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As an endurance athlete, nutrition is a critical piece of success. In this week’s podcast, Sonya sat down with Stevie Lyn Smith, a Registered Dietitian and avid endurance athlete, to talk all things sports nutrition. 

Stevie Lyn is a sports nutrition specialist, marathon runner, Ironman triathlete and adventurer. She knows a thing or two about preparing your body for an endurance event. She founded Stevie Lyn Smith Nutrition Wellness Consulting, PC, and writes for the wellness company, InsideTracker. She has also contributed to Runner’s World Magazine, Outside Magazine, Bicycling Magazine and Triathlete Magazine. 

Tune in to hear more about how to fuel your body, weight loss, knowing how much to eat, and more.

Foods rich in antioxidants are great, particularly Vitamin A, C, and E, so we can get a lot of those in fruits and vegetables, getting a variety of colors. Vitamin A – thinking about our orange foods; Vitamin C – of course our citrus fruits; Vitamin E – sunflower seed butter is one of my favorites for Vitamin E. Basically, I just tell people to look and see, are we getting in those high quality fruits and vegetables, nuts, seeds, whole grains? Are we getting in enough healthy fats as well, particularly Omega 3 fatty acids? If you do eat fish, fatty fish is a great source. For plant-based athletes and individuals, usually walnuts, flax seeds, those are some of my big go-tos for those individuals. But just looking at diet quality, nutrient density..
–  Stevie Lyn Smith

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Key Takeaways

  • Common biomarkers
  • How to lower cortisol
  • All about iron
  • Supplement safety
  • Inflammation vs. anti-inflammation
  • Focusing on sports nutrition
  • Weight loss
  • Knowing how much to eat




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Sonya: So let’s get into today’s awesome guest Stevie Lyn Smith. Stevie Lyn is a sports nutrition specialist, a marathon runner and Ironman triathlete and an adventurer, and she knows that nutrition is a critical piece of success, and that’s something that I also have thought about a lot and put a lot of effort to in my career as an ultra endurance athlete and just in an effort to be a healthy human. And in this week’s podcast, we talked about all things sports nutrition. Stevie Lyn Smith has her own company, Nutrition Wellness Consulting, and she also writes and works for Inside Tracker. And I’m sure you’ve heard of Inside Tracker if you’ve been listening to this podcast. And she’s also contributed to Runners Roll Magazine, Outside Magazine, Bicycling Magazine, and Triathlete Magazine. So you might guess that she knows a thing or two about preparing your body for an endurance event. And because Stevie Lyn works for Inside Tracker, I thought that we would get into some of the common biomarkers that athletes test for in the Inside Tracker tests, how to lower your cortisol, everything you need to know about iron. We talked about supplement safety because there’s a lot of questions about supplements and it’s generally an unregulated industry and also how to make sure that you’re absorbing your supplements. We talked about inflammation versus anti-inflammation and focusing on sports nutrition, and we also talked about weight loss and knowing how much to eat because a lot of endurance athletes are trying to lean out. But also, if you are too focused on leaning out, you can compromise your performance. 

If after listening to this, you’re like, yeah, I’m really interested in learning more about my body and my biomarkers, we are offering a 25% off discount for all Inside Tracker tests. So just go to to get 25% off everything that they offer. They measure a ton of different biomarkers things like cortisol, inflammation, magnesium, vitamin D. They check your liver enzymes…so much. Even just having a good baseline and knowing where your body is at today is a really great way to try to feel your best and also to perform better. Inside Tracker also offers a DNA kit so that you can learn about your genetic potential. And they test up to 261 genetic markers, and they also report wellness traits and risks. Inside Tracker also has a ton of free information on their website, and in fact, Stevie Lyn has her own column called The Inside Guide. Some of Stevie’s recent posts on her column are how to prioritize performance and longevity and endurance sports, talking about plant based diets, talking about how gut health affects athletic performance. So there’s a lot of different topics to cover. Health is a lot more than just exercising and eating well. As a health coach, that’s something that I work on with my clients a lot, and it’s a great reminder that what you do, your daily habits and the things that you pay attention to, build your foundation. And that is going to be a topic of next week’s podcast. So secret secret. There’s a little spoiler alert for next week. So go to to get your 25% off anything that they offer and let me know how it goes. I’ve had a lot of you try out and have been happy with your results and happy with the things that you’ve learned.

So here we go. Here is Stevie Lyn Smith. 

Sonya: Stevie, welcome to the podcast.

Stevie Lyn: Hi, Sonya. Thank you for having me.

Sonya: It’s great to chat with you again, because you and I have actually gone over some of my Inside Tracker blood test results, which we’ll talk about later. And I’m excited to get to pick your brain for the listener now.

Stevie Lyn: Yeah, absolutely. I’m excited to share. And it was great to chat with you too. And I hope that you’ve been working hard on those biomarkers. Your homework.

Sonya: That’s right. Homework is always a good thing. We always learn homework is bad, but that’s the fun part, right?

Stevie Lyn: Exactly. It’s like a little bