[00:00:00] Stef: Today's guest is Stacy Sims, a VIS expert, former rower at Purdue University, an incredible performance physiologist specializing in women athletes. Stacy is the author of ROAR, a book all about how we can match our food and fitness to our unique female physiology for optimum performance, great health, and a strong body for life.

In this episode, Stacey shares with us how we can use our periods to help train and perform better specifically around fueling

[00:00:34] Stacy: we need to fuel, especially as women we know from some really good, robust research, that's come out, that women do better in a fed state.

[00:00:42] Stef: Stacey also helps us to better understand the hormonal differences between men and women, and how these differences can guide us on how to best strengthen our bodies.

[00:00:52] Stacy: at any point in the menstrual cycle, you can come and bring your a game.

[00:00:56] Stef: For women athletes, Stacey highlights the importance of fueling our bodies in tracking our menstrual cycles.

[00:01:02] Stacy: We know that you can do some nutrition interventions if you feel a bit flat. And we also know that the psychological supersedes a physiological on any given day.

[00:01:13] Stef: Paying attention to these two components of our health can help each and every athlete become more in touch with their body and improve their performance in sport. Stacy's work is truly so groundbreaking and inspiring.

We're so proud to have her as part of our vis community, as a vis expert, as she's breaking down the barriers in women's underrepresentation in sports science and research.

Welcome to the Voice and Sport Podcast, Stacey.

[00:01:39] Stacy: Thanks for having me looking forward to our conversation.

[00:01:42] Stef: Well, you are such an incredible force within the field of sports science and specifically around women athletes. So we're so excited to go deep today in some of the discussions around getting your period, what it means for your performance and training, and ultimately just learn a little bit more about you and where it all began.

So let's start with the very beginning. You grew up in many different places around the world. So how did this shape your curiosity?

[00:02:07] Stacy: Oh yeah, being in army brat going to different places across the years and being introduced to different cultures. So I spent my formative childhood years in the Netherlands and traveling all over Europe, landing from Europe, back into San Francisco, going to school inner city and just being exposed to so many different cultures, so many different ideas, the way people approached problems. And it was very interesting to see on the outside versus what was happening in the US. So having a different global perspective, even from a young age,

[00:02:42] Stef: Yeah. That's so incredible. And also so important to have that global perspective. You know, a lot of things are different, but so many things bring us together too. So, you know, also I'm curious to know how you were introduced to sport, and when you first started playing sports yourself, did you start seeing gender performance differences from the beginning? Or is this something that you noticed later?

[00:03:04] Stacy: Not from the beginning for sure. It was definitely later, but I think my first introduction to play sport was my first bike. And I realized that I could ride my bike and get away from my sister was like freedom. So the fitness that came was cycling then kind of translated into a hockey, field hockey, and running.

And then when we hit San Francisco, there was no field hockey. So I concentrated on running, and joined the cross country team, ran for my high school, ran pretty well. And then as I got to university, I didn't wanna run anymore. I didn't wanna be competitive running anymore. So I walked on to the rowing team, dropped a, a scholarship to run at Purdue and walked onto the rowing team and found teamwork there and it was great. And I think that was where the real insight came of being part of a team sport because when you're an individual sport, you're doing you're training and you're looking at how you're adapting, but you're not really comparing to someone else that you should be working with. But when you get into a team sport and you're working together for a common goal and your training is similar, you're trying to maximize adaptations. And when I got into it and got into this environment, I was sort of interested to see what the training modalities were cuz I had just transferred out of PoliSci into exercise phis so starting to learn more about exercise physiology, training protocols, and also being an athlete at university and seeing that the men and the women were training the same and we are all gearing for the same races, but there were times where it seemed the men were adapting a lot faster and recovering better than we were as lightweight women.

So I being inquisitive as I always have been, I asked those questions in the Ex-Phis . Classes, like why is this happening? And no one could gimme an answer. So then I really started going well, well where's the research. I wanna understand being that kind of person and then being told, well, we don't really research women. We just generalize for male data. We don't research women because we don't know enough about men. Or women have a menstrual cycle. So it makes it too difficult to study women. And as a female athlete taking a step back going, what the, what do you mean you don't study women and then really noticing in the text textbooks, it was always a reference to the reference, man.

And if you're looking at results or norms for VO two max or lactate threshold, you realize that it's a percentage of the men that they've just dumbed down. And when you're asking questions about it, it's like, oh yeah, we take 80% of what a max man is to apply it to women even right down to like protein recommendations are based on sedentary men. And then that is what recreational female athletes should have. So there's so many things that have been generalized and it just made me mad cuz I want things to be fair and just, I always have, and I always will. So when someone goes, well you need the same thing as that old man over there. I'm like, I don't think so because as I sit here as a young 20 something year old woman, I'm pretty sure I'm very different from that old man over there.

So then that kind of pushed forward into my master's degree where I did over-training sex differences and over-training trying to understand mood differences, immune differences, and then had time out working in the real world before I went and did my PhD.

Yeah. And so my academic career was kind of driven not kind of, it was completely selfish. I wanted answers for myself and for my teammates and to be able to tell women, these are the things you should be doing. Then I would get questions and have the availability to go into the lab to answer them. So it's kind of been that parallel of these are the questions that are being answered. I can go in and answer them and then I can disseminate it and apply it and try to get better uptake for women.

[00:07:07] Stef: So when you were in those labs and you were doing those tests, you know, and you were finding, you know, different results, like, were you dismissed or was there, was there a lot of listening to kind of what, what it was that you were finding?

[00:07:19] Stacy: Oh no, no listening. Are you kidding me? No, I have been told many times across my career that I'm not a real scientist and that these results aren't valid. You need to like put them as an outlier. And even like you have metabolism labs in undergrad where you're learning about the body, you're learning about how the body responds to exercise.

and I was one of the only fit woman who would volunteer for like running on a treadmill for two hours without any kind of fluid or food or various other kind of crazy exercise things cuz I wanted to find out more about my body, and there'd be times where my results would be so far away from what they were used to getting from men that they would blame me for not standardizing, and hindsight is that it was my menstrual cycle.

Like not on the moment or in the day, but you know, a couple months later looking back at it going, wait a second. The reason why my results were so different that day than the first time we did it is because the first time I did it was right when I was on my period. And the second time was, you know, almost a month later, so I hadn't quite gotten to that stage. So that's why it's different. But instead they would throw the results out and be like, it was your fault. You didn't standardize. Why didn't you standardize? It's like I did. I'm I'm the daughter of a Colonel in the US army. Of course I standardized

[00:08:47] Stef: I love that. Wow. Okay. So just to, for context, right? What, what year are we talking?

[00:08:56] Stacy: Oh gosh. Early

[00:08:57] Stef: Sorry to do this, but important. Okay. Early nineties. Okay. So around that time also, okay. Also President Clinton right. Was in office and that's when he actually mandated that we start using female mice in science research. And, and right before that it was all male mice. And that obviously affected like a huge amount of scientific research. And so then you kind of go to a niche, which is sports science, and here you are kind of in the nineties, the same sort of thing happening. And I guess my question is for you now, we fast forward to 2020. Has there been a lot of progress because I've seen a stat from 2014 that said estimates roughly 10 to 35% of research subjects are women athletes. So still very much the minority when we represent a much bigger population than that. So where are we in this journey of kind of getting to representation in sports, science, and research for women .

[00:10:02] Stacy: We are still very far behind. It's been really only the past four-ish years that there has been a push in sport science to look at methodology and include women properly. Up to this point, women have been tokenistic included where they're included in a study, but just in the low hormone phase or only if they're on an oral contraceptive bill for a quote steady state hormone profile, but that's not appropriate either because OCS are experimental are in their own right. And so we are like, well, you're testing the OC, you're not testing the woman. So these things are starting to come out. There have been some really good methodology papers that have recently been written, but the follow through is still in its infancy. It's good to see that there's a wave of younger scientists that are coming up that have been mentored by people like me and my colleagues. So they understand it, but it's gonna take that generation to really bring it and to be like, okay, this is how we do research on women. And I always say, if research had originated from the female environment, we wouldn't be in this place because it would just be normal to look at hormone preservations so that we would actually be able to do those correctly.

[00:11:17] Stef: So why, why the hurdles to include women in sports science? And like, if we just go all the way to all the way back, I mean, we just talked about how, like the more macro general science industry wasn't including female mice, but why is it, do you think that like we started in this space of like, not including women in sports science research to begin with, like, when you think about just like, how did we get, how did we get here?

[00:11:46] Stacy: It's a very much a cultural nuance and it all stems from what it means to be successful in sport. So if you're thinking about all the attributes of being successful and how that originated, it came from. You know the Olympics and it was just men and women were fallible and they had a menstrual cycle and they had a bleed phase and they were delicate pedals and they wouldn't be able to withstand the rigors of going through a scientific study, especially if there was physical activity involved.

And we all know that it's complete BS, but that is the cultural mentality that has shaped the way research has been done. And now we look at things like lack of female participation, and then we know that women want to participate, but now it's recruitment language or how the study is designed, so women are like, well, that's not quite for me.

It's very male oriented for talking about hypertrophy studies and all the language that goes around a strength training study. It's very masculine and it's a bit off putting unless, well, I and say to everyone, but to most women, because they're like, ah, just, it's not quite me. I don't know if I could fit into that environment.

So there's a, a very much lack of participation because of recruitment strategies, language around recruitment, and lack of awareness of how to encourage women both to participate, but actually when they are in the study, cuz we know again, language and motivation is different for women. So if we're looking at how is this study being done? Yes, we get women in, but there's a, a dropout rate. And then when they're in the study, there are a few that stay, but they still feel a little bit, eh, unless it's an all women study.

There's a couple of papers that I've reviewed and one really stuck out recently where the authors actually wrote, 'we tried to recruit women, we got three out of 36, so we're not using their data in this because we don't have enough to determine sex differences.'

They use, you know, more fluency language, but my automatic thought process is why were you so unsuccessful in recruiting women when you had a wide population at your disposal of both men and women, who, because it was military were more than likely being told they had to participate. And that was one of the comments I push back to them and they didn't have an answer why I was like, well, let's look at your recruitment stuff. Let's look at the study design, but they had no idea why they could only get three women out of 36 participants. So there's still that whole lack of understanding and awareness.

[00:14:38] Stef: Well, what advice would you have for a young girl who's maybe in the VIS community that you know is super inspired by getting into this field and wants to pursue research but knows that they're going into an underrepresented situation. What advice would you have for the young girls to, to get them involved in this research? Maybe follow a path like yours.

[00:14:58] Stacy: There are some really good mentors that, like I said, up and coming postdocs into new research positions that are really getting into some of the more male oriented areas of Thermo regulation of protein and, and muscle development. So finding someone that can be a good mentor, right. And that's kind of what VIS is all about anyway.

But also looking at some of the more liberal universities, because then you're going to have more like-minded people who are more open to what's going on, looking at how people are identifying. Are they true sex differences, biological sex differences, or are we looking into more the cultural aspect of, of gendered science?

So there's lots of really good universities that have good researchers who are now out there saying these are the things that we're doing come on in. So it's being cognant of where you want to go. And who is there to be able to help guide you.

[00:15:57] Stef: I love that. Well, and as, as women athletes, right, we have so much experience also ourselves that we can apply to the research. And we come with like a really unique point of view, so we really do wanna inspire more girls to get into this field. It's so important. And, you know, for you in your journey, right, you got your master's degree and then you kind of took a break if you will not break, but , you didn't really take a break because you went on to do Ironmans and bike racing.

And , I guess I wanna talk a little bit about that moment, you know, because you, you did, you know, you went and did the Ironman world championships at Kona, and you said that that was a definitive point for you between the hormone phases in women and how that impacts how that impacts performance. So what was it about this point and what exactly did you see in Kona that sort of, again, I guess, inspired you to continue in this field.

[00:16:50] Stacy: Yeah. So when I went to Kona for the first time I was right on the cusp of starting a PhD or contemplating starting a PhD. And part of it, I wanted to do heat or I wanted to do altitude and I knew I wanted to continue with sex differences. So training up for Kona, living in New Zealand, we had to do quite a bit of heat adaptation and acclimation, and really prepare in pouring rain and cold temperatures to be able to race well at Kona.

So we're looking at the Kiwi contingency. There was a group of us that all did very similar things with regards to getting ready for the heat. And when we got there, we all felt good, but on race day itself, there were some discrepancies in who finished with hyponatremia, so not enough blood sodium and I was one.

And when I got sorted, like I ate electrolyte tablets had to pee like a race horse, got my blood sodium up. Right. And then started going, what's going on here? And then after the race, the next day at the breakfast, talking to the other women and saying, well, how was the race? And there were two other women that had a very similar experience. And we were all in the high hormone phase. The rest of 'em were in the low hormone phase. And I was like, there's something here and I need to figure this out. So then I went back and started my PhD, looking at exercise in the heat, looking at fluid balance between menstrual cycle phases, oral contraceptive pill phases, and men versus women.

So it was that defining moment that it's like, here is something very real that is a clinical issue, but there was only three of us who all happened to be in the same hormone profile. Even though we did everything the same as the women who didn't have issues. So, yeah, that was my pivotal point to be like, okay, we gotta answer some more questions.

[00:18:44] Stef: Okay. So you went into your PhD program. What, what at the end of this, you know, what are the key physiological differences between men and women, as it relates to performance

[00:18:54] Stacy: Oh my gosh. How much time do we have

[00:18:58] Stef: All day? My friend, all day.

[00:19:00] Stacy: Okay. Well, there are a few things to consider, right? So we have actual sex differences that happen from birth. So we know that women have more type one fibers. Our hearts are smaller. Our lungs are smaller. We have different angles between the hip and the knee and the shoulder. And also in utero with the exposure of more estrogen, females are more resilient to stress.

[00:19:26] Stef: You, could you just repeat that last one? There? They.

[00:19:28] Stacy: Sure females are more resilient to stress.

[00:19:32] Stef: What, what more CEOs in the house, please? Let's go.

[00:19:37] Stacy: Yeah, even our immune system, once we start, you know, menstruating, it also allows us to be more resilient to stress in certain phases. So we have those sex differences from birth, but then around puberty, we have that epigenetic exposure or, you know, the altering exposure of estrogen progesterone for women.

And then we have testosterone for boys. So we see what happens with boys, right? They lean up, they get fitter, they get faster. Boom, they have more muscle mass. Their bone is, is stronger and bigger. They have more fast Twitch fibers. All of those things that then are deemed appropriate for being successful in sport.

We see what happens with young girls. We see, you know, a little bit more body fat coming on. We have a change in our hip to knee angle, our shoulder girdle, widens, our center of gravity changes, and we have a shift in fueling mechanisms in the fact that estrogen progesterone then have a, a counter for how we use and store carbohydrate.

It has a, a play on how we recover from exercise, so when those hormones are, are elevated, we stay in a catabolic state. We have a, a greater systemic inflammation. We have a reduced ability to use carbohydrate. So there's all of these nuances that happen around puberty that then continue all the way through our life.

So we have the sex differences that start, which are from, you know, birth. And then we have this other layer of hormonal differences. So when we look on the baseline of what's different. It also depends on sport, like empower sports, men have more fast Twitch and they have faster velocity. So they are better per se in power sports.

We look at women they're more endurant we know this just from the muscle fiber types and how we fuel. So women are, are better and catching up with men in endurance sport. And I say catching up with, because women's timeline in sport is so much shorter than what male timeline in sport is. So with technology and physiological differences, it'll be really interesting to see in the next about 10 years, how much more women can supersede men in the endurance space.

[00:21:49] Elizabeth: Thank you for listening to the Voice in Sport podcast. My name is Elizabeth Martin, a soccer player at Emory University and producer of this week's episode. If you enjoy hearing from Stacy Sims and would like to get the chance to talk to experts like her, go to voiceinsport.com/join to sign up for free membership and gain access to exclusive episodes, mentorship sessions, and other weekly content.

Don't forget to follow us on Instagram, Twitter, and TikTok, @voiceinsport. Now let's get back to the episode.

[00:22:16] Stef: Can we talk about the timeline when it comes to like when women peak in sport versus men, and is there any research that, that ties back to that? Because you know, one of the areas that we spend a lot of time with at VIS is, is running right. It's one of our largest communities here. And we often see a lot of young girls drop outta sports so early when really like their peak time can come much later.

So is that just an anomaly for the sport of running for women? Or do you see that sort of across all sports and is there a difference of like when women and men are peaking in their performance?

[00:22:53] Stacy: Yeah. So men usually peak in their early to mid twenties. Especially when we're looking at the power race sports, and then they'll start to be more endurant. Women across the board are late twenties, early thirties, especially with endurance based sport like running, you'll see a lot of the top runners will start getting a bit faster in their late twenties and then they'll really come into their own in their early thirties.

And again, it has to do with what's happening in puberty because there's so many different changes that occurring in the female body with regards to how our biomechanics are going, how our body composition is going, how are center gravity is going, but women are not taught, or I should say are not retaught how to run, how to land, how to throw with these new mechanics.

Whereas boys, their biomechanics don't really change their center of gravity doesn't change. They just get stronger. And so the training practices are different. So if we're looking at that whole time period of, from puberty to 19-20, the training methodology and the training strategies that men do allow them to keep progressing year on, year on, year on, year on year on, but the training practices that women go through doesn't stepwise increase because the body changes so much until they plateau after all of the changes around 18. And then they start implementing those training strategies, which is why they peak much later.

[00:24:20] Stef: It's so interesting, right? Because this is why fundamentally I started the Voice in Sport platform because girls are dropping outta sport around their people. Like when they're getting their puberty and, or they're developing their breasts. And they're, we, we notice that there's a drop off there, and women are dropping out faster than men at that age.

And so that's why, we're why we're doing what we're doing here at VIS, why you're a VIS expert, all these things. But it's also why I started the Voice in Sport foundation because I realized that like the, the science and like the research part of all of this needs to be wider and more distributed, we need to put way more effort into the sports science and research and women like you to fuel and fund more research because we have a lot of making up to do, like thinking about how, you know, in the nineties, we weren't even using pretty much women athletes.

And you just said earlier on that, it's really only been the last four years where you've started to see an acceleration of including women in research and having a bit more representation. But I think there's just so much education to happen in this space. And so I think what you're doing is so powerful and I hope, you know, all the young women listen to this podcast to also hear the context, you know, because we do need more women in this space as passionate as you are, because we have a lot of making up to do. So I guess, as an experience as an athlete, you know, you were an athlete in college, you were an athlete post collegiate.

You went on to get your PhD. When you come back to that athlete experience at the high level, you know, what are, what do you think are like the three most important things that you did learn about your, you know, the physiological differences when it came to performance for women?

[00:26:07] Stacy: First and foremost eat because there's so many young athletes who do not eat enough. And it's also the timing of the food. That's really important. I say that because we have this history, you know, puberty and all the body composition changes and unfortunately the cultural mentality of calories in and calories out and doing facet training and trying to make weight and all these kinds of things that really are not physiologically driven.

When we look at the physiological drive to adapt and get better for sport, we need to fuel, especially as women we know from some really good, robust research, that's come out, that women do better in a fed state. So what I mean by that is having something small before you do your morning session. So it could be a half a banana, it could be a protein, drink, something small that's gonna bring blood sugar up. The reason for that is we fuel differently than men. So we go through blood sugar quickly and then tap into our fatty acids. Whereas men will use a little blood sugar tap into their liver and their muscle glycogen and then get into fatty acids. So they have another step of carbohydrate reserve, so they can actually do the facet training.

And it's beneficial for men to do facet training, to adapt their bodies to bear more fat. But for women we're already there, we have sex differences in the muscle that make us use more free fatty acids than carbohydrate. We also have estrogen progesterone that shuttle carbohydrate away when they're elevated to grow this really nice endometrial lining after ovulation.

And we also look at some of the other nuances that come from central nervous system control and how we're fueling, so women are already at their maximum ability to burn fat. Then we come back to the training aspect. We can't do well if we aren't fueling for it, because exercise in itself is a stress and we need to fuel for that stress, so the body understands that, yes. Okay. This is a stress, but I also have fuel coming in. That's gonna allow me to adapt. So I don't have to stay in this breakdown state with elevated cortisol signaling to break down my lean mass for fuel and signaling to conserve more body fat. Because when we see women who are not eating, they tend to first lose a lot of lean mass, and then they have belly fat, regardless of what size they are.

And it's because the body's in this conservation mode. And we say, okay, if we are to look at changing body composition, trying to get you that power to weight ratio, we need to look at the fueling and taking care of the stress of exercise. And then we can manipulate things outside of that if we need to. But for the most part, when people start eating and eating well for their training, their body composition changes pretty rapidly in a positive set.

And so many women are amazed that they eat more and they lose like lose body fat, not lose performance. And it has to do with fueling and it comes from the brain. So this is where I'm gonna get a little bit more sciencey, right? So the hypothalamus is an area in the brain that controls our body temperature, controls our appetite, controls our menstrual function.

And there are two areas in the hypothalamus for women that have these neurons called kisspeptin. So kisspeptin is super important because it controls and regulates appetite as well as control and regulate our luteinizing hormone pulse, which then controls ovulation. If we get to a point where we are not eating enough, then the kisspeptin's like, Hey, wait a second. I need to start downregulating I need to start conserving.

So the kisspeptin neurons downregulate and the subsequent response is thyroid dysfunction cuz everything starts turning down. We start having a lower resting metabolic rate. We start having less of that luteinizing hormone pulse. It starts the flat line. When luteinizing hormone flat lines, we don't have ovulation.

If we don't have ovulation, we don't have estrogen progesterone. If we don't have estrogen progesterone, then we start getting into more and more endocrine dysfunction, which follows into low energy availability, relative energy deficiency in sport when then every system is affected. So food is super, super important, not only for fueling to adapt, but fueling to maintain health. That was really only one. Now the other two.

[00:30:42] Stef: I was gonna say, I was like, that was one

[00:30:46] Stacy: Now the other big two is tracking your menstrual cycle. Super, super important to track your menstrual cycle. If you are an oral contraceptive pill, understanding why you went on it first, did you go on it because you had irregular cycles when you were younger. Did you go on it cuz you have heavy menstrual bleeding? Did you go on it just for contraception use? Did you go on it because you had bad skin? These are all things that we need to reconsider use for, if you have endometriosis, PCOS then yes, there's a time and a place to be using combined oral contraceptive pill. But the thing about the oral contraceptive pill is it downregulates your natural cycle.

So you're not actually seeing what's happening with your endocrine system. The bleed period on an oral contraceptive pill is a withdrawal bleed. It's not a true bleed indicating that you have a healthy endocrine system because those hormones that you're taking have downregulated it. If we look at heavy menstrual bleeding, there's an alternative, you can look at using some drugs, right at the onset of bleeding to really control it or using an IUD neither one of those interfere with ovarian function. And the reason why I'm bringing that up is because I want girls to understand that having a natural menstrual cycle gives you so much input and insight from an objective point of view of how you are responding to training. And if you are adapting and how stressed you are, because we know that, you know, cycles go from 25 to 40 days, there's some variation in there and that's absolutely normal.

But what we're concerned about is the bleed pattern itself. So if you start to notice changes in your bleed pattern, say your normal bleed pattern might be seven days and now all of a sudden it's two or three and the flow has changed. That's the very first sign that your body's under a lot of stress.

So it's a ability to take us pause and be like, Hey, what am I not doing that I should be in order to stay healthy? Am I not getting enough sleep? Am I not fueling in and around my training well? Am I highly stressed cuz it's exams. So it's a, a way to have a stop gap before you really get into endocrine dysfunction and some significant health issues that we then see down the track as soft tissue injury, bone stress reaction, gut issues, cardiovascular issues, body weight issues, which then perpetuate girls to drop out or are sidelined from their sport.

So following and understanding your menstrual cycle gives you that objective data. The second layer on that is if you are tracking your menstrual cycle and you're using objective data to say, oh, I felt really fantastic on this training session. And then you notice that every month on the same day, you have a really fantastic training session, then you know that you can dial in your training to have a really hard day that day.

On the flip side of it, you might notice that there's a few days where you're super flat. So instead of saying, I didn't do something right, which so many women's heads go to. I didn't recover. Well, I didn't sleep well. I didn't prep. Well, what did, or I don't know what I did, but I didn't have a good training session.

And it's really coming down to physiology. It's your hormones interfering with your body's ability to really do what you need to do on that day. So if you know that, then you can say to your coach, or you can, if you're self involved in your training, you can be like, okay, on that day, I need to drop the intensity, work more on technique and mobility cuz I know the next day I'll be fine.

So it's giving you really, really good objective data to kind of bio hack and manipulate your training for your best adaptations. And then the third thing is resistance training. Doesn't matter what sport you are in, but resistance training for women is super, super important. Because we know that women do better with power-based training, especially with our muscle morphology, and when we're looking at how resistance training helps, it helps maintain a healthy metabolism. It helps with balance coordination and reduction of injuries. We also know that if you're doing a lot of resistance training work, it works to reduce belly fat and other fatty deposits that are hard to budge in women, but not in men.

So resistance training becomes a really critical aspect, especially if you're looking at power based sports or body you know, power to weight based sports with that eye of so many women are like, oh, I've gotten to this point and I'm still not changing my body composition. So I'm going to do more cardio, which we shouldn't implement that resistance training, cuz it's so beneficial, not only for performance, but also for maintaining a better body composition than if you're just endurance focused or just power focused.

[00:35:39] Stef: That's incredible. I wish I would've heard that when I was a high school athlete. And that's why we're doing this at VIS. So I, I really appreciate that level of detail. And I think where you and I are, are very aligned, too, is on this idea of like your period is your superpower, and it can become after what you just said, a natural feedback loop for you as an athlete, that gives you an incredible advantage if you're open to listening to it. and if you understand what it is you're hearing.

So I wanna dive deeper into menstruation and periods in sort of the next part of our, of our podcast year, because there is still this stigma around menstruation. And I just really wonder, you know, you've been spending a lot of time in this, in your life. So where does this, what's the historical perspective? Like how did it become taboo?

[00:36:36] Stacy: We go all the way back to written records. And we look at things like religious manifestos, doesn't matter what religion we look at, smaller tribes and most, if not, all of them have been documented by men. And in these you'll read that women are in the red tent or they're at that part of the month where they shouldn't be involved in society.

So that has kind of perpetuated this whole idea that when a woman is bleeding, she is taboo. She can't be around anybody she's dirty. And then we have different cultural aspects that come in from different. Like you have a lot of Latino culture, you have Pacific Islander culture and the non-normal Christian religions that all come in and talk about how women, when they bleed, they're bleeding out demons, or, you know, it's something that mentioned be around and it comes from the fact that men didn't understand it.

So they were trying to write a record of how to understand it. And their natural instinct was to ignore it and put women in this box that said, well, you can't come out to society because you are very weird and different at this time when you are bleeding and we don't understand it. And then as we start getting into more modern days, women were told, oh, well, you can't do anything, you're a delicate flower, you know, your body's under a lot of stress when you are at that time of the month. And you'll see it in older movies where a woman will use an excuse to get away from men or avoid a conversation because men were just like, I have no idea and I'm gonna not step there. So then when we bring it into sport, again, remember I was saying what it meant to be successful in sport or all these male attributes, so menstrual cycle was not discussed in sport because it really differentiated women from men. And we know that women have fought really, really hard to have somewhat of equality in sport. And we are not there by any means, but even the right to participate. So if they start pushing, well, I need some sanitary products on their race course, that would be an automatic eyebrow raise and be like, oh no, you can't participate. You can't do that.

So it is just kind of been tabled and no one talks about it. And the ongoing thought process is if I lose it, then I'm more like men. And so I don't have to worry about it. So that's where amenorrhea became something like, it's okay if you have amenorrhea and we know it's not okay because of all this cultural context that has built up and then transferred into sport.

And so women have really been pushed backwards in the fact that they have this misconception of being fallible and not really as strong and robust as their male counterpart to be successful in what they're trying to do, that is the historical aspect. And I can see your face and that angry face is how I feel every time I talk about it.

[00:39:38] Stef: I'm just like trying to sit here and not be like, are you, are you kidding me? But it's just to hear, to hear the historical perspective, I think is so important also for today's youth. And I, you know, for my daughter, who's, you know, eight, and as you, as you know, girls are getting their periods earlier and earlier and earlier today.

So I'm already sitting here thinking about, okay, how is my daughter gonna feel About talking about her period. And what is the impact of this long historical conversation that you just this long narrative you just described? How's that gonna impact my daughter? I know how it impacted me and in my high school and in my college with all my male coaches, I never brought it up.

I never would talk about it. I'd hide I'd, you know, all the things that you mentioned, you know, and that wasn't that long ago. So, I mean, I'm old, but I'm not that old. And I, I think like, , you know, I'm just sitting here thinking about, this is a big reason why we're doing this at Voice in Sport. It's part of why you're at our, in our community.

We have to change the narrative. And we need to do that quicker. And I guess I'm sitting here thinking like, how, how do we do that? How do we inspire women, but also the men that are the coaches of most women's teams in the United States, you know, How do we inspire them to also bring this conversation and change the narrative?

[00:41:04] Stacy: Yeah. So this is where I've been really happy to see how like tech has stepped in with your online, your, like your FitrWomans and your Wild AIs, your apps and that kind of stuff because with their coaching platforms, it takes a little bit of that tabooness away of a male coach having to approach or a young girl having to approach. It hasn't taken it completely away, but it's made some of these conversations a bit more accessible and we're also seeing more and more of the younger coaches who are male coaches coming up. And they're not so phased about talking about menstrual cycle, cuz they too are understanding that it is something that is more of a wellness check.

So girls who are having their period and they're regularly menstruating, the coach knows that they are healthy and they can keep pushing and progressing. So it's becoming more in that awareness of health metrics rather than the negativity of, you know, in the 1980s movies of girls sitting out from PE because they have their period. Right. So I'm happy to see that, but we do have a little bit more, if not, a lot more education to do.

[00:42:15] Stef: What do you think? A, a, you know, a coach that's maybe listening to this podcast could do to make a menstruation and period conversation, a regular and integral part of a team's culture in a positive way.

[00:42:27] Stacy: Yeah. So we've implemented a few things that have worked really well in development squads. So your 14 to 18 kind of range. We some have used a traffic light system where a girl comes up and she checks in. She's like I'm in the green today. And this is all based on menstrual cycle and injury risk, right. And then I'm in the orange, which means they're past ovulation. And so they can't quite do high intensity, but they're still robust, they can do really good practice, or I'm in the red, which means they're in the late luteal phase, which is right before their period starts where the body's under the highest amount of physiological stress without training.

So the coach is aware now how the coach implements things is different. So we're not telling coaches to absolutely change everything they've had on the table for practice that day. It's just being aware of where its players are. So you're not going to tell everyone we're doing our performance test today to determine the spot in the boat, or we're doing our performance spot to, or test today to determine who the traveling team is if you have most of your players in the red. Or the other thing is if you know that you have two or three players in the red, you can have your performance test, but you're not judging just that day. You're looking at a collaboration of other things that's going to make your decision, which most, most coaches should do anyway.

But the, you know, the traffic light system seems to work really well. When we have some worry about more and more girls saying I'm in the red, so they don't have to train hard, which sometimes can happen. Coaches have switched to just having the question in a wellness check where people show up for practice and they go, okay, who's injured? What happened? How is stress? When are exams? Just that general wellness check. That takes just a couple of minutes at the beginning of practice. And one of the questions that have been implemented is who's on their period or who's a few days out. Right. And they either raise or they don't, or they come up and say something, but the culture of asking those questions makes it okay for the girls to be like, Hey yeah, me, right. Because everyone's doing it. So there are different ways of approaching it. If we take it from that wellness.

[00:44:43] Stef: Super powerful. Okay. Well, let's go a little deeper into our periods here for our girls. Let's start with just, what is a normal period?

[00:44:52] Stacy: That's a hard one. Really? No, I shouldn't say that. So a normal period is more than just the bleed phase, right? So we're talking about the whole menstrual cycle, where day one is the first day of bleeding and you go all the way up to either 25 or 40 days. And then that 25 or 40th day is a day before your next period.

So what's happening there is when you start bleeding, estrogen, progesterone have come down and as they've come down, you have inherent changes in your immune system. You have inherent changes of how your body responds to recovery. It has more carbohydrate availability. So your body's really, really robust and resilient to stress at this point.

And the whole goal of that is to create a very sound environment for an egg that's gonna be ovulating or your body's ovulating or releasing the egg for pregnancy. So we lead up to about day 12 or 13. You have ovulation, after ovulation, estrogen and progesterone come up. And the reason for estrogen progesterone coming up is they, their job is to create an environment within the body that allows a really robust endometrial lining to be built and for the body not to attack and implanted implanted egg.

So our immune system changes to be more pro-inflammatory instead of the immune innate immune system that attacks pathogens. We also have progesterone that breaks down amino acid or breaks down protein for amino acids, breaks down carbohydrate for glucose and shuttles it all in to the endometrial lining. And then you have estrogen that's like, Hey, wait a second. We need to still fuel. So I'm gonna increase the amount of fatty acids that we're using and, and being available, cuz our glucose is now being used somewhere else. So in that high hormone phase, this is where we see those differences, why we have, you know, research that stops at ovulation evidently. And during that time period, we know that your ability to hit high intensity will start to diminish a little bit.

And those few days before your period actually starts, some women feel Bulletproof because their hormones have dropped quickly. Others don't until, you know, their period is actually here. So this is again why you wanna track to understand your own nuances. But this is where we wanna look at deloading, having more of the recovery aspect and taking care of our nutrition to enhance the training that we have done.

The other key point to remember is your metabolism goes up after ovulation. So all those cravings that people have and the want for more chocolate, the want for more salt, all of that kind of stuff is because your body's building tissue and your metabolism actually comes up by about 120 to 150 calories each day.

So yes, you need to eat more, preferably more carbohydrate if you are training because we can't store carbohydrate very well in the high hormone phase, but we can use it if we're eating a diet that's a little bit higher in carbohydrate. So those are the nuances. When we talk about what's happening. Across the menstrual cycle. And what is normal.

What is never discussed is the actual bleed pattern of what is normal. So if we look at what is normal from a bleed pattern, it's anywhere from two to 10 days, but if you're having continuously heavy, heavy bleeding for more than four or five days, it's termed heavy menstrual bleeding, and you can get some, some help from your doctor for that.

You don't have to be down for the count and in bed when your period starts, that that is not normal. Some cramping, discomfort, that's normal, but cramping and discomfort that is so strong that you can't get out of bed. And you're having migraines and vomiting and nausea and heavy bleeding that is not normal. And again, you can get help for that.

[00:48:45] Stef: What do you do for kind of more of like the common sort of pain, aches and pains, I guess, like you said, sort of the more normal, like stomach, pain, cramps, when you know, you're gonna be training that day, what's like a good, a good way to kind of go into that day prepared either with, by fueling or what you're doing with stretching, or even just sleep.

[00:49:08] Stacy: Sleep's super important. Taking a ibuprofen, not aspirin, but an ibuprofen can help. And one of the other things to really consider is doing a couple of 22nd high intensity efforts. So it can be three to five of them because when you do a really top end 22nd effort, it releases more growth, hormone and more anti-inflammatory responses, which then helps with the cramping and the discomfort.

And I know that it's counterintuitive cuz when a lot of women are like I'm cramping and I don't feel comfortable, the last thing in the world and they think about doing is high intensity, but this couple of short bursts could be running up some stairs, could be doing some sprints as you're warming up, that actually enhances anti-inflammatory and growth hormone responses to then help mitigate the cramping and discomfort.

[00:49:58] Stef: And what about, you know, we, we hear about this a lot, unfortunately, especially in like the more endurance sports, but like, young girls missing their periods, and this is a common issue. And I think a lot of unfortunately young women think that that's okay. So can you, can you walk us through like what to do, I guess, if you start noticing that you've missed one or two or three period, and when should you start getting worried?

[00:50:23] Stacy: Yeah. So knowing that the early, early years of having your menstrual cycle, you're still gonna be very irregular, but you can be regular in that irregularity. So when you start missing two periods, this is, it might be normal. It might not, but it's definitely an indication that you're not fueling well for your stress.

When you hit three months of no periods, that's technically hypothalamic amenorrhea. And that is definitely not good, nor is it normal. So that's why saying you track your period and you start to see these early missteps. Then you have the availability to drop the volume, moderate the intensity, eat more and see how the next cycle goes.

So it's not completely stopping everything, it's just making a very conscious effort to fuel for what you are doing. And if you have some optional days, maybe not doing the optional work or really dropping the intensity or volume of those, those optional days, because the fueling aspect and mitigating stress is so critical for maintaining that endocrine health.

And like I said, when you hit that amenorrheic state, that's when you're luteinizing, hormone has just completely flatlined and you aren't producing estrogen, you're not ovulating, you're not producing estrogen, which can then fast forward into bone injuries, soft tissue, injury, gut issues, all of those negative things that we hear about with a lot of female athletes.

[00:51:47] Stef: And what are Stacy I'm sure. I'm sure you hear so many crazy things from coaches to athletes to who knows who else, but what do you feel like are the biggest myths that you're trying to break and break down when it comes to periods and performance?

[00:52:05] Stacy: That there is negative points in the menstrual cycle where you can't perform. We know that's absolutely not true because if we are looking at any point in the menstrual cycle, you can come and bring your a game. We know that the training leading up to that event is beneficial. And that's why you're there.

We know that you can do some nutrition interventions if you feel a bit flat. And we also know that the psychological supersedes a physiological on any given day. So it's coming with the mentality that you're gonna hit your PR if you have the undercurrent of, oh gosh, it's day three of my period. And I always feel a little bit flat.

We can reset that and be like, but my hormones are the lowest, my core. Temperature's the lowest. And I have the most power, so I can really hit it hard if you're like, ah, I'm three days out from my period and I feel a bit flat, then we can be like, yep, that's all right, but we know that you can increase your carbohydrate intake.

You can use some protein before you go. And it levels that hormone playing field and takes that negative connotation out of your brain because your body is ready to go. On the other side of things is we can train according to how our menstrual cycle works, so in the low hormone phase, we can hit it hard because our, like I said, our body's really resilient to stress.

And then as we get into the ovulatory phase, we start to drop the intensity a little bit. And then those few days before the period starts, that's when we're, you know, really looking at recovery because training's different from performance we're training to stress the body, to build adaptation and get fitter for that one point in time of performance. So it's this mental idea that people have to separate training from performance.

[00:53:51] Stef: Okay. So let's pretend we are a young girl going into a competition right now. And we just got our periods this morning.

[00:53:59] Stacy: Yes.

[00:53:59] Stef: Like what's the, yeah, what's the mental, what's the mental movie we play for ourselves here and like, to get us in the right mindset, like you said, what's the mindset?

[00:54:08] Stacy: So the mindset is I have my superpower, my hormones have dropped. My body is the most resilient to stress. I can access carbohydrate. I can hit intensities. I have the ability to have more mojo and I have more power, I have more endurance, all of the things that we want to be successful. I've had many women who used to be afraid that their period would come on race day and they've listened and they have adapted.

And then they want their period to come on race day cuz they've realized that they have some of the best races. The one thing they had struggled with is if they leak. So, you know, we're in a sporting context and that can be a major issue. So now with more and more of like the period undies coming out, you have the availability of using technology to help with that instead of relying on typical fem feminine products.

[00:55:06] Stef: Yeah. I don't know if you just saw the Wimbledon, but the, and the conversation around the white outfits, did you see that some of the tennis players complaining about just how, you know, they're on their period and they have to wear white. And obviously that can be, can be pretty hard. I mean, even in the NCAA, they have some regulations around certain uniform requirements that, you know, doesn't doesn't really make us feel great.

So I think, again, a big part of about what we're trying to do at Voice in Sport is also advocate for changes like that. Right? So that there's nothing like that. That's in the way of our performance.

[00:55:44] Stacy: The New Zealand national team are the all whites and the white ferns and they have to wear white, but they can also have accents of black. So they're lobbying to have black shorts and black bottoms at all times, instead of. Some of the alternate game days. Cause I'm like, are you kidding me? We're this day and age, these are grown professional women and you're still making them more white in their, in their professional context. It's crazy. Yeah.

[00:56:10] Stef: Unbelievable. Well, that's good to know. I'll have to bring more VIS to that. okay. Well, from all of the incredible work that you've done over the, over the years, I mean, your, your background is just so amazing and we're so happy to have you as part of the Voice in Sport community as an expert, you know, what do you hope, I guess at the end of the day, you know, you, you have your PhD, your Master's you've been an athlete when you, when you really think about it and take a step back. If you could whisper something to like your younger self, just one piece of advice, what would it be for a, a young girl in sport today?

[00:56:47] Stacy: Well, if I was whispering to myself, I would tell myself to eat because of the sports that I was in and not to worry about it. But if I were to whisper something to a young girl, now I would tell her that being in sport and having her period is empowering. And it doesn't matter what other people think, because if we're in sport for ourselves and have fun, our body is really able to take on all the hits that come in if we're healthy.

[00:57:17] Stef: I love that. It's funny, like right when you started to say that I like started to get a little bit of emotional and then it just like, made me think about the emotional side of our cycles, and I think it's important to maybe just talk real quickly about this before we end, but you know, it can, it can be challenging sometimes when you're going through all of those hormonal changes in, in years where you're also going through a lot of transitions, right.

You're going from high school to college and you're, you're changing teams and your body's still changing and everything that you already mentioned about the angles between our hips and our, and our knees and all, all of this stuff. How do you best, I guess, you know, approach the emotional side that sometimes comes with the, the hormonal changes.

[00:58:04] Stacy: Yeah. And this is where again, tracking and understanding how your mental state is at different points. Cause like right before ovulation with an estrogen surge, some women feel bulletproof, but other women feel really depressed and anxious. And it is because these hormones interfere with their neurotransmitters.

But if you're aware of that, then you can do things like eat more protein because if you have more leucine, then it actually blocks some of the tryptophan getting in your brain that causes some of these, differences in our neurotransmitters and these mood responses. Taking care of yourself with sleep, sleep is so uber important with regards to regulating mood and, and being able to navigate the, the mood changes. Because if our brain is tired, then it's really hard to get out of a negative thought process and anxiety. But then the other thing that is really important is have a support network, like have your best friend.

It doesn't have to be one friend. It could be a couple of friends. It could be someone that you see and you're just chatting with. But that, that support, knowing that you're not by yourself really helps with that whole mental aspect of trying to navigate things. And, of course, that emotional overwhelmingness, when you start to have neurotransmitter changes from your hormones

[00:59:18] Stef: Love that well, on your website, you said that your vision is a world of healthy women who understand their bodies and know how to work with their unique physiology, know their periods and know that they have so much positivity around them by being a woman in sports. So, you know, as you continue your journey to shift the narrative and elevate research and science and sport, what do you hope I guess, to see one thing you'd like to see changed for the future of women's sports?

[00:59:52] Stacy: Oh, so many things, but really equality like that balance, right? Like understanding that women put as much or more effort into their sport and their passion as men. So it's everything from. You know equality and TV time, air time, to pay, to representation, to the amount of gains and things that are available. Just really, because I'm always so equality driven. So I want to see that and I want that to happen before our daughters hit that that age, right, which isn't very far. So yeah, that's what I want.

[01:00:30] Stef: Absolutely well with when we come together, I think as women in this space, we will definitely make it better for our daughters. So we so much appreciate you, Stacy. We appreciate you being part of our community and can't wait to see what you do next.

[01:00:44] Stacy: Oh, thank you. Thank you.

[01:00:46] Stef: this week's episode was produced and edited by VIS creator Elizabeth Martin, a soccer player from Emory University.

We thank Stacy for speaking with us today about the power of our periods. Often periods are looked down upon or portrayed as something that holds women athletes back. But as we learn today, some of the best indicators of our health and performance can be revealed by our menstrual cycles.

Stacey shares how to break down the different phases in our menstrual cycles and advises us on how to train accordingly. We also learn that the wellness of our bodies and of our menstrual cycles are tied into the way that we fuel our bodies and maintain our nutri. Although there can be a stigma around menstrual cycles, Stacey discusses how coaches and athletes alike can implement wellness checks in order to minimize the stigma and reshape how we talk about our periods.

Taking action to have these discussions about our bodies will only make us stronger, more well-rounded and successful athletes.

We are so thankful that Stacy shared her expertise with us today, and excited to continue working with her as a vis expert, and we look forward to seeing all the incredible work she continues to do. You can follow Stacy on Instagram at Dr. Stacy Sims.

Head to the feed on voice and sport, and filter by body or by nutrition, and spend some time diving into the incredible free resources we have here at.

If you'd like more information about tracking your period, you can take a look at our article about tracking our periods with Whoop. You can also check out the sessions page and filter by Expert like Stacy Sims or Body and sign up for one of the free or paid sessions with our Vis League or VIS experts.

Please click on the share button in this episode and send it to another athlete that you think might enjoy our conversation.

You also might wanna check out other episodes like episode number 58 period is a superpower period featuring vis expert Georgie Bruinvel's. See you next week on The Voice and Support Podcast.