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Dr. Stacy Sims: Why women need different training rules

Sports scientist Stacy Sims explains why male-data fitness backfires; cycle-aware fueling, heavier resistance work, and creatine carry women through menopause.

Dr Stacy SimsguestSteven Bartletthost
Jan 6, 20252h 4mWatch on YouTube ↗

EVERY SPOKEN WORD

  1. 0:00 – 2:09

    Intro

    1. SS

      A lot of women come with their partners to see me and say, "I don't understand. We're both doing the same training. He's leaning up and getting fitter. I'm putting weight on and getting slower." And that is because we hit puberty. We have our reproductive years. We may not have pregnancy in there. We have perimenopause, we have postmenopause, we have menstrual cycle. Each one of those is a different hormone profile that can affect the way we eat and the way we train. But no one told us this or what we can do.

    2. SB

      Until right now. Dr. Staci Sims is an exercise physiologist and nutrition scientist.

    3. NA

      Whose best-selling books and over 100 peer-reviewed studies is revolutionizing how women can optimize their health, fitness, and longevity by working with their unique physiology.

    4. SS

      We're looking at sports science research, everything from training to eating, recovery. It's based on male data, and women have been generalized to that data. Things like we see men do really well on calorie restriction and fasting, but for women, it doesn't happen that way, and we'll talk about that. And we also know that during puberty, girls' hips widen, shoulders widen, which changes our angle of the knee to the hip, what we call the Q angle, so they don't feel comfortable running or swimming or jumping. And because they're not taught this stuff, we see that by the age of 14, girls who previously were sporty, over 60% of them drop out of sport. The problem is, it's never about how we can empower women to use their physiology to their advantage.

    5. SB

      So let's change that.

    6. SS

      Let's go.

    7. SB

      As it relates to nutrition and exercise, how do I need to adapt across the menstrual cycle? What's your view on cold plunges and supplements like creatine, and what's the variance between men and women as it relates to sleep? And then let's talk about menopause, starting with perimenopause.

    8. SS

      I'm excited.

    9. SB

      The Diary of a CEO is independently fact-checked. For any studies or science mentioned in this episode, please check the show notes. This has always blown my mind a little bit. 53% of you that listen to this show regularly haven't yet subscribed to this show. So could I ask you for a favor before we start? If you like this show and you like what we do here and you wanna support us, the free simple way that you can do just that is by hitting the subscribe button. And my commitment to you is if you do that, then I'll do everything in my power, me and my team, to make sure that this show is better for you every single week. We'll listen to your feedback. We'll find the guests that you want me to speak to, and we'll continue to do what we do. Thank you so much. (upbeat music) Dr. Staci Sims.

  2. 2:09 – 9:42

    What Is the Work Stacey Does and Why Does She Do It?

    1. SB

      What is the work that you do, and why is it so important that you do it?

    2. SS

      I look at sex differences in exercise and nutrition because when we think about everything that we know for protocols, from training to eating, recovery, it's based on male data. And as a female athlete and working with women across all ages, just trying to maximize their potential, you have to lean into different data. But people aren't aware of it. So as I'm looking at what I do and trying to empower women to understand their own bodies, realize that there's a lot of research that still needs to be done. So if we think about something like caffeine, caffeine intake, right? And people are talking about how it either boosts them or not.

    3. SB

      Yeah.

    4. SS

      If we look at all the data on performance about caffeine enhancing performance, there isn't anything that's been done on women. So if we're looking at, how does that work for a woman, we have to look and say, "Okay, how much exercise have you done? Where are you using the caffeine? When are you using it?" Because we fuel differently during exercise. We go through blood sugar quickly. Caffeine clears blood sugar. So a woman is going to have to eat when she uses caffeine, whereas a man doesn't have to.

    5. SB

      You said it's based on male data. How can you quantify that? Like paint the picture for me that proves this is, is the case, for someone that might not understand the significance of what you just said.

    6. SS

      So if we're looking at sports science research, and I'll just bring it down to sports science, 'cause that's the exercise and nutrition research. If we're looking at who's around the room when we're recruiting for studies, for the most part, the language around recruitment is geared for getting men, because we're using a lot of aggressive language in sport. So it's off-putting to a lot of women. The other aspect about sports science research is there's limited funding. So then we're looking at, okay, how can we get people in that can come in for day after day or week to week? Most often it's men. When we look at what we're doing, we might be doing muscle biopsies. We might be doing blood draws. And if that's not explained in advance, it's a little off-putting to people. So when we're looking at the major recruitment strategies and the people that will say, "Yes, I'll come and do this study," it's 18-to-22-year-old college-age men. And that's just been the norm. And when we look at how studies are designed and we're looking, again, at who's in the room who's designing the studies, primarily it's men. Why? Because we see that most of the PIs on the studies and most of the, um, I guess scientists that are coming up in academia are primarily men.

    7. SB

      When did you realize this?

    8. SS

      The first time I realized it from an academic standpoint was when I was a second-year at university. And I was a participant in a metabolism lab, and I was one of the only women. And I standardized properly. I did all of the things I was supposed to do 'cause I come from a military family. I know how to follow rules. And at the end of the two weeks of experiments, they threw my results out.

    9. SB

      Why?

    10. SS

      Exactly. So I asked why. And they're like, "Well, your results don't jive with what we thought we were going to see. They don't mesh with the results that we got from the men. So they're an anomaly. So we're not gonna put them in for the, the context of talking about how carbohydrate metabolism was going." And I thought that was very strange. And I was like, "Well, I've done everything properly. How come mine are the anomaly and those guys' aren't the anomaly? How do you know that?" And they didn't have an answer for it. So that was like the sticking point for me to understand, why would my results be an anomaly when I've done exactly the same thing as what the men had done? And it came down to menstrual cycle. It came down to understanding that one week I was in a low hormone state, and then the next week, I wasn't. So when I started talking about that...This is where the, um, professor who was in charge of the metabolism lab said, like, "Well, we don't study women because they have a menstrual cycle, and we just study men because they're easier and we don't have to worry about hormone fluctuations interfering with our results." And at that point, I was like, "Excuse me? (laughs) What? What are you talking about?" So that was a defining point from an academic standpoint. But the seed had been planted two years prior when my dad, who was a colonel in the army, was like, "So what do you wanna do when you finish graduate- or when you graduate from high school?" And I said I wanted to be an Army Ranger or a Navy SEAL. And he said, "Well, you can't." And I said, "Well, why can't I?" And he said, "'Cause you're a girl." I was like, "What, well, what does that mean?" And he said, "Well, they don't accept women in, in the SEALs or the Rangers. It's a special ops, and they don't accept women." And that was the first time in my life I've ever heard that I was limited because I was a female and I didn't match what the norm was. 'Cause my whole life, I'd been playing with boys, competing against boys. I mean, like, it was just a normal, didn't matter if you were a boy or a girl, it just was what you wanted to do. And then when my dad said, "Well, you can't because you're a girl," that was the first seed that had been planted and really made me upset and said, "Well, this doesn't make sense." And then when I got to university and that happened, that was the definitive seed that just really pushed me into the whole academic and sporting career that I've led over the past 20 some years.

    11. SB

      Give me a, an overview of that career, the sort of significant milestones and the research that you've done that's fed into everything that you know today.

    12. SS

      I've been a competitive athlete most of my life. So I would, I raced bikes professionally, I did Ironman, I did XTERRA, and I'd have teammates who would ask me questions of, um, you know, like, "How am I fueling? How am I going to perform my best?" So I would take those questions into the lab. So we were looking at how do we optimally fuel, or how do we optimally, uh, acclimatize to the heat when we're at a point in our menstrual cycle where we don't have as much heat tolerance? So that we see when progesterone comes up after ovulation, our core temperature comes up, we don't have as much heat tolerance. So how do we adjust for that? So there are a lot of questions that would come through just by the nature of being surrounded by competitive athletes and being a competitive athlete. So we look at things like, we know now that when you want to do, um, acclimatization to the heat, and I bring this up because if I live in New Zealand in the wintertime and I'm trying to train for something like Kona that happens in Hawaii, and th- we max out at, uh, you know, 10 degrees Celsius in the winter, but we have to face 40 degrees Celsius to race Ironman, and we get into a sauna and we wanna accom- accommodate for that heat, we know that men can go seven days in a row and be fine to then race in the heat. But for women, depends on which phase of the menstrual cycle, and if you are going in the high hormone phase, then we say, "Okay, well you don't need a primer, you can just go in and do nine days in a row." But if you start in the low hormone phase, you actually have to go into the sauna for five minutes, come back out, and then go back in, and do that during the low hormone phase for nine days in a row. So there are different nuances in the way that your body responds to the heat and is able to accommodate for those heat shifts versus a man can just go in and accommodate for that and be ready for the race.

  3. 9:42 – 12:00

    Stacey's Academic Background

    1. SS

    2. SB

      So t- g- give me your CV.

    3. SS

      Oh, gosh. (laughs)

    4. SB

      Not the whole thing.

    5. SS

      It's (laughs) it's, uh, pretty varied. Um...

    6. SB

      What did you study?

    7. SS

      Uh, exercise physiology and metabolism.

    8. SB

      Okay.

    9. SS

      And then, um, got into ultra running when I was doing my master's at Springfield.

    10. SB

      Mm-hmm.

    11. SS

      Um, and then I started getting into more Ironman distance stuff, um, before I started my PhD.

    12. SB

      And you went to Springfield College as well?

    13. SS

      Yeah. So that was my master's.

    14. SB

      Your master's?

    15. SS

      Yeah.

    16. SB

      And what did you study in your master's?

    17. SS

      That, again, was exercise phys and metabolism.

    18. SB

      And then you did a PhD?

    19. SS

      Yep.

    20. SB

      Uh, w- what was your PhD on as well?

    21. SS

      So my PhD was looking at differences between men and women in heat performance.

    22. SB

      Okay.

    23. SS

      And how you acclimatize to it and how you hydrate for it, um, as well as looking between menstrual cycle phases and oral contraceptive pill use-

    24. SB

      Mm-hmm.

    25. SS

      ... in women. Um, and again, all of these topics were designed because of questions I had for myself or teammates had. And then from PhD, I went to Stanford and was working, um, in the high performance lab, and then moved over to do a postdoc with Marcia Stefanek, who was the PI for the Women's Health Initiative, so looking at, um, hormone replacement therapy in menopausal women-

    26. SB

      Mm-hmm.

    27. SS

      ... but also looking at exercise as a cohort to that. And I had another hand in the high performance, um, research in human biology, so I would mesh human performance with public health.

    28. SB

      Mm-hmm.

    29. SS

      And then that transcend into a lot of the stuff that I do now, looking at what can we do taking some of the ideas from high performance and apply it to general population, and how does that improve people's longevity, well-being, but also for those who are trying to be parents, who have a high performing job, who want to do well in their age group race, whatever it is? How can we maximize some of the things we know from high performance with regards to sleep, heat, cold, and apply that to a person who's just trying to get everything done-

    30. SB

      Hmm.

  4. 12:00 – 14:25

    Main Physiological Differences Between Men and Women

    1. SS

    2. SB

      And you've authored more than 100 peer-reviewed studies on exercise physiology?

    3. SS

      Yeah.

    4. SB

      And you're a research scientist at a university in New Zealand?

    5. SS

      ...I am a research scientist at AUT, and it's where most of my PhD students are, and we have a women's health program. And then, I also have an adjunct with the lifestyle medicine, um, at Stanford. So that's where a lot of the public health research comes in.

    6. SB

      When we talk about the, the differences between men and women-

    7. SS

      Mm-hmm.

    8. SB

      ...what exactly are those differences? Is it just the menstrual cycle that causes these differences, or is there other physiological differences that we need to understand in order to understand the subjects we're gonna talk about today around exercise, nutrition, and the variances between men and women there?

    9. SS

      There are sex differences in utero. I mean, when we look at, uh, at-

    10. SB

      What does that mean?

    11. SS

      So, the sex differences when the baby's developing.

    12. SB

      Okay.

    13. SS

      So we look at stress, and the mom under stress, we see that there's a higher incidence of a miscarriage if it's a developing boy fetus than a girl fetus, and it has to do with XX versus XY. Then after birth, we see that there's relatively little sex difference that is apparent until the onset of puberty. But when we're looking at the sex differences that aren't that apparent, there are there. We see that there's a sex difference in what we call muscle morphologies. That means that men are born with more fast twitch fibers, so they have more anaerobic capacity as they get older. They have more ability to produce power. We see that, um, girls are born with more more endurant-type fibers, so this means they have more mitochondria for oxygen consumption, and oxidative stress, and being able to go long and slow. Then when we get to the onset of puberty, we see an expansion of these sex differences with the exposure of the sex hormones. So what we're seeing is now the boys are getting leaner, they're getting faster, they're getting more aggressive, but girls' bodies completely change, because center of gravity drops from the chest down to the lower abdomen area because their hips widen, and their hips widen because, you know, being XX, they have to then accommodate for getting pregnant and eventually having a baby from a biological standpoint. Hips widen, shoulders widen. This changes the, um, angle of the knee to the hip, so we then have a... Yep.

  5. 14:25 – 16:55

    Q-Angle

    1. SS

    2. SB

      S- so for anyone listening, this is, there's a image I have here which I'll put on the screen, and I'll also link below, and it's called the Q-angle.

    3. SS

      The Q-angle, yes.

    4. SB

      Which is like the angle of my knee to hip.

    5. SS

      Yeah.

    6. SB

      And it's showing that women's Q-angle, basically like the shape of the gap between your leg, is- is it roughly 15 degrees? What is it? Do you know?

    7. SS

      Yeah. Yeah.

    8. SB

      Roughly 15?

    9. SS

      And i- and so when we're looking at girls whose bodies are changing, we see that by the age of 14, girls who previously were sporty, over 60% of them drop out of sport, because they're not taught that their bodies are changing so they don't feel comfortable running, or swimming, or jumping, or landing. Because they have a new, um, Q-angle, they become quad dominant, their center of gravity is different, their shoulders are wider, so they don't feel comfortable running 'cause their whole running mechanics change. So, you know, when we're looking at girls who are eight, they can keep up with the boys, right? Their bodies haven't quite started changing yet. By the time they're 10, they're starting to see a discrepancy. And I say that 'cause my daughter's now 12, and I've seen it over the course of the elementary school years, where they used to be on par with the boys playing soccer and rugby and stuff on the field, and then you start seeing a morph where the boys are becoming more aggressive and they're kicking the balls faster and running faster, and the girls are starting to develop a little bit more, getting a little bit more body fat, feeling a little bit more comfortable running. They can't do the monkey bars anymore because their center of gravity is lower, so they can't get up and do the monkey park bars as well. But no one explains this to them. So then when we see this discrepancy of being sporty, not sporty, we see, um, you know, the changes in body composition, and all of this is in those early stages of the teen years, which is another knock because we also have brain changes, where girls become more, um, self-aware and boys don't. They're like, "Okay, you know what? You pissed me off. I'm gonna beat you up and we're gonna get on with it." But girls are very self-aware and they hold things to themselves in a more negative fashion, and this creates a lot of mood changes, and this also creates a feeling of- of- of negative body positivity, so they don't feel that comfortable with how they look or who they are, and society doesn't help that either. So this all perpetuates in a sociocultural as well as a biological change-

    10. SB

      Mm-hmm.

    11. SS

      ...with regards to exercise.

  6. 16:55 – 17:38

    Fat Differences in Men and Women

    1. SB

      And as it relates to... We'll talk about the Q-angle a little bit more in a second when we talk about exercise, but the, as it relates to the other changes, um, fat-

    2. SS

      Mm-hmm.

    3. SB

      ...differences in men and women.

    4. SS

      Yeah. So if we see essential fat for men is around 4 to 8%, so that means what we need for our nerves and just survival.

    5. SB

      Okay.

    6. SS

      For women, essential fat is around 12%.

    7. SB

      Okay.

    8. SS

      So this is for nerves and- and s- looking around our central organs to survive. We look at body composition itself, we see that women tend to sit around 20% as a normal healthy individual, although the data's changed over the years, um, and men sit around 15%.

  7. 17:38 – 19:00

    Heart Differences in Men and Women

    1. SS

    2. SB

      And what about the heart? How is the heart different in men and women?

    3. SS

      So women have smaller heart and lungs-

    4. SB

      Yeah.

    5. SS

      ...relative to, relative body size to men. We also have less hemoglobin, so that means our oxygen-carrying capacity is lower. Uh, 'cause if we are looking at our red cells, and we have four different what we call heme molecules in a red cell and each one carries oxygen, our red cell count is lower as compared to men because the red cell count is driven by testosterone. So men have, uh, around 100% more-... um, aromatized testosterone, as compared to women. So this increases the carrying capacity of oxygen, which means it goes to the muscles, can deliver more fuel to the muscles to be able to contract better, have more power and more strength.

    6. SB

      Does that mean women breathe more-

    7. SS

      Not that they breathe-

    8. SB

      ... when they're exercising the same?

    9. SS

      N- not that they breathe more. When we're talking about oxygen-carrying capacity, this is the amount that you're taking into the lungs, how it transfers to the red cells to then be able to go to the working muscles to give the muscles the available fuel to do a contraction. So it's not a respiratory rate, it's the ability for you to breathe in and how fast that can be conducted to the muscle. But-

    10. SB

      So

  8. 19:00 – 20:10

    Lung Differences in Men and Women

    1. SB

      there's gonna be an impact on endurance, then.

    2. SS

      It's more of a-

    3. SB

      Or-

    4. SS

      ... power and speed factor.

    5. SB

      S- okay. Okay, okay. 'Cause the speed in which the oxygen can get to the muscles is what's being impacted.

    6. SS

      Yeah.

    7. SB

      And the volume of oxygen that can get to the muscles.

    8. SS

      Yep.

    9. SB

      Okay, fine. And then you said the lungs are s- sort- sorted, uh, I read 25 to 30% smaller than a man's lungs-

    10. SS

      Mm-hmm.

    11. SB

      ... typically.

    12. SS

      Yeah.

    13. SB

      And what's the impact of that as it relates to exercise?

    14. SS

      So when we're looking at, uh, um, I guess world records, right, that have been kept, and we see there's a gender gap there.

    15. SB

      Mm-hmm.

    16. SS

      And this is slowly closing in the endurance world, but that has to do with muscle morphology with regards to being able to go long and slow.

    17. SB

      Mm-hmm.

    18. SS

      When we're looking at the sprint capacity, where we have to have a quick transference of oxygen and a quick muscle contraction, that gap isn't closing. And that is because we have smaller lungs, smaller heart. We have less blood volume, we have less red cells. So the overall capacity for quickly developing power and speed is at a smaller, um, I guess it's a limited capacity in women versus men.

  9. 20:10 – 20:38

    Muscle-Building Capacities in Men vs. Women

    1. SS

    2. SB

      And in your book, Raw, on page four, in the opening of the book, you talk about how women are 52% as strong as men in their upper bodies and 66% as strong as they are in their lower bodies, but when women train, they can become 70 to 80% as strong as men.

    3. SS

      Mm-hmm. So when we're looking at resistance training itself, we see that women, relative to men, can accommodate and develop muscle just as well as men in the lower body, but upper body not so much.

  10. 20:38 – 21:59

    ACL Injuries

    1. SS

    2. SB

      Okay. Um, we talked about this Q angle thing.

    3. SS

      Yeah.

    4. SB

      One of the things that I've, I'm really fascinated by is there's been a big conversation recently around ACL injuries in sport.

    5. SS

      Yeah.

    6. SB

      And from reading your work, it seems that, and just doing some research online, it seems that this increase in women getting ACL injuries links somewhat to this Q angle situation, which again is the... I don't know how to explain it for someone that is listening on audio and can't see. But I will link it in the description. So I highly recommend you look at this picture, 'cause th- the minute you see it, it makes a ton of sense. But it's essentially like, uh, and this is me probably butchering it.

    7. SS

      Yeah.

    8. SB

      As a man, because my hips don't widen, my legs are effectively quite straight.

    9. SS

      Yep.

    10. SB

      So from my hip down to my toes, it's quite straight, which means that I'm gonna be more sturdy. Say if I jump up in the air, when I land, this, I know this 'cause my dad's an engineer, the center of gravity being straight means that I'm less likely to get injured. But if you're... Is that right?

    11. SS

      Yeah, 'cause your forces are going to be in a more linear fashion, so you have more, um, even distribution of the force through the knee.

    12. SB

      Mm-hmm.

    13. SS

      But for women, as you're gonna describe, our hips are wider, so we have more of an angle to the knee, and the forces aren't distributed evenly when we land. So when we look at that, as well as the quad dominance that develops

  11. 21:59 – 22:53

    What Is Quad Dominance?

    1. SS

      for women, because-

    2. SB

      What's quad dominance?

    3. SS

      So that means that we use our, um, th- front muscles of our legs, our quads, a lot more than our hamstrings, our posterior chain. So we don't use our glutes and our hamstrings by default, um, as well as men do. So we're being pulled forward more, and we li- we put more emphasis on the front of our body.

    4. SB

      Mm-hmm.

    5. SS

      Um, because those tend to take, the, the quads tend to take the bulk of the muscle work that we're trying to do, unless we're really trying to train hamstrings and glutes to fire, which isn't the default for women's bodies, because center of gravity, again, is lower, and you tend to lean forward. So when we're looking at ACL injury, again it comes down to, one, training stress, two, mechanics. And if we're not taught again how to land, how to run, how to jump with the new angles, it predisposes people to severe ACL injury.

  12. 22:53 – 25:11

    How Much More Likely Are Women to Get ACL Injuries?

    1. SS

    2. SB

      And how much more likely is a woman to have an ACL injury than a man?

    3. SS

      It is a higher rate, but the thing about the research is that there hasn't been a direct comparison, because we hear incidentally that women tear their ACL. And so we see a lot of observational studies that women have torn their ACL. And we have lots of retrospective studies that are going back to, oh, where are we in our menstrual cycle when we tore ACL? But there hasn't been a definitive comparison between men and women. If we were to look at the current research, we see a three to four to one ratio of ACL tears of women versus men.

    4. SB

      S- three to four, so-

    5. SS

      So either three to one or four to one, depending on the research that you look. So th- three women for every one man, or four women for every one man.

    6. SB

      Okay, so a 300% difference.

    7. SS

      Yeah.

    8. SB

      Okay. So interesting. I never, absolutely never knew that. And in fact, it wasn't until I was looking through your work that I, I'd seen, um... I went and did some research, and there's a big conversation online, a lot of, sort of, new- news coverage around women's football, because it's-

    9. SS

      Yeah.

    10. SB

      ... I think it's the fastest-growing sport in the world.

    11. SS

      Yep.

    12. SB

      But I read that this, the probability that a woman tears her ACL muscle is significantly, like, hundreds of percent more likely than a man because of this, in part because of this Q angle.

    13. SS

      In professional sport, it's not as much as when we're looking at recreational sport. 'Cause when we're getting into professional sport, we have specific warmups, especially for football....um, put out by FIFA to prevent ACL tear-

    14. SB

      Right.

    15. SS

      ...to make sure that you are actually properly warmed up and engaging the right muscles and learning how to stop pivot because it's a, it's a, uh, mechanism in action usually is a twisting angle. But if we're looking at more age group or grassroots sports, because people aren't aware of this cue angle, they aren't aware of the quad dominance, women haven't been taught again how to work with these new mechanics. Then we're seeing a greater incidence of ACL tear.

    16. SB

      30 female football players missed Women's World Cup in 2023 due to ACL injuries, including, in the UK, Lioness Beth Mead and Leah Williamson.

    17. SS

      Mm-hmm.

    18. SB

      Um, which is staggering to me.

  13. 25:11 – 27:51

    ACL Injury Prevention in Women

    1. SB

    2. SS

      Yeah. It's very high incidents, yeah.

    3. SB

      So is there something that can be done if you're a woman that's exercising, that's doing things like jumping and running and sprinting and the fast sort of twitch s- uh, sports, is there something you can do to avoid having an ACL injury?

    4. SS

      It's all about being strong. So if we're looking at how, what is the biggest thing for ACL prevention, and I'll bring in one of my PhD students that's graduated, looked at, um, ACL rehab after surgery. And it comes down to the definitive difference between quad and hamstring strength. So if we're looking at improving the, um, strength capacity of the hamstrings, then it offsets some of the default strength that the quads are taking. So if we're able to balance it from being front loaded to being more even loaded, it comes down to, you know how we were talking about distribution of forces through the knee, with men being more linear and women having an angle? Well, if we're able to take that angle and we can evenly distribute the load between the muscles of the hamstring and the quad, so the front and the back-

    5. SB

      Yeah.

    6. SS

      ...then it pulls the forces more centrally.

    7. SB

      Okay.

    8. SS

      Which reduces the stress of one point of contact.

    9. SB

      Got you.

    10. SS

      So if we're developing the strength through the whole posterior chain, we're looking at glutes, we're looking at hamstrings, we're doing a lot of calf work, and we can develop that whole posterior part, it reduces the incidence of being pulled in one direction and the misalignment of forces. The other is the cutting motion, more we're looking at- at, um, lateral movement. So a lot of times when we're looking at warmups and you're observing on, like, kids' sports, there's not a lot of lateral development. So if we're looking at- at, um, prevent- prevention of ACL tear, we have to work a lot of the explosive lateral movements, as well as jumping and single-length- single-leg jumping. And these are things that aren't really done in grassroots, but as we start to get more into professional sport, it's becoming more and more apparent that we have to do specific mechanism of injury prevention. So they're looking at the sport. We're a football player, we have a high incidence of ACL potential, so we have to really develop our posterior chain and we have to work on our power for our lateral movements, our step and our jump. Um, so this is part of what FIFA's put in for the warmup because there is such a draw, and as you were saying, that 33 women in the World Cup tore their ACL. Part of it is loading, part of it is a little bit maybe overtrain before they go into the World Cup, but a lot of it has to do with, um, this imbalance between the muscles, and now having to address it.

  14. 27:51 – 32:51

    Does Science View Women as Smaller Versions of Men?

    1. SB

      Did science just look at women as a different version of men?

    2. SS

      Oh.

    3. SB

      Like, d- sorry, did they just look at women as like a-

    4. SS

      Smaller version of men?

    5. SB

      Is that what, how they looked?

    6. SS

      Yeah, for the most part. 'Cause I mean, a lot of the stuff when I was going through school and n- even now, textbooks. So I was standing in the metro in DC, uh, a few months ago and there was a young girl who has just gotten into exercise physiology and I overheard a conversation, and she was talking about some of the experiments that they were doing, but it never, she never talked about, like, we have to make, uh, you know, we're doing women-specific, we're doing men-specific, and I asked her, I was like, "Has anyone, uh, you know, talked to you about how women's bodies are different than men's from angles and muscle morphology?" And she's like, "No, what are you talking about?" I was like, "This is the second year in ex phys now, and if you look at the textbooks, it's still a representation of men in the textbook with regards to images. You have him or they, you never have her. They might have a very small section in there about the female athlete, but usually it's about the female athlete and anemia or relative energy deficiency in sport. It's never about how we can empower women to use their bodies and their physiology to their advantage." And it's what, almost 2025 now.

    7. SB

      Is there any element of it of people being too scared to talk about differences in physiology amongst men and women?

    8. SS

      I don't think so. I mean, I always explain it from historical perspective. When we're looking at the history and when we started seeing the modernization of medici- medicine, prior to the modernization of medicine, it used to be women who were the caretakers. If you're thinking about, you get sick, you go, and someone has an herbal remedy for you. But when we started medicalizing and becoming more nuanced in the medical education, women were excluded. So when we start looking at- at the origins of medicine and who was in the room, it was men. When we start looking at the origins of science and science development, it was men. So all the scientific experiments and everything have always been a default to men. We look at AI now, and they're learning from algorithms based on male data. So even now, healthcare is still heavily male oriented. So when we start looking at why women haven't been included or why women have been generalized to male data, it's just been the nature of how things have developed. Now that we're aware of it and now we have more research money coming in to women's health, we're starting to see a change.... and part of the two definitive moments in healthcare research that really invoked this change. One was when we started seeing a lot of incidences with Ambien and the dosage of medicines, where women were getting into a lot of accidents, car accidents after they'd taken Ambien 'cause it was still in their system the next morning.

    9. SB

      What's Ambien?

    10. SS

      It's a sleep aid.

    11. SB

      Okay.

    12. SS

      It's a, a prescription strength sleep aid. So then people are like, "Whoa. What's going on here?" Oh, the dosage for a 180-pound man is the same as a 120-pound woman, and we also know that there's differences in body composition and metabolism. So, a, a 180-pound man can take this dose and be fine in the morning, but a 120-pound woman can't take that same dose and be fine in the morning. And then we have COVID and the outcomes of, um, long COVID and the differences between the sexes with regards to women ended up with more long COVID, men ended up dying. So then in, during the COVID time period, people were like, "Whoa, there's sex differences in the outcomes of this disease. We have to really start looking at that." So there are slow things that are really impactful on society that now people are starting to step and say, "Wait, we have to really look at women as women, and we have to look at men as men."

    13. SB

      And is there an element of hormones impacting injury at all?

    14. SS

      There's always an inci- uh, uh, an impact of hormones. When we're looking at the overlay of hormones and sex hormones and then the protocols that have been developed, they don't take into account estrogen, progesterone, and to some extent testosterone. So if we're looking at injury and the way that estrogen makes more, um, laxative ligaments, so that means that our ligaments become more lax when estrogen comes up, which is why people assume that around ovulation is when people will have more ACL tears. It's not, because we also see that progesterone comes in and can have a different effect on the tendons. But that isn't accounted for in a lot of, of the protocols that are out there for training and prevention of overtraining. We see that when we're looking at male and testosterone, there tends to be the more testosterone, the better for developing muscle and recovery, but that's not necessarily true either. So there's nuances in the sociocultural idea around sex hormones that also impact on our actual guidelines and protocols.

  15. 32:51 – 35:54

    Differences in Weight Loss Advice for Men and Women

    1. SS

    2. SB

      If a man and a woman came to you and said, "I wanna lose weight."

    3. SS

      Mm-hmm.

    4. SB

      They said, "I'm 200 pounds, um, and I'd like to lose some weight." Would you give them different advice on what to do?

    5. SS

      Absolutely. Absolutely would. And it comes down to a lot of p- uh, we see, see this on social media all the time, calories in, calories out, right? So when we're looking at calories in, calories out, that idea of that algorithm can work well in men, and the reason for that is the hypothalamus. So if we're looking at the hypothalamus, which is an area in the brain that controls appetite and also controls our endocrine system. So for men, w- they don't have as many of what we call our kisspeptin neurons activated. So this is, uh, neurons that are responsible for when we have nutrients coming in, they fire. They're like, "Yeah, okay, we got enough nutrition coming in that we can now accommodate for developing muscle and losing body fat." For women, we have more areas that are very sensitive.

    6. SB

      Sensitive to?

    7. SS

      To nutrient density. So when I say this, when we're talking about, uh, four grams of carbohydrate that come in, and say they're carbohydrate from fruit and veg, not from ultra-processed stuff. Those four grams of carb will affect the bodies differently between being a man and a woman. For a man, those four grams of carb coming in primarily will go blood sugar and then be stored as liver or muscle glycogen. For women, it's blood sugar. It doesn't get stored, because for women, in order to store muscle, um, and liver glycogen, you have to have an activation of, uh, some enzymes from the liver as well as some enzymes within the skeletal muscle itself to say, "Yeah, okay, we wanna store this. We don't wanna circulate it." So then we start looking at how the brain is perceiving that. So if the brain is saying, "Yeah, we can store this because there's still enough muscle tissue around, there's still enough blood glucose that we can keep going and we can survive the day." But for women, it sits there, the blood glucose sits there, and when it starts being used, the hypothalamus is like, "Okay, where's the extra food that's coming in so we can keep going and countering the stress that's coming in?" And the best way from a numbers perspective to look at it is when we are looking at calorie, baseline calorie intake just to exist and not get into any kind of endocrine or hormone dysfunction and appetite dysfunction, for men it's 15 calories per kilogram of fat-free mass. For women, it's 30. So we start to see men do really well on things like fasted training. We see men do really well on calorie restriction, because the hypothalamus is not as sensitive to lower calorie intake or to low carb intake or to high protein and, um, high fat intake. But for women, because the hypothalamus has more areas that are sensitive to nutrient density.

    8. SB

      What does

  16. 35:54 – 42:36

    What Is the Hypothalamus?

    1. SB

      that mean? Sorry, I'm not even sure what the hypothalamus is.

    2. SS

      So the hypothalamus is an area in the brain.

    3. SB

      Yeah.

    4. SS

      And it's just sensing. So you have blood that circulates to the brain. It senses temperature, how hot your, your blood is, right?

    5. SB

      Oh, okay, like the thermostat or something of the body.

    6. SS

      Yeah.

    7. SB

      Okay.

    8. SS

      So it's, yeah, it is a thermostat. It's the appetite control center. It's how your body responds to salt, how your body responds to protein, carbohydrate. Do I need more? N- do I need less? So it's, it's like the control center for the most part.So for women who come in and they're doing fasted training, the hypothalamus is like, "Wait a second, we don't have any blood sugar. We don't have enough carbohydrate to actually do this kind of training. So what I'm gonna do is I'm gonna create a little bit of, uh, dysfunction here, and I'm gonna start down-turning all the other systems that need the same kinda fuel, because I don't have enough just to do these muscle contractions."

    9. SB

      So that means you could end up losing muscle?

    10. SS

      Absolutely. So if a woman comes to me and is like, "I wanna lose weight, and I've been doing fasted training. I get up. I have a black coffee. I go to the gym. I do my lifting. I do some of my cardio."

    11. SB

      Which is my girlfriend does exactly that.

    12. SS

      "And then I'm not that hungry 'cause I did a hard workout at the gym. I might have a protein recovery shake, and then I'll hold off eating my first meal until noon," I always turn to them and go, "Well, why did you go to the gym? Because all you've effectively done is burn through your lean mass. 'Cause your body needs to have some fuel, and the first thing that goes is lean mass, 'cause it's a very active component of the body. So it would be better for you, as a woman, to have maybe 15 grams of protein if you're gonna do strength, or 15 grams of protein with 30 grams of carb, which isn't a lot, before you go do cardio and strength. Because this is just enough to raise your blood sugar, to circulate to the hypothalamus that, yes, there's some nutrition coming in. I'm able to get that blood sugar working. I'm able to get that blood sugar into the muscle. I'm able to stimulate the mitochondria in the muscle to actually use some more free fatty acids. I'm able, able to tell the liver that I can actually get through this and use these free fatty acids instead of storing them." It only takes a little bit of food to then have benefit for what you're doing. For a man, if he's like, comes in, "I have a black coffee. I go to the gym. I do my strength. I might do a little cardio. I have my protein afterwards, and then I might delay my meal," like, that's all right, because you have a longer window for recovery. The hypothalamus isn't as sensitive. You're not burning through lean mass. You're developing a stress on the body, and we know that it's really good that you had that protein post-exercise, 'cause that's going to create some muscle protein synthesis and hold you over till you have your meal.

    13. SB

      Okay, so I'm gonna try and explain this to you, um, like I'm a 10-year-old-

    14. SS

      Yeah.

    15. SB

      ... which is the exact-

    16. SS

      I love that.

    17. SB

      ... level of IQ I have-

    18. SS

      Perfect.

    19. SB

      ... on this subject matter.

    20. SS

      Yeah.

    21. SB

      So you've got h- this hypothalamus in the brain-

    22. SS

      Mm-hmm.

    23. SB

      ... which is basically the sensor. It's trying to figure out, make sure everything is in... I'm trying to think of that big word that someone taught me.

    24. SS

      Homeostasis?

    25. SB

      Homeostasis. Everything is level, right?

    26. SS

      Yeah.

    27. SB

      And a woman's hypothalamus is more sensitive, so if my partner wakes up, goes to the gym, has her black coffee, goes to the gym, does a big workout as she always does, her body, her hypothalamus is going to panic a little bit more-

    28. SS

      Mm-hmm.

    29. SB

      ... because it's going to assume that there's stress on the body now, and it's gonna look around to see if it has sufficient blood glucose levels, and it's g- and it's not gonna, sh- 'cause she's not had anything for a while, she's not gonna have the sufficient blood glucose levels, so it's gonna start burning her lean muscle mass.

    30. SS

      Exactly.

  17. 42:36 – 50:07

    Fasting and Exercise Differences for Women vs. Men

    1. SS

      down.

    2. SB

      So what does that say about fasting?

    3. SS

      So this is the big debate, right? So we look at fasting and where it first came out, and it's like, okay, we see that obese sedentary individuals who had to lose weight rapidly for surgery, they're put on a fasting type program to lose weight quickly in order to survive surgery. And unfortunately, a lot of those times, we look at clinical research, and it gets transposed over to health and fitness without actually asking if it's viable. So then we look at the lower end of the fitness population, people who are just learning to move and wanting to move. They're like, "I also want to lose more body fat so that I can move better. Oh, I'll start fasting." And when we see a lot of the, like, push on it, it comes from male data, again. So when we start looking at women, and a lot of women used to come with their partners to see me and say, "I don't understand. We're both doing the same kind of fasted training. He's leaning up and getting fitter. I'm putting weight on and getting slower." I'm like, "Okay, well, we have to separate it out," right? If you're a woman and you wanna fast for all the health reasons that we hear about with regards to telomere length, improving longevity, improving our body's metabolic control, then we work with our circadian rhythm, where we stop eating at, at dinner. So we have dinner and we don't eat two to three hours before bed. We have that overnight fast, and then you wanna have food within a half an hour of waking up to blunt that cortisol peak that's natural upon waking. For men, you can have variations of fasting. You can do intermittent fasting, you can do, uh, warrior fasting, and you can still have benefit. But for women, when we look at the data, and if we were to do a warrior fast, which is a 20-hour fast, four-hour eating window, for men, we see more parasympathetic drive, so they get that more focus. They have better blood glucose control. They get, uh, an acceleration of body fat loss. They become more metabolically flexible, meaning their body's able to s- transfer between carbohydrate and fat utilization. For women, it doesn't happen that way. For women who do a warrior fast, so that's a 20-hour, uh, fasting and four-hour eating window, they end up with less blood sugar control. We have higher resting blood glucose. We have more fat storage. We have more sympathetic drive, so that means the body's under stress and you're not going to be- be able to sleep or recover well. And we see a downturn of the thyroid within four days of doing this. So when we're looking at the data of fasting, again, it's pulling from the men and generalizing to the women. But when we start really looking and narrowing it down and looking at female-specific data, the type of fasting that's out there in the health and fitness world is not appropriate for women.

    4. SB

      But you would say that the sort of overnight fast, eating dinner at a earlier time-

    5. SS

      At 6:00, 7:00.

    6. SB

      ... six, six o'clock, and then eating breakfast when you wake up at, say, 8:00 in the morning or 9:00 or something.

    7. SS

      Six or seven? Six.

    8. SB

      What about the, like, three-day fast you hear about to get into, like, autophagy or whatever it is?

    9. SS

      Exercise is a stronger stimulus for autophagy than fasting is. If we look at exercise in itself is a fasting state. What happens during exercise? You start exercising. Your body is trying to provide fuel, so it's breaking down fat. It's breaking down glucose. It's breaking down amino acids. It's also creating, in a recovery standpoint, a boost of growth hormone, a boost of testosterone in both men and women that creates a cell cleanup, which is autophagy, right? So if we're looking at the difference between fasting and exercise, exercise is a stronger stress. All the things that we hear about fasting and longevity, exercise does the same. It's a stronger stimulus for it. But the problem is, we've become a lazy society, and people think exercise is too hard. As an exercise physiologist, it breaks my heart to see people who are struggling to walk down the street because we are so used to being conditioned to a certain temperature in a room, to having a car automatic opener or Uber come so we don't have to walk down the road. And I bring up that movie WALL-E from the early 2000s with the little robot who's, like, wandering around society, and you see all these people on these floating beds watching a screen, and one of the guys gets kicked off by WALL-E accidentally, falls down, he can't get up. And he's looking around going, "Wh- wh- why can't I get up? What- what's going on?" I'm like, "That's today's society, where people are- are not able to actually pull their own body weight around for a significant amount of time because it feels too difficult." Whereas if we look at all the stuff that comes out with nutrition and all the trends that come out with nutrition, from fasting to carnivorous diet to, you know, the old-fashioned paleo, all of these things that people are trying to do, if we turn to exercise and we change the modalities of exercise, are we doing intense exercise or are we doing low intensity or are we doing resistance training or are we doing cardio? What are we doing? All of these things in exercise are significantly stronger stress on the body that create more adaptive changes than all these crazy diets. But people find exercise too hard or they don't have time.

    10. SB

      So finally, in that example where a man and woman come to you-

    11. SS

      Mm-hmm.

    12. SB

      ... you would- you wouldn't recommend the woman to fast in the same way that you'd recommend a man to fast. Is there any differences that you'd recommend in training if they were, if their goal was to lose weight?

    13. SS

      Yep. Absolutely. So when we're looking at regardless of age for women because we see that women don't age in a linear fashion like men. So we have def- definitive points. We have puberty. We have our reproductive years. We're gonna have pregnancy in there. We have perimenopause. We have post-menopause. Each one of those is a different hormone profile that c- can affect the way we train. For men, you know, you just kinda go whoo and we start to see a decline of testosterone when we get into our late 50s. So when we're talking about women and training...If someone is coming in and they're in their mid-30s and they're like, "I wanna lose weight," okay, resistance training. If someone comes in and they're in their mid-40s in perimenopause, resistance training, doesn't matter. Resistance training is key for mobilizing abdominal fat and for creating more lean mass, and also increasing the amount of crosstalk between their skeletal muscle and our stored fat through little things called myokines, which are hormone signals that are released during exercise and released from the skeletal muscle. So if we say, "Okay, let's do resistance training to really recomp the body," we also want to increase our protein intake 'cause we see if you're doing resistance training with a higher protein intake, then we have complete recomp over the course of 12 weeks. And it's a very powerful motivating tool for women because, for the most part, women have been excommunicated from the strength world until recently. It wasn't kosher for women to have a lot of muscles. We see, like I grew up in the '90s with the supermodels that were super skinny, right? It wasn't kosher for women to be in the gym lifting weights. But we see this evolution change, and so we're starting to see more research come out in women in resistance training, and it's so imperative for body composition change to invoke that resistance training.

  18. 50:07 – 52:01

    Stacey's Thoughts on Ozempic

    1. SS

    2. SB

      What about Ozempic?

    3. SS

      Ozempic, yeah. So I find it interesting because of all the impact it's having on society, and it is a very powerful tool. The problem with it is no one is being necessarily taught how to come off it. So if we look at Ozempic and how powerful the GPL1 is, we see it does invoke an appetite switch where it mutes the appetite, it dampens cravings, so we see a s- rapid weight loss, but the rapid weight loss is lean mass. So that comes back to the WALL-E picture where you can't get up 'cause you don't have lean mass. I fear for society who doesn't have the opportunity to learn how to come off it through proper strength training, exercise modalities, and nutrition to support the weight loss that comes with Ozempic use.

    4. SB

      Mm-hmm.

    5. SS

      It's absolutely a brilliant tool. It's absolutely a brilliant tool, but we're falling on the behavior change. If we were to really teach people how to create that behavior change while they're using the tool, then they can come off it and not be afraid of putting weight back on.

    6. SB

      Okay, s- so would you recommend it for your, for people that come to see you or-

    7. SS

      No.

    8. SB

      ... ask you for advice? You-

    9. SS

      No, because most of the people that come see me have this 10 vanity pounds they wanna lose. I call them vanity pounds 'cause they're the ones that creep up and you can instigate little changes within the daily life to actually lose them and keep them off. For people who are struggling, who have severe obesity, they're pre-diabetic, they have other medical conditions, and exercise is definitely in the too hard basket because they get breathless just getting up out of their chair, we need to lose some weight first so that we can then implement some of the adaptive changes of exercise.

  19. 52:01 – 53:13

    When Should We Eat Around Training?

    1. SS

    2. SB

      And do you think women should be eating immediately after they exercise, and men? Or is it, does it, is there a variance there at all?

    3. SS

      There is a variance because when we look at, um, what we call metabolism coming back down to baseline, so that's your overall body coming back down to its resting state, for women, it happens within 30 to 40 minutes after exercise. For men, it's two to 18 hours, depending on the intensity. So in that, we see that if we wanna maximize our body's resistance training and muscle building capacity, we need to give it some food. We need to give it some really good hit of protein. For women who are in their reproductive years, we see 35 grams of protein post-exercise within 45 minutes will tip the muscle into muscle protein synthesis. For men, it's 20 grams, and it can be two, four, whatever hours later. When we're looking at returning our m- muscle glycogen back to normal, we don't need as much carbohydrate post-exercise as a woman, as men need more 'cause they tap more into their stores. So the window of opportunity for women post-exercise is around that 45-minute mark, but for men, it's open a lot wider.

  20. 53:13 – 54:43

    Stacey's Thoughts on Keto

    1. SS

    2. SB

      What about the keto diet for women?

    3. SS

      I am kind of anti-keto for both sexes, and I say this because when we look at the gut microbiome, that is so important. We see a decrease in diversity as we become more and more, I guess, city dwelling, and we are having less and less of, uh, variety in our food chain.

    4. SB

      Mm-hmm.

    5. SS

      We have to take care of the gut microbiome. If we look at the ketogenic diet and the high fat intake that comes with it, it significantly decreases that gut microbiome diversity, which reduces the body's ability to synthesize vitamins, to produce serotonin, to have this conversation between the gut and the brain. And for women, we're already metabolically flexible by the nature of being born with more of those endurant fibers, that there's no reason to try to do a ketogenic diet.

    6. SB

      Could I not take a prebiotic or something or-

    7. SS

      No.

    8. SB

      ... just eat more fruits and veggies and stuff?

    9. SS

      So if you're eating a lot of fruit and veggies-

    10. SB

      Sorry, not fruit, but veggies.

    11. SS

      (laughs) Yeah, no. If you're eating a lot of fibrous fruit and veg, then that's how we increase the diversity. Taking a probiotic pill just affects the upper intestines, but even that is a little bit suspect because there's only two to three companies that are making all the probiotics that are B2B, so that means business to business. And we don't really know the long-term outcome, and we can have the overgrowth of some probiotics that, again, can cause some dysbiosis.

  21. 54:43 – 56:28

    Keto and the Microbiome

    1. SS

    2. SB

      C- could I be on the keto diet and still protect my gut microbiome?

    3. SS

      I don't think so, not from what I've seen.

    4. SB

      'Cause I thought the gut microbiome was predominantly about, like, plants.

    5. SS

      It is, but you also need some protein-

    6. SB

      Mm-hmm.

    7. SS

      ... that comes from a wide variety of different sources. And the amount of fat that is taken in through a true ketogenic diet is 70 to 80% of your total intake coming from fat. And then that will cause the overgrowth of the bacteria that relies primarily on fatty acids, which downregulates all the good bacteria that relies on our fibrous fruit and veg, 'cause you're not going to be able to consume as much fiber as you need on a ketogenic diet to really invoke this diversity. If we're thinking about invoking diversity, you want 30 different plants across the week. And on a ketogenic diet, you're just not capable of being able to eat as much to create that diversity. And the reason why it's really important for women to have that diversity is because we have some gut bugs that are responsible for our sex hormone metabolism. So when we think about estrogen, progesterone, people think, "Oh, yeah, well, it's released from the ovaries and the adrenals, and it goes and hits our target tissues." But we have this thing called the second pass, where our sex hormones will be taken up by the liver, bound by sex hormone-binding globulin, shot into the intestines through bile, unconjugated or unpacked by these little gut bugs, and then shot back out in the circulation to work. If we have a lower diversity of the gut microbiome, we don't have those bugs that will help with our sex hormone, um, I guess, reactivation and the ability for the sex hormones to work optimally.

  22. 56:28 – 1:00:28

    Saunas and Cold Plunge Differences

    1. SS

    2. SB

      What about things like s- saunas and cold plunges?

    3. SS

      Yeah.

    4. SB

      Is there a difference or variance there between men and women?

    5. SS

      Absolutely. So if we're looking at cold plunge, and it's all the rage, right?

    6. SB

      Yeah.

    7. SS

      So we're saying, "Let's get into ice water." It's gonna invoke this massive parasypa- parasympathetic response. I'm going to have lots of cognition and focus. It's gonna create a hormonal response that improves my blood glucose. It's going to invoke a lot of autophagy and all the things that we see with fasting as well. And it gives me this incredible sense of being in control. Male data. When we look at women who are in ice bath, it's too cold to invoke those responses. And the reason for that is we have differences in, um, our skin sensation between men and women in- with regards to thermoregulation. So women have more, um, subcutaneous fat, so more fat under the skin, and we tend to vasoconstrict and vasodilate first. So that means that, um, blood vessels will constrict tightly, and then we'll start to have some internal changes, or if we're too hot, we'll vasodilate first, and then we'll have internal changes to create sweating. So when we look at a cold plunge, there's too much constriction, and it becomes too much of a threat to women. And their bodies don't have the same response to ice water. We see that 15 to 16 degrees C, or around 55 degrees Fahrenheit, is optimal temperature for women to experience the same effect that men have with ice. So there's a sex difference in the temperature to invoke the same response between cold water, um, immersion responses. In the sauna, everyone responds. And we see that the adaptation for sauna is different, again, for men and women, because for women, with the difference of the vasodilation and the heat before they start sweating, it takes a longer time for core temperature to come up. So women can spend more time in the heat before they start to get changes in their hormone responses and blood volume adaptations. For men, they can go in, and I kind of laugh. My husband will come in with me in the sauna, and I'll sit there for like 10 minutes. I'm not sweating yet. And he's like pouring. He's like, "I gotta get out." And it takes me like 20 or 30 minutes in order to get the same response. So when we look at the- the actual research and data that looks at acclimatization and looks at sauna invoking changes, we see again that women need more time both- long- long- longer time for an acute bout and longer time across the weeks in order to get the same cardiovascular adaptations as men.

    8. SB

      Interesting. I didn't realize that. And a typical ice bath is what temperature? It's what, minus one or something, or is it-

    9. SS

      I think it's zero to four degrees C.

    10. SB

      Oh, okay. Zero to four. Okay. So you're saying that a woman should be nearer 15.

    11. SS

      Mm-hmm.

    12. SB

      For the same benefits.

    13. SS

      Mm-hmm.

    14. SB

      Hm.

    15. SS

      Yep. (page flips)

    16. SB

      At my company, Flight Studio, which is part of my bigger company, Flight Group, we're constantly looking for ways to build deeper connections with our audiences, whether that's a new show, a product, or a project. It's why I launched the conversation cards. I've relied on Shopify before, who's a sponsor of today's podcast, and I'll be using them again for the next big launch, which you'll hear about soon. And I use them because of how easy it is to set up an online store that reaches all of you, no matter where you are in the world. With Shopify, the usual pain points of launching products online disappear completely. No matter the size of your business, Shopify has everything you need to make your business go to the next level and better connect with your customers all over the world. To say thank you to all of you for listening to my show, we're giving you a trial, which is just $1 a month. You can sign up by going to shopify.com/bartlett. That's shopify.com/bartlett, or find the link in the description below. (page flips) One of the, um, conversations

  23. 1:00:28 – 1:05:42

    Women's Use of Creatine

    1. SB

      I had with my partner last year at New Year's Eve was about creatine.

    2. SS

      Yeah.

    3. SB

      Um, I had- had some with me on the counter in our- in our home, and we were away from home, and I said to her, I said, "Oh, you should take some." And her response was, "No, that's not for women," and she went on to explain that she felt it was for, effectively, like bodybuilders.

    4. SS

      Yeah.

    5. SB

      ... and that it would, like, put on weight. And I was like, "I don't think that's true." I said, "Like, some people on my podcast have told me (laughs) that- that everyone should be taking it."

    6. SS

      Yeah.

    7. SB

      And so we sat there and Googled it. And after Googling it for a couple of, um, minutes, she was, like, scooping it into her drink as fast-

    8. SS

      Yes.

    9. SB

      ... as she possibly could. But there is a prevailing narrative here. Uh, actually, before you came, I asked AI a couple of questions about women's perceptions on creatine.

    10. SS

      Mm-hmm.

    11. SB

      And the number-one thing was women thought that it would en- gain muscle and gain w- weight, and they thought it was, um, for bodybuilders.

    12. SS

      Yep. That is the prevailing myths around creatine. And what's the expression people use? The dose, or the poison's in the dose?

    13. SB

      Mm-hmm.

    14. SS

      Right? So that's part of the creatine. So if we're looking at the bodybuilding set and how it increases muscle capacity and training status, so if we're using a lot of creatine, the dosing for bodybuilding is five grams four times a day with one gram of carbohydrate. And we see that creatine helps store water within the muscle with glycogen, and we want that for muscle performance 'cause the idea of being able to train harder with creatine is to enhance the amount of- of enzymes that are available for muscle contraction, and creatine is part of the buffering system of that. If we're looking at creatine for health and for women, the dose is three to five grams only once a day without carbohydrate, and the reason for that is women have around 70% of the stores that men have by the nature, for the most part, don't eat as much creatine-filled food as men. And we see that we use it for a lot of our fast energetics, so like for our gut health, for our brain health, um, and then also for muscle performance. So if we're having women take three to five grams once a day, it does not have the same side effects as the bodybuilding set of taking five grams four times a day.

    15. SB

      Yeah, 'cause it, on the label, it tells me to take it a few times a day.

    16. SS

      Yeah. You don't have to.

    17. SB

      And it says about loading.

    18. SS

      So this is all the bodybuilding stuff, right? So if you wanna load, we see a loading protocols over the course of two weeks, and you're starting to really saturate the body with those five grams four times a day, but for women, we see that three to five grams will fully saturate the body over the course of three weeks. So that means that all of our fast energetics, like I said, our gut, um, the intestines, and we're looking at the integrity of the intestinal cells, and the mucosal lining, and we see that there is a greater incidence of GI distress in women. I think it's something like a five-to-one ratio of women to men having GI distress running, and it has to do with estrogen but also has to do with what we call the mucosal lining of the intestines. So we wanna maintain the integrity of the mucosal lining, and creatine is really important for that. So if we're looking at saturating the body over three weeks with three to five grams, we improve that integrity, so we have less GI distress. We also see that there have been randomized control trials looking at, uh, mood and with, specifically with regards to depression and anxiety, and women who are taking three to five grams of creatine will come out of a depressive episode more so than women who are just using an SSRI. So it's really important for brain metabolism. And when we're looking at that whole loading strategy for men, that's all about muscle performance. It's not about gut health. It's not about brain health. It's about muscle performance.

    19. SB

      Just looking at some studies, creatine supplication- creatine supplementation for both men and women enhances muscle strength-

    20. SS

      Mm-hmm.

    21. SB

      ... increases lean muscle mass, improves high-intensity exercise performance-

    22. SS

      Yep.

    23. SB

      ... im- improves recovery, has potential cognitive benefits, and supports in neurodegenerative diseases.

    24. SS

      Yes, so Abbey Smith-Ryan is a colleague out of UNC, and she's done a lot of work in creatine for women. Um, and yes, we see that there is an improvement in muscle capacity because you're increasing the amount of buffer that's available for muscle contractions, but it doesn't have to be the same loading dose as men. If you are looking for performance enhancement because you want to improve a training block, or you're in physique-building, or you're gonna do something like high-rocks, and you need to have greater muscle capacity, you might wanna try the loading strategy. Yes, you will gain water weight because you're also storing more within the muscle, but for the general woman who's looking for health and performance benefits, you don't have to do a loading strategy. You just have to do that three to five grams a day.

    25. SB

      That loading strategy, for anyone that doesn't know, is basically, some of the creatine boxes will tell you, the labels will say, "For the first week or two weeks, whatever, have a huge dosage of it, and then aft- thereafter, you can kinda ease down the dosage."

    26. SS

      Mm-hmm.

    27. SB

      But I think that's kind of been debunked as something that we all need to do in all cases.

    28. SS

      Yeah.

  24. 1:05:42 – 1:11:18

    Recommendations for Women

    1. SS

    2. SB

      Are there any other supplements that you recommend women to take based on the way that we live our lives and the food that we eat?

    3. SS

      Vitamin D.

    4. SB

      Okay.

    5. SS

      Um-

    6. SB

      And why? And what does that do?

    7. SS

      So if we're looking at vitamin D, especially vitamin D3-

    8. SB

      What's the difference?

    9. SS

      So you have vitamin D2 and vitamin D3. Vitamin D2 is more of a storage form. It's not converted to being the functional form. So if you take D3, it's already a functional form, so that means your body's gonna take it in and use it as it should be. So we're looking at a vitamin D3 supplement, then we are able to boost circulating levels of vitamin D3 or vitamin D that's usable, and it's used for every system in the body. And it's really important now, especially, I'm coming from the Southern Hemisphere just out of winter. You're in the upper parts of the Northern Hemisphere in the middle of winter, and we don't get enough sun. And when we're looking at now all the worries for skin cancer, people are slip, slap, slop, you know, sunscreen, hat, clothes, and we don't get enough. And then if we're looking at our food supply, there's not a lot of proper vitamin D-rich foods. You're looking at mushrooms or fortified dairy products, and those tend not to be consumed a lot nowadays. So if we're improving the amount of vitamin D3 that we're taking in and the amount of vitamin D that's circulating, we have better recovery. We have better muscle function. We have better brain health. We have, pretty much every system is affected in a positive way.

    10. SB

      Omega-3?

    11. SS

      Yeah, Omega-3s are good, especially as we get into peri and post-menopause. We want to look at, uh, how inflammation affects the cells. So if we look at using a really good vitamin, or- or sorry, uh, really good omega-3, um, and omega, uh, I guess, we're looking at the types of omega-3s that are in there. Then we're enhancing cellular integrity that our estrogen used to help with anti-inflammatory properties. It's not something that everyone needs to take. It's something that we have to consider when we start getting into our late 30s, early 40s, maybe get a blood test for it, see how your omega-3 levels are, and then consider dosing with a really good fish oil.

    12. SB

      What about iron levels? 'Cause I've had a friend of mine, who is a woman, um, tell me that her iron levels were low.

    13. SS

      This is common, and we see that there's the incidents of a change in the norms when we're looking at the reference ranges. And I find it really interesting that the reference ranges that we have for all of our blood markers are shifting to a sicker population.

    14. SB

      What does that mean?

    15. SS

      So if we're looking at the bell curve and we're taking population data, overall, our society has become sicker. So now, we're seeing that the norms for iron used to be a ferritin of 50 or lower was considered low ferritin. Now, it's 26 for women. We look at testosterone, lower testosterone now for men is normal, and it is because that is just what a sedentary population now presents. But if someone is active and comes to me and says, "You know, I had my iron tested and it's sitting at 26, and they say that it's normal, but I feel awful." It's like, that is not normal. If you were part of my high performance athletic crew, we wanna see minimum 50, preferably 100, so we have to supplement you to bring it up. And it's a- a really specific area of how we supplement, it's supplementing every other day with a very high bioavailable iron. And when we start looking at how we are supplementing every other day with either a carbonyl or a glyconate, then we're really able to boost that ferritin and people start to feel better.

    16. SB

      What does iron do and how does someone who's iron deficient feel?

    17. SS

      So, iron is responsible for that- those heme groups that I was talking about with the oxygen carrying capacity-

    18. SB

      Hemoglobin, the blood thing.

    19. SS

      Yeah.

    20. SB

      The blood cells.

    21. SS

      Yeah, the blood cells. So iron is responsible for allowing those heme groups to carry oxygen. If we have low iron, then we don't have enough oxygen circulating throughout the body or being used by the body, so you feel very flat, very tired. You start to get really dark circles under your eyes. Um, it's a mission to do anything, so it's like a dead-end fatigue. And people are like, "This- this isn't stress-oriented fatigue or jet lag oriented fatigue. This is fatigue where I can't even walk up the stairs without getting winded."

    22. SB

      What foods have iron in them, are iron rich?

    23. SS

      So primarily, red meat is where a lot of people turn to, but if you are more plant based, then we look at leafy greens, we look at nuts and seeds, but using a lot of vitamin C with that. Preferably adding, um, a little bit of olive oil on our salads. Uh, maybe cooking in a iron skillet to improve the amount of iron that comes into the food. And we also know that we have to time it with what we call hepcidin or hepcidin, depending on where you come from in the world. It's an enzyme that decreases the body's availability of iron absorption. It increases with inflammation, so it's higher after training for about five hours in men and in reproductive women, and it can be elevated for up to 24 hours in late peri and early post-menopausal women. So basically, how do I supplement? Supplement before training or at night away from training.

  25. 1:11:18 – 1:15:05

    Blood Glucose Sensitivity

    1. SS

    2. SB

      When you think about men's and women's diets, is there anything to be aware of when we're thinking about it? 'Cause you know, me and my partner will sit down for dinner and we share the food.

    3. SS

      Yeah.

    4. SB

      So we, you know, food comes out, we... E- even when we go to a restaurant, sometimes we'll order the exact same thing-

    5. SS

      Yeah.

    6. SB

      ... and we'll both finish it.

    7. SS

      Yeah.

    8. SB

      Is that okay?

    9. SS

      Is it, is it working for you guys?

    10. SB

      Uh, the- I think part of the reason I ask is, when I did some, um, blood glucose tests-

    11. SS

      Yeah.

    12. SB

      ... I think I f- I think if- if I recall this correctly, my partner was more sense, glucose sensitive than me. And I recall them telling me that women are, have a greater blood sugar sensitivity than men.

    13. SS

      So this is the interesting part. So when we're looking at blood glucose and insulin sensitivity, it changes across the menstrual cycle.

    14. SB

      Okay.

    15. SS

      So it depends on, is she in her high hormone phase or not? If she's in the high hormone phase, which is after ovulation, uh, we have more insulin resistance. And the reason for that is when progesterone comes up, it's trying to take in everything as a building block for the uterine lining.

    16. SB

      Insulin resistance-

    17. SS

      Yeah.

    18. SB

      ... what does that mean?

    19. SS

      So insulin is the hormone that el- that is a signal for your muscles to uptake glucose, to store it.

    20. SB

      Okay, so it sends a signal to grab the glucose out of my blood, store it, which brings my glucose levels down?

    21. SS

      Exactly.

    22. SB

      Okay.

    23. SS

      Exactly. When progesterone's in the picture, insulin doesn't do its job very well.

    24. SB

      Okay.

