah.


Lindsey: So, I’m going to shift into more muscle. We get a lot of questions about how long will it take my abs to heal? I don’t know if you’ve heard that one.


Irene: After pregnancy?


Lindsey: Yeah. Or repair muscle tissue, ligament tissue. What would you say about that?


Irene: To be honest, I have no idea.


Lindsey: The answer is still unknown.


Irene: Yeah. Or it’s not something I’ve looked into.


Lindsey: I don’t think there’s anything out there. But that is like one study that people are like, can you test how long it will take to heal my abs?


Irene: Sure, sure. One thing that Andy has looked into or has done, I think, some research with one of his collaborators on is kind of — So, within the question of you take some time off from training then you come back to it and people often find that it’s easier to get back to where they were quicker than it was when they started.


Lindsey: From ground zero?


Irene: From ground zero. And they actually found pretty plausible interesting mechanism for why that is so. So, in your muscle cells or your muscle fibers, you have tons of what they call myonuclei. So most cells only have one nucleus which controls everything. It’s got your DNA. It tells you replicate, grow this protein, shut this off, all that sort of thing. Kind of like the brain of the cell, if you want to visualize it that way.


Muscle cells are very unique is that they have tons of myonuclei. So, tons of control centers distributed throughout the fiber. And what they found is oftentimes you can increase the number of those myonuclei as you start growing the fibers. Andy gives the analogy of like expanding a business. Because if you start spreading into more territories you’re going to need more managers.


But then if you start detraining or you take some time off, maybe you got injured or got other things to focus on in life, maybe like getting pregnant, the fiber size decreases but you actually keep all the myonuclei that you started off with. The cell cease the — I don’t know. There’s a benefit in keeping all these managers around. And then when you’re ready to start growing again it makes it an easier process.


Lindsey: Wow. That is interesting.


Irene: Yeah. Again, we always think, oh, we figured out the mechanism. And then later on–


Lindsey: Something else.


Irene: Something else pops into and it ends up being more complex than we initially perceived. But it seems plausible.


Lindsey: How long would you say it takes a muscle to heal or like a biopsy to repair itself?


Irene: That’s a good question. I’ve had tons myself. They can be sore for a while. You might feel them sometimes in different stages. But again, the soreness is definitely nothing as bad as what you would experience through certain types of training or certainly would never be as bad as some of those types of [1:05:02] [Indiscernible] that we’re all familiar with.




But, I mean, it’s such a small part of the tissue that you take out that it doesn’t really affect the 0.001% of whatever you’re working with. And your muscle is always breaking itself down and building itself back up. So, it’s a mechanism. It’s a regenerative tissue. I mean, unlike other tissues in our body, cartilage being probably the worst in terms of its ability to regenerate, that we have different capacities to build back certain types of tissue but not others.


Lindsey: Yeah. It would be great if we could rebuild cartilage.


Irene: Yeah. That would be like — I don’t know. Sometimes you think about, okay, the end of your life and you get to meet your maker and you get to have a list of suggestions, handy suggestions of how to improve life in the next universe. One of them could probably be make cartilage regenerative.


Lindsey: [1:06:11] [Indiscernible].


Irene: Yeah. Make women keep their fertility longer in life.


Lindsey: Yeah. At least through their 40s. Before we get off, can you share a little bit about why it’s such a pain in the butt to do studies, funding, everything related.


Irene: Oh, yeah, every scientist’s favorite thing to bitch and moan about.


Lindsey: Right. But I don’t think people realize what a pain in the ass process it is.


Irene: Yeah, for sure. I mean, Andy and I, that’s probably our number one struggle or challenge to overcome but we’re finding a lot of new potential routes. Again, everything is sort of a potential route until you actually see the money. But for ours, a big problem is that we’re not directly studying disease. A lot of the federally available grants from the NIH, for instance, or even from other sources like the DOD always wants to fund cancer research or you want to fund diabetes research, of course, because those are two of the most costliest diseases out there. It’s pretty clear in the government’s interest to fund those sorts of studies.


But when you don’t have an immediate direct link to disease, it’s often very, very difficult to pitch those funding stints. Where on the other end, we look at it as, well, there are very, very few people studying the opposite end of the health spectrum, studying in athletes or studying people that are doing really, really well at some aspect of health or whatever be.


Lindsey: Yeah. Testing human limits, basically.


Irene: Yeah. It’s a much more intellectually stimulating subject to study, I think, as well, the best of humanity in a way. I think there’s tons of things you can learn about studying those people that you could potentially use to help other people in the future.


Lindsey: Totally. I agree.


Irene: The NIH doesn’t exactly have that or visionary thoughts process to it. That’s the struggle with federal funding. With private funding, you often run into the issue of, well, we’re the supplement company and we want you to test our supplement but what the data, they obviously have a vested interest on what the outcome of the data might be. And it may not really be what you want to study or that kind of thing.


You get caught into all sorts of problems with that but we’re also very interested in the potential for crowd funding. We actually did this a year ago. We did a small crowd funding grant campaign just to get the funds to finish building a microscope. Their collaborator, the one that does all the myonuclei, the imaging studies on muscle fibers, needed to complete that so he could run more of his studies.


It was like money that directly went to, you know, not just messing around in the lab to fund a very critical piece of equipment. But, yeah, I mean, we’re looking into other sources. There’s tons of people, I think, out there that are interested in these same questions, the capacity of studying elite athletes, learning more about human physiology from a performance spectrum, what are limits of–


Lindsey: Female physiology.


Irene: Yeah, female physiology, all those sorts of things. It’s kind of like in this day and age there starts to be more unconventional alternative approaches to things and we’re already learning that with media now.




We’re straying away from the mainstream types of media. Maybe we’ll also be able to stray away from the mainstream types of funding. So, who knows what will happen?


Lindsey: What’s like an average cost of a study?


[background conversation]


Lindsey: Do you know the average cost of funding?


Irene: It depends on what you’re doing.


Lindsey: Loads of study?


Irene: Yeah. It really does. But it gets way more expensive when you start adding in the biochemistry stuff.


Lindsey: Okay. So, where can people find you on social media?


Irene: Well, definitely, if you want to follow the science, probably Andy’s Instagram because he posts all sorts of stuff. I occasionally post a picture of me doing something fun somewhere. I do want to get more into social media and using it in the right way and connecting with people through that. I am Dr. Irene Tobias and I hope to expand it more in the future but follow Andy’s for now @drandygalpin on Instagram.


Lindsey: Thank you so much.


Irene: Thank you.


Lindsey: This is awesome. All right, BIRTHFIT listeners, I hope you enjoyed that episode. We stopped abruptly because our memory card was running out. So, if you have any questions, please do email them. We will definitely link up with Dr. Irene Tobias again in the future. We would love, love to have her back on the show. Like I said, if you don’t follow her or Andy Galpin on Instagram, go do so. They are leading the way as far as research goes.


If there’s something we can send home about this episode, it’s that research needs funding. Research needs funding so that it will happen. I get a ton of questions, emails, “Hey, can you research ligament muscle healing as it relates to the postpartum period? Or diastatis rectus abdominis healing?” This is exactly why it is so damn hard to make studies. As she mentioned, it relates to the female cycle, it relates people’s schedules. And then, ultimately, it comes down to who wants to do the funding.


So, they do a lot of work on their own and they do some crowd funding so go follow them and definitely help them out financially, if you can, in the future as far as making research happen. I hope you enjoyed this episode. And let us know if you have any questions. Ciao.

[1:13:51] End of Audio