So thank you for having me, I'm Dr. Ackerman, and I'm going to be speaking as the exchange lecturer from AMSSM for AAPMR. I was asked to speak about sports nutrition, and I emailed back and said, are you sure you want me to speak? I'm actually not a dietician, but I'm happy to be here and talk about some of my research. So basically my disclosure is I have no relevant financial relationships, I'm actually a director of a female athlete program, and I'm a sports doctor and an endocrinologist. So this talk is going to talk about some of the things that are relevant to mostly female athletes, studying female athletes and their nutrition, and some of the important issues regarding female athletes. So this talk is really going to discuss the basis for athlete sports nutrition recommendations to date, describe important considerations for accurate female sports and nutrition research, describe the causes and consequences of low energy availability in athletes, so specifically talking a bit about triad and reds, and then it's going to provide some basic female athlete nutrition advice and discuss some future directions. So it's important to realize that the majority of sports science research has been performed in men. So there's really a paucity of females being studied when it comes to nutrition and athletes. And when we talk about the 1300 exercise medicine studies that were published from 2011 to 2013 in the British Journal of Sports Medicine, the Medicine and Science in Sports and Exercise, and the American Journal of Sports Medicine, women made up about 39% of total study participants. So a researcher and an author, a reporter actually looked at that paper that was done by Costello noting this paucity of research, and then she took it a further step and looked at the follow up for the first five months of 2015, looking at MSSE and AJSM, and looking at the studies by gender and the participants by gender. So studies by gender was about 27% of studies looked at just men, 69% looked at both, and only 4% of studies looked strictly at women. So here the number of overall participants was better, it was 42%, but studies that were just focusing on women was only 4% of the sports science research. When we break that down and look at the different topics, so disease, basic physiology, metabolism, diet, and obesity, injury, social issues, and performance, I highlight a few here. So in terms of metabolism, diet, and obesity, there were 13% of studies that were strictly devoted to men, 87% that had men and women, which was good, but again, there was absolutely none that were done that were done just women alone. So when we're trying to think about nutrition for female athletes and thinking about their physiology, often that's not being directly addressed. Looking at injury and looking at performance, there were some women, but it was only 2% of the studies in injury, and in performance, it was only 3% that focused just on women alone. Well, why is this? Well, for one thing, women can be hard to study. We always want to be thinking in general with women and men when we're doing nutrition studies, the general training status and fitness of the athlete, the pre-intervention dietary status of the athlete. You want to think about the type of exercise studied. So are you looking at a time trial versus exercise to exhaustion to see what the nutritional intervention is doing? You want to think about the duration and intensity of exercise just prior to the intervention. But then when you talk about women, it's important to think about the phase of the menstrual cycle. If they have menstrual dysfunction from low energy availability, if they're in perimenopause, if they're past menopause, if the athlete's pregnant, is the athlete on a birth control pill? Do they have other underlying hormonal things such as PCOS? So a lot more complications. And then of course, studying women can be very time consuming and expensive. So for example, studying for urinary hormones daily for four months and 120 women would actually be $1 million. So you can imagine that this is very cost prohibitive for most people trying to do research in this area. And then when we talk about menstrual cycle considerations, it's important to understand what the cycle is doing. So in the left-hand column on the top, you see what happens in a typical menstrual cycle. So the beginning of a menstrual cycle is day zero during the first day of the bleed. And that's when you have hormones at their nadir. So estrogen, which is seen in yellow, and progesterone, which is seen in purple, are both low. Even FSH and LH are low at that point. Then you get to the follicular phase, and you see that estrogen increases. Then you have ovulation, there's this LH. Estrogen drops briefly, and then it goes up again. And then in that follicular phase, you really have an increase in progesterone. So in the follicular phase, in the early follicular phase, you're going to have this really low estrogen and progesterone concentration. And then later in the luteal phase, you're going to have elevations in estrogen and progesterone. So these are very different phases. And when you're talking about what's happening nutritionally or how a nutritional intervention affects a woman, it could be very different from the follicular phase to the luteal phase. In the second diagram on the left, you see what happens in menopause. And you can see the first half of that diagram, you're really having those fluctuations that happen with estrogen and progesterone. And then as women get closer to menopause, you can see that FSH and LH rising. When they get to menopause, they have a drop in their estradiol and in their progesterone. So it's really low again, sort of like pre-puberty. But now their FSH and LH are high. So there could be nutritional effects when you're looking at a woman who's premenopausal versus postmenopausal. And then finally, that last diagram on the left is looking at what happens when someone is on a birth control pill. And this is just looking over the course of a 28-day month. And basically, you have these increases in estrogen and progesterone depending on what's going on with the pill. So if someone takes a continuous dosage of estrogen and progesterone during the phase of their cycle when they're taking this hormone for 28 days, they might take the pill for 21 days and then a placebo for the last seven. You can see that there can be fluctuations in the hormones every single day as they're taking that pill where they have a big increase and then it drops, a big increase and it drops every day. So we have to really take into consideration when we're studying nutritional interventions if a person is on birth control and where they are over their lifespan. On the right side of this slide, you can see that even in a normal cycle, you can have variations from woman to woman. So this is looking at a typical cycle and it could be a different phase or a different stage when people are going through, for example, ovulation. So someone might have a 24-day cycle, which is completely normal, or they could have a 33-day cycle, which is completely normal. So in this case, it can be helpful to study the hormones that are happening around ovulation so we can kind of track where the person is having these hormonal changes because one woman having her period might not have the same length of cycle as another woman. And then we have to think about the phase of the menstrual cycle. So we talked about the follicular phase, ovulation, and then the luteal phase, but some people choose to think of it as the early follicular phase, the late follicular phase, the time of ovulation, earlier luteal phase, mid-luteal phase, and late luteal. And so here now you're talking about multiple time points and trying to study a nutritional intervention in a series of women and trying to get that all to match up can be very tricky. So we have to decide when we're talking about nutritional effects in different women, how do we know this? Is it all based in men or has it been studied in women and are we studying women in the same phases? And the fact is very few studies have actually compared multiple nutritional interventions based on the menstrual cycle using any kind of standard definition for what the menstrual cycle is. So when we go back and just talk about women and sports nutrition, I think it's very important to talk about some of the basic issues that come up with female athletes. And one of the things that has come up time and again is the female athlete triad. So this was one of the first things that really was studied in women athletes when they started to notice a syndrome that was occurring. So it was really the work of Barbara Drinkwater back in the 80s and then some others in the early 90s that made people start to think about this concept. And the concept was defined in the early 1990s by a group of people that were studying and informed in a group in sports medicine. And the group came up with this term, the female athlete triad, which was this interrelationship between low energy availability or eating disorders, amenorrhea, not getting a menstrual cycle, and then osteoporosis or low bone density. And a position statement was written by that interest group back at ACSM. It came out in 1997. It was then updated in 2007. And it came from, it started as a triangle, and then it became this whole spectrum. And each entity existed along the spectrum. So energy availability could be optimal energy availability, or it could fall all the way down the spectrum to low energy availability with or without an eating disorder. There was eumenorrhea, having a normal cycle or having some subclinical menstrual disorders and then falling down that spectrum into hypothalamic amenorrhea. And then there was optimal bone health and then falling down, maybe having a few stress injuries and some signs for low bone density and then full osteoporosis. And in fact, all of our athletes live somewhere on this continuum. And ideally, we want them in that upper right. So basically, a weight-bearing athlete who is eating appropriately for how much they're exercising has normal menstrual cycles, and they actually should have higher bone density compared to people who are non-athletic. And then people often can fall down somewhere along those different continuums down into the left-hand corner, but we want to keep them from getting there. A great study that was done by Anne Hoke actually found that up to 78% of high school varsity female athletes were found to have one or more components of the triad. So it's really common to have one of these at least, and it's important that we're always on the lookout for it. So energy availability is something that has been defined based on caloric intake and related to exercise expenditure. And Anne Lauchs, Dr. Lauchs at the Ohio State University did some studies that actually talked about energy availability and having a dose-response relationship with LH pulsatility. So LH is coming from the hypothalamus. It's stimulating – or sorry, LH is coming from the pituitary. It's stimulated by GNRH and LH from the pituitary is then having an effect on the gonads. And what she found when she looked at recreational adult women is that when energy availability fell below 30 kilocalories per kg of fat-free mass per day, LH pulse amplitude and LH pulse frequency changed significantly. There started to become abnormalities in these. So the way she defined energy availability was this dietary energy intake minus exercise energy expenditure normalized to fat-free mass. And nowadays we can estimate fat-free mass by DEXA. There are various ways to try to estimate them. Some are more accurate than others. DEXA is one of the more accurate ways to measure fat-free mass, but it really does require some standardization. So in an ideal world, you would have somebody not exercise that morning. You would have them be equally hydrated compared to other people. And when they have repeat DEXAs, there can be some effects based on their nutrition and glycogen stores. So even DEXA is not perfect, but it's fairly close and it can be of good utility clinically and for research to determine what fat-free mass is for an athlete. So for example, if an athlete were to eat 2,000 calories a day, and then she were to run 600 calories worth of exercise, and she had a fat-free mass of 51 kilograms, her energy availability would be 27.5 kilocalories per kg of fat-free mass per day. And so Dr. Laux had determined that there were some hormonal disruptions that occurred at 30. And so an athlete like that, who might think that they're eating an appropriate amount is only getting in 27.5 and would have likely some of those hormonal disruptions. Now, since that original work by Dr. Laux, there have been other studies to determine, is this 30 an absolutely perfect number that applies to everybody? And the fact is, it isn't because probably there's some variation from person to person. So a lot of hormonal disruptions were seen in her studies when energy availability dropped below 30. But it may be that people actually need to have an energy availability closer to 45. And I would argue that in adolescence and people who are growing or under significant stress do need a much higher energy availability, but there's likely personal variation. There are people that will lose menstrual cycles below 30, people that will lose menstrual cycles above 30. And so it really is a bit individual. And initially, it was thought that this negative energy balance or this low energy availability would lead to disruption of the hypothalamic pituitary ovarian axis, and that that low energy availability led to low estrogen, and that that led to low bone mineral density. And that was partially true. But actually, as energy availability drops below 30, as Dr. Laux noted in her studies, she found that bone protein synthesis and mineralization decreased, insulin, which enhances amino acid uptake decreased, IGF-1, which is a variation of growth hormone that is secreted by the liver, decreased, and T3, a form of thyroid hormone, decreased. And all of these effects occurred within five days of the onset of energy deficiency and without a reduction in estrogen concentration. So clearly, there are other things going on that affect bone besides the estrogen alone. And everything on this slide is basically important for bone. So we've looked at a lot of these different markers. And in athletes with low energy availability, particularly in women, we see that there's a decrease in BMI, fat mass, and lean mass. There's a decrease in FSH, LH, estradiol, and androgens. There's a decrease in insulin, glucose, IGF-1, T3, and leptin. And there's actually an increase in fasting PYY. These are forms of dietary hormones and hunger hormones. So fasting PYY, ghrelin, cortisol, and growth hormone resistance. Everything in green is very important for bone. And everything in red actually has a negative effect on bone. And you can see that these arrows are going in the wrong direction. So in 2014, the International Olympic Committee decided to update their statement about the female athlete triad. And they had noticed that there were actually some effects that they were seeing in terms of performance. They noted that there were some other health effects that they had noticed in their athletes. And they also found that there were male athletes who were struggling with low energy availability. And they were looking for a term to kind of make it more all-encompassing. And so they came up with this term relative energy deficiency in sport. And they came up with diagrams, which we'll discuss. And by 2018, they actually did an update in that statement as well to talk about where the research had gone to kind of support this concept. So when we look at the first diagram, the health consequences, and we go around the circle, you'll notice that there's still that triangle because the triad is still so important. So with low energy availability or relative energy deficiency in sport, you can find you still have menstrual dysfunction and you still have impairments to bone health. But as you go around this spoken wheel diagram, both females and males experience decreases in endocrine function or changes in endocrine function. They have changes in metabolism, changes in their hematologic system, effects on growth and development. There are psychological effects. And notice the arrow goes in both directions. So somebody who's experiencing psychological issues may have less energy intake or a lower energy availability. And people who are really suffering from REDS or low energy availability will also have psychological consequences. Other consequences are cardiovascular effects, GI issues, and immunologic dysfunction. From a performance aspect, if we start again in the upper right corner, there certainly are increases in injury. There's decreased training response, impaired judgment, decreased concentration, decreased—sorry, I'm having trouble reading my slides—decreased coordination, decreased concentration, irritability, depression, decreased glycogen stores, decreased muscle strength, and decreased endurance performance. And so one of the things I really like about the REDS model is that for some athletes, talking about bone density doesn't really resonate with them. If they haven't had a stress fracture or a bone stress injury, they may not think that all of this applies to them. But when you start to talk about these other effects, they might have had some of these other health issues or they might have seen some of these performance effects. And so it might be enough of a red flag for them that they might buy into the concept a little bit so that we can help them improve. So we did a survey of 1,000 female sports medicine clinic patients. These patients were 15 to 30 years of age. They came into our clinic for a variety of sports injuries, and we made sure that they exercised at least four hours a week and were on some sort of sports team. And we basically had surrogate markers of low energy availability. So we wanted to know about disordered eating or eating disorders. And we asked them if they experienced this. We also gave them the beta Q, which is a brief eating disorder questionnaire for athletes. And we gave them the ESP, which is an eating disorder screen for primary care. And we had about an 85% response rate. And kind of surprising to us, 47.3% of our athletes screen positively on at least one screen. And the key here really is that Venn diagram to the right. So you notice that each of those things is a different screening approach. One is the self-report. One is the ESP. One is the beta Q. And there were very few that answered yes to all three. But there were many. There were 47.3 that actually responded positively to at least one. So it really does depend on how you're asking the question. And I would encourage people to keep a lookout for eating disorders and disordered eating and thinking about asking it in different ways to the same people. So just here is a review article that we did looking at the endocrine changes that can happen with REDS, both in women and in men, where we are so far with the male studies. And certainly we need to do a lot more work in this area, particularly in men. But some patterns that we see fairly consistently, when you drop energy availability enough, you will see a decrease in women and men. Some studies did not show that decrease in women. And some of those patients in those studies were not ruled out for PCOS or hyperandrogenism. But when people were screened really well and their energy availability was low enough, women also had low testosterone, as did men. We see in terms of energy homeostasis and appetite regulating hormones that the resting metabolic rate in leptin were down in women and in men. Oxytocin and insulin were both down in women and men. In terms of the thyroid, free T3 can be a marker in low energy availability. And then growth hormone is actually increased. So there's typically a decrease in IGF-1, but there's an increase in growth hormone resistance. So growth hormone does not have that same kind of effect on the tissues. So just to go through a few of these circles, when we talk about the thyroid, there have been some studies looking at amenorrheic athletes who are under-fueled compared to eumenorrheic athletes and healthy controls. And looking cross-sectionally, the amenorrheic athletes had lower T4 and T3. In terms of 27 subjects who are amenorrheic or eumenorrheic or healthy controls, the TSH response, so this is the hormone from the pituitary, the response was blunted in amenorrheic athletes compared to eumenorrheic athletes when they were given thyroid-releasing hormones. So they tried to give them a stimulation, giving that hypothalamic hormone to the pituitary to try to stimulate the TSH response, and it was blunted in those amenorrheic athletes. And then when you looked at 27 eumenorrheic non-athletes, so these are just normal women who get their cycles, and these people were then given different energy availabilities, they found that four days of exercise but different total energy availabilities actually disrupted the thyroid. So when the energy availability was between 19 and 25, there was a decrease in T3 and free T3. And then when there was a drop in energy availability even lower to 10.8 to 19 kilocalories per kg of fat-free mass per day, there was actually an increase in T4 and reverse T3. So they had more of a sick-you thyroid appearance as they were more deficient in energy. There's also an interesting relationship between the hematologic system and with iron stores and energy availability. So we know that many athletes with reduced energy availability have iron deficiency. Iron deficiency may worsen the hypometabolic state associated with decreased energy availability. So T4 synthesis and T4 to T3 conversion actually rely on iron. Iron deficiency may promote energy deficiency. So it shifts ATP production from an oxidative phosphorylation to anaerobic pathways to a less efficient system. And iron is needed for reproductive function. So for follicular development and corpus luteum function. So bone health may be further impaired by iron deficiency. So there's a strong relationship between iron and the triad and with reds. We looked at amenorrheic athletes, eumenorrheic athletes, and healthy controls. Again, these amenorrheic athletes were eating less and had a lower energy availability than the eumenorrheic and the healthy controls. And so we found overall that athletic activity increased the cross-sectional area of bone. And we're looking at this through HRPQCT. So we're looking at cross-section bone of this high resolution peripheral quantitative CT. Those pictures to the lower left are actually pictures of the tibia. So when somebody is exercising over a long period of time, in general, they're going to have a wider tibia during adolescence as they have a greater moment of inertia. So athletic activity in general makes the bone wider. However, we found in the amenorrheic athletes that they had a decrease in their trabecular number and a decrease in their cortical thickness. So the bone, unfortunately, even though it was wider, actually had fewer trabeculae in the middle and added a less strong cortex. They also had a decrease in trabecular and total bone mineral density. And when we applied an engineering program called finite elemental analysis, we found that they had a decreased stiffness and failure load. So they had weaker bones. And these athletes actually had a higher rate and a bigger history, a greater history of bone stress injuries. So the bone, unfortunately, is weaker, even though it's wider than the non-athletes. Another thing I think is really important in terms of REDS is to talk about some of the performance effects. So I really liked this study that was done looking at junior elite female swimmers. So these are high-level swimmers, and they looked at cyclic athletes, those who got menstrual cycles, and ovarian-suppressed athletes, low estrogen and progesterone levels. And they were monitored every two weeks over 12 weeks. So this is over the course of a season, and they looked at the ovarian-suppressed. Those, of course, had low estrogen and progesterone levels throughout the season. And they had a decrease in T3 and an IGF-1 at week 12 versus those who were cyclic or had normal cycles through the season. The energy intake and energy availability were lower in those ovarian-suppressed. And the take-home here is the ovarian-suppressed actually had an increase in their swim time. So they actually got slower, while the cyclic, the ones who got their periods, got faster. And so here you have a group of athletes, all of whom are doing the same exact training. Some aren't getting cycles and are undernourished, and some are getting cycles and are eating appropriately. And those who have appropriate energy availability got faster, and those who did not got slower. And so it's something I can really use as an example to the athletes that I know who are training so hard, trying to get faster, but just aren't fueling appropriately. In our survey, we found, just by asking questions, that there was a 1.5 times greater odds of decreased endurance performance by self-report with low energy availability versus adequate energy availability. So when I think of athlete nutrition, I like to think of it as kind of a hierarchy. People ask me, well, what should I eat? I'm training. What do you recommend? And our dieticians, who know much more about nutrition than I do, really always want to emphasize the basics. And I think of this as, what are the basics for the athlete? So energy availability and hydration are the crux of everything. That is the base of this pyramid. After that, when we know they're getting enough calories, we want to make sure they're getting the right macro and micronutrients. Then we want to start thinking about the specifics about the timing of their food, so pre- and post-exercise fueling. And then it's good to think about the exercise intensity and the duration of the exercise, maybe the type of exercise. You can tweak the kind of food that's available depending on the kind of athlete that they are. For women, we want to be taking into consideration their endogenous hormones. So what's going on with their menstrual cycle? And then if they're taking any exogenous hormones, are they on a birth control pill? Then as we're talking about women, you're thinking through the lifespan. So what are other aging effects? How do we support the nutritional needs of an adolescent differently from a post-menopausal woman? And finally, individualization. So are there food preferences? Are there other medical considerations? And we have to put all of that together when you start talking about specific nutritional recommendations for somebody. So let's talk about some of the basics and what we do know about nutrition in general when you give nutritional advice. You want to think about the duration, the intensity, and the frequency of the exercise. Typically, nutritional advice is based and standardized to body mass. And then with women, women are typically not only smaller than men, they also have a lower lean body mass to fat mass ratio. Then we take into consideration sex hormones that could affect metabolism and weight. And therefore, studying women and then guiding athletes requires more thinking. So studying, again, the amenorrheic, eumenorrheic, oligomenorrheic athletes, the OCP users, the masters athletes, and pregnant athletes. And the studies are just not there in most of these populations. We want to study the different phases of the menstrual cycle in eumenorrheic athletes. Then we want to study different OCP combinations. So just saying, oh, well, this study was done in people on the pill. There are about 150 different pills to choose from in the US. There are many different types of progesterone and there are different dosages of estrogen. And then we want to apply these results in individual women appropriately in consideration of these findings and the own individual needs. So this is just a general guideline. You can look at this paper, the general female endurance athlete guidelines. Basically, they recommend that energy intake is greater than 45 kilocalories per kg of fat-free mass, plus the energy spent during physical activity. For protein needs, it could be 1.2 to 1.4 grams per kg. That was the standard recommendation. And then more recent research has suggested maybe 1.6 grams per kg per day for a female athlete. But note that that recent research was based off of female endurance athletes who were doing moderate intensity exercise 1.4 or sorry, 1.5 hours per day. And they were studied in the mid follicular phase. So that's very specific. When we talk about carb loading, the studies about carb loading have often recommended greater than eight grams per kg. So that is a significant amount of caloric intake for somebody who might be smaller. This is really for efficient, efficient if the total energetic balance is adequate, but if somebody is not eating enough, that might be a huge component of their diet. For iron, the general recommendation is 18 milligrams per day. But this could change depending on what the person is doing for their training and if they're on the pill. So for somebody who's on an oral contraceptive and may have lighter menstrual cycles, they may not need as much iron, it could be 11 to 12 milligrams per day. It also depends on if they have really heavy menstrual bleeding, if they are doing running and doing a lot of endurance. So there can be foot strike hemolysis just from hitting the ground with running. And then just an endurance activity in general, whether it's swimming or running can also lead to more red blood cell turnover. So that could also cause an increase in iron needs. In terms of calcium in general, we say that somebody who's 19 to postmenopause or two menopause needs 1000 milligrams a day. But an amenorrheic athlete may need more and a postmenopausal woman may need more. And we need to be splitting up that calcium because a woman only absorbs 500 milligrams of calcium at a time. Vitamin D recommendations are more typically based off of the level in the blood. So there are recommended daily allowances. But often, if you're not getting that level up to 30, just having the recommended daily allowance of 600 might not get the job done. So we need to make sure the person fills the tank that their vitamin D levels at least 30. And then often about 1000 international units can maintain that level over 30. And then finally water really depends on how much people are sweating, how much they're training. And we often base our hydration recommendations on the urine status and what somebody's urine looks like. So it should be a light yellow and they should be making sure that they're they're getting enough hydration so that they're able to urinate and get a light color urine, not completely clear and not super dark. When we talk about women's hormones affecting nutrition, so just to touch upon this estrogen is an anabolic has an anabolic effect. So it has a protein sparing effect. And we know that during endurance exercise at approximately 65% of maximal oxygen consumption, women oxidize more lipids and therefore decrease carbohydrate and protein oxidation compared with men. estrogen also impairs gluconeogenesis. And during the luteal phase, there's less reliance on muscle glycogen during submaximal exercise in the fasted state compared to the follicular phase and compared to male athletes. So when a woman has exogenous carbs that can help them overcome that impaired gluconeogenesis, so they have the fuel that they need for their exercise. So for example, carb loading, there has been work done in women looking at endurance athletes at different phases. And we know that mid follicular phase carb loading of 8.4 to nine grams per kg of body weight per day, increased muscle glycogen concentration about 17 to 31%. But there weren't improvements in the time trials. So does it matter? In the mid luteal phase, muscle glycogen concentration was unchanged or only slightly increased only about 13% with that carb loading dose. Again, improvements in the time trials weren't seen, but improvements in cycling time to exhaustion at 80% VOT max was shown. So this did allow people to cycle longer. In men, we see there's an increased muscle glycogen concentration of about 18 to 47% with carb loading. In looking at women who are on an OCP, and this is specifically a triphasic ethinyl estradiol with the progesterone levonorgestrel, so a very specific OCP, there was increased muscle glycogen concentration in the mid follicular and mid luteal phases. And this could be because estrogen levels were similar in both phases. So the estrogen dose that was given at during that pill was the same, even though the progesterone dose changed because it was a triphasic. So back to a point I made a couple slides earlier, carb loading is often considered about eight grams per kg of body weight per day. But that can be very hard with somebody who has a lower caloric intake. So if you have a female who weighs 60 kilos, and she's eating 2000 calories, that would require 96% of her total caloric consumption to be carbs. And that's not likely to happen. So again, back to the pyramid, we first have to think about what are the basic caloric requirements for the athlete, and then start thinking about these macronutrients and then start thinking about things like carb loading. So potential macronutrient racks for female athletes in relation to ovarian hormones. Again, I'd refer you to this paper, because I think it can be helpful for some of these specifics. For a habitual diet, protein requirement, it's been looked at in humaneric and endurance training athletes, probably about 1.6 grams per kg per day. And remember, this was just based on a study looking at the follicular phase. In terms of days before exercise, modified carb loading can be helpful. This has been looked at in humaneric athlete and the follicular phase and endurance athletes. So this would be increasing the energy intake by up to 30% to achieve a carb intake greater than eight grams. Again, could be hard if people aren't eating enough calories. Just a few hours before exercise, we're talking about that pre-exercise feeding. This has been looked at in humaneric athletes in the luteal phase, in triphasic OCP users, and a high carb meal or snack three to four hours before exercise can be helpful, and then it can reduce the demand on the endogenous glucose production. During exercise, exogenous sources of carbs can be helpful. So taking in carbohydrate snacks, simple sugars, this has been looked at in humaneric endurance athletes. And this would be about 60 grams per hour during prolonged exercise to again, reduce the demands on endogenous glucose production. Finally, recovery after exercise. So carbs, protein and carbs, this has been looked at in humaneric athletes, both in the follicular and the luteal phases. And ingestion of carbs as soon as possible, as soon as practical following prolonged glycogen depleting exercise can be important. So again, you're trying to replete those glycogen stores. When we talk about general nutrition and hydration considerations, basically, lower resting muscle glycogen, the follicular phase can be overcome by carb loading, but it can be hard to do that. Pre exercise feeding and or carb ingestion negates the estrogen induced reduction in gluconeogenesis. Female athletes need to pay extra attention to recovery nutrition in the luteal phase to offset the increase in protein catabolism that breakdown and then estrogen and progesterone affects the hormone and neural control of thirst, sodium regulation and fluid retention. So in the luteal phase, actually progesterone does have an effect because progesterone is higher. And this can actually make women more susceptible to hyponatremia. hormonal therapy and menopausal women lowers the threshold for osmotic AVP release. So again, this can increase basal plasma volume expansion, decrease urine output. And so these postmenopausal women can actually be at a higher risk for hyponatremia. estrogen enhances antioxidant antioxidant capacity in females. And so more work needs to be done to look at those effects and determine if people should be taking antioxidants or using that as an advantage to actually stimulate a pathway that's occurring in women. supplementing with dietary sources of antioxidants may be prudent in those with amenorrhea or in menopause, but we still doesn't we still need to see what else we can be doing. And it probably doesn't compensate for the lack of estrogen. We do know that fish oil may aid in inflammatory disorders such as dysmenorrhea, and those associated with menopause. We also know that vitamin D and calcium play a role in fertility possible in dysmenorrhea as well as bone health. However, they can again compensate for a lack of estrogen. So energy availability is very important. And then branch changed, I'm sorry, branched chain amino acid oxidation may be greater when estrogen is low. This may have dietary implications for those with amenorrhea or in menopause. So these are just some subtle things that we can be thinking about in terms of nutrition and women, but more work needs to be done. And we need to be studying women at different phases of their life. Most importantly, we need to think about the potential female athlete energy and nutritional issues. And this was a nice review done by Melinda manure, talking about just the overarching themes that we see so frequently in our female athletes. So inadequate energy to meet energy demands that low energy availability, inadequate macronutrients, carb, protein and essential fats to meet the demands of various training phases, inappropriate timing of food types and types of food around exercise and competition that can really help with performance and recovery, dieting for weight loss to achieve a specific body type or to compete in a certain weight class. So really understanding about those weight fluctuations and what is realistic. Elimination of food groups, we know that when people go on to special diets, or they are in restrictive diets, where they're remaining there, they're preferring certain groups are not in their diet, such as a vegan or some people that's following people that are following very specific diets, they might be missing out on various types of food, or it might also mask and eating disorders. So it's important to work with a dietitian when following a really strict diet. And then of course, the inadequate micronutrients that are needed for bone health. So calcium and vitamin D, red cell production, zinc, iron, folate, and vitamin B 12. And then energy production, the various B vitamins to maintain overall health. And I would leave with this, you know, we really need to increase spending on female sports science and nutrition research, there may be a great opportunity here for women to use our physiology to our advantage. male sport organizations absolutely have more money. So they're able to study men. And there's a lot of funding that comes out of these male sports. We have to remember that women control about $20 trillion, 85% of consumer spending, and women comprise 47% of the US civilian workforce. Women comprise and control 51% of the personal wealth in the US, an estimated 29 trillion. So the money is there. And we have to be choosing to study 50% of our population. If we do the studies, we might find that nutrition for female athletes is very specific, but we need to find those answers. And the way to do that is to really approach female athlete and sports science nutrition research, starting over in that left. So data mining, what do we know now? And where are the gaps, then jumping over to observational and correlation and prevalence studies? What can we learn from what's being done currently, then intervention studies, let's think about those ways to study the menstrual cycle, do the nutritional intervention studies appropriately. So we compare the different groups. And then when we get results, really promoting that optimal practice, being an advocate and explaining these findings so that we can actually be affecting our athletes in a positive way. So I'd like to thank you very much for allowing me to be your lecturer today. I welcome you to join us for our fifth biennial International Female Athlete Conference, where we'll talk more about sports nutrition and other issues that affect the female athlete. And I'm happy to take any questions. Thank you

sports nutrition

female athletes

research

female athlete triad

REDS

nutritional recommendations

micronutrients

individualization