    25. SS

      'Cause pro- progesterone wants to have more carbohydrate available to be able to then send it to the developing uterine lining, the endometriosis. Because the endometriosis becomes a really thick layer of tissue that is really rich in glycogen...So progesterone increases lean mass breakdown, or you increase your protein intake to have more circulating amino acids. It also makes your body less apt to store glucose, because it wants both amino acids and glucose to build this lush uterine lining. When we get into perimenopause, we have more insulin resistance because there's confusion across all systems of the body. And the body is like, "I don't know if I'm gonna need this glucose or not, so I'm not gonna store it." And there's a misstep in the liver and a misstep in the mitochondria, which is responsible for tapping into using free fatty acids with carbohydrate. So the body's having a higher level of blood glucose, because the body doesn't know if it should store it or not. So when your partner gets tested, depends on how old she is, and what phase of the menstrual cycle, or if she's well beyond that.

    26. SB

      So the, the part of the menstrual cy- cycle where her progesterone is highest-

    27. SS

      Mm-hmm.

    28. SB

      ... is when she's gonna be most sensitive to sugar?

    29. SS

      Exactly.

    30. SB

      And that is typically between day 19 and 23, if she has a normal cycle-

  26. 1:15:05 – 1:17:35

    Adapting Nutrition and Exercise to Your 28-Day Cycle

    1. SS

    2. SB

      So as it relates to this menstrual cycle-

    3. SS

      Yeah.

    4. SB

      ... 28 days, I'm gonna put it on the screen for anyone that doesn't understand it, um, or doesn't know what I'm referencing right now.

    5. SS

      Mm-hmm.

    6. SB

      But I'll also link it below in the comments, in the description, sorry. Um, 28 days long, there's the early follicular stage, the late follicular s- stage, the mid luteulu-

    7. SS

      Luteal?

    8. SB

      That's exactly what I said.

    9. SS

      Yep. (laughs)

    10. SB

      And the late luteal phase. (laughs)

    11. SS

      Yeah, yeah, yeah, yeah.

    12. SB

      As it relates to nutrition and exercise-

    13. SS

      Yeah.

    14. SB

      ... how do I need to adapt across these 28 days, and why do I need to adapt?

    15. SS

      So again, it comes down to the ovulation, right? So if we're looking at the low hormone phase, so that's your follicular phase.

    16. SB

      So day one to six, roughly?

    17. SS

      Yep, and even up to ovulation.

    18. SB

      Which is where?

    19. SS

      So around day 12 or 13 on a 28-day cycle. So right at that peak.

    20. SB

      12 to 13, oh, here.

    21. SS

      Yeah, yeah, yeah, there.

    22. SB

      Yeah.

    23. SS

      So this is where, um, the immune system is really r- robust, and we're really resilient to stress, and we can have a lot of carbohydrate and protein intake, and we're not gonna be that affected. We're more sensli- sensitive to glucose. It's gonna be pulled into places it needs to be. If we ovulate, after ovulation, like I said, progesterone comes up. It's only produced if we ovulate, because progesterone's produced from the breakdown of the housing of the egg. Progesterone, like I said earlier, will hold everything in the blood. It'll s- it will tell the body, "We need more blood glucose, and we need that glucose to come to the e- endometrial lining. We also need more amino acids, so we're gonna break down lean mass, or I'm gonna make this person crave more protein-oriented foods so that I can have amino acids to come in." So if we're looking at adapting, right, the only real thing that we need to be aware of is, after ovulation, if we're gonna do a high-intensity workout, we need to make sure that we have some more carbohydrate, so we're actually eating before and after, having some good carbohydrate that comes in.

    24. SB

      Which is from day 14 onwards?

    25. SS

      Yep.

    26. SB

      So from day 14 onwards, if we are gonna do a lot of, uh, a high-intensity workout or high, um, a big workout-

    27. SS

      Yep.

    28. SB

      ... then we need to just make sure we're having more carbs?

    29. SS

      Yep. And then we have around a 12% increase in our protein needs, because we have a higher amount of amino acids that are needed, one, because we're developing tissue, but two, we also have skeletal muscle turnover that we need to keep up with.

  27. 1:17:35 – 1:20:41

    Are There Days in the Cycle We Shouldn't Work Hard?

    1. SB

      Interesting. So is there any day in the cycle where we shouldn't be working out hard?

    2. SS

      That's individual. So it used to be, early days when menstrual cycle research was coming out, we saw on a molecular level that the low hormone phase was where we could really push it, and we could really get really good adaptations, because our body was really responsive to stress. Then after ovulation, we see a fuel shift. Like I said, progesterone is, is really conserving or pulling glucose away. Estrogen's also sparing it and saying, "You know, you need to go to the uterine lining." So with the change in hormones, we have a change in our fueling system. We also have a change in our core temperature, where it goes up by about .5 or .5 degrees Celsius, or around one degrees Fahrenheit, so our heat tolerance isn't as great. But because we're seeing more and more anovulatory cycles, we have to rely on the woman to track her own cycle.

    3. SB

      Which is hard.

    4. SS

      Well, it doesn't have to be as hard as what people think.

    5. SB

      Okay.

    6. SS

      It's the nuance of, "How do I feel today?" So I tell women, instead of really dialing it in and saying, "Oh, well, I think I ovulated today, so that means I should back it down," when you go to the gym, use what we call sessional rating of perceived exertion. So I tell people, "Most of the time you're gonna go in, you're gonna have a physical and a mental, right? Physical, how are you on a one to ten? Mental, how are you on a one to ten? If physically you're an eight, and mentally you're a two, warm up really well and see if that mental capacity comes back up. If not-"...then we're not gonna push too hard, we're not gonna work on technique because mentally, you're just not there. Physically, maybe you are. If you go in and you're low on both of them, then it's gonna be a technique and recovery day. You're not wasting time at the gym, you're gonna make it work for you by really working slow under the bar, nailing technique, not getting the heart rate up so much. And as we're going through and tracking how we feel, we're gonna start to see patterns across our cycle, and we can anticipate those patterns and say, "Okay, well, I know on day 21, I always feel flat, so I'm not gonna schedule a high-intensity workout that day. I'm gonna sleep in, maybe do some mobility, recover, and really know that I'm not gonna nail it that day, so I'm not gonna go push myself 'cause I don't wanna beat myself up mentally." 'Cause women do this, they're like, "I suck. I don't know why." But it comes down to that physiological variability, and for a woman to track her own cycle, understand her own nuances. If you're really onto it and you know when you ovulate, then you can take those molecular structures into play, where you know you can hit your PR and you can really push it in the low hormone phase. After ovulation, you're gonna switch it to more endurance, maybe not so high-intensity, but more tempo-type work, and then about the four or five days before your period starts where your immune system's more compromised, just kinda wanna dial it down, use it as deload. So we can take the strength and conditioning ideas of building up macro and micro cycles and deload across the menstrual cycle.

  28. 1:20:41 – 1:21:37

    When Are Women Strongest in Their Cycle?

    1. SS

    2. SB

      So where in this cycle am I gonna be strongest if I'm a woman?

    3. SS

      So if we're looking from a cognitive and a physicality aspect, it's right around where that estrogen starts to come up. So around day six...

    4. SB

      Day six.

    5. SS

      ...to about day 13, 14.

    6. SB

      Day 13?

    7. SS

      Yeah.

    8. SB

      Okay. And where am I gonna be least strong, theoretically?

    9. SS

      From about day 23.

    10. SB

      Here? Yeah.

    11. SS

      Yep, as those hormones start to come down-

    12. SB

      Yeah.

    13. SS

      ...to Sh- 28.

    14. SB

      Oh, okay, so the very end. Okay.

    15. SS

      Yeah, the very end. And the variation of those hormones coming down is what instigates a total inflammatory response. So if we're looking at inflammation which drives the menstrual cycle to start the bleeding phase, we have a change in our immune system.

    16. SB

      Bleeding happens at 28?

    17. SS

      Around day 28. So we say bleeding is day one, and the cycle is day 28.

    18. SB

      Oh, of course, yeah.

    19. SS

      Yeah.

    20. SB

      Day one to day six, typically.

    21. SS

      Yeah.

    22. SB

      Okay, fine.

    23. SS

      Yeah.

  29. 1:21:37 – 1:24:39

    Unasked Questions About the Menstrual Cycle

    1. SS

    2. SB

      What questions should I be asking about the menstrual cycle?

    3. SS

      Well, you know with the questions that are never asked is like, what is a typical menstrual cycle? Yes, we have a textbook, like-

    4. SB

      Yeah.

    5. SS

      ...from 1 to 28. That's very, very rare. Most women have a cycle that might be 21 to 40 days. The bleed cycle is something that's never talked about. What does a bleed cycle look like? Is it really six days? No, every woman has a different one, and if you're tracking what that bleed is, maybe you have two heavy days, a light day, another couple of days of spotting, and then a heavy day, that's your norm. When you start having changes in the norm, that's when you want to look and say, "Am I getting into low energy availability? Am I not recovering well enough? Or am I in my late 30s, early 40s, and I started getting into perimenopause?" The bleed pattern is so important for people to understand because that's how we have a true, inherent identification of stress. So we see changes in the bleed pattern, as well as the length of the menstrual cycle itself, when the body's not adapting to stress, and stress isn't just our daily life stress. It's exercise stress.

Episode duration: 2:04:03

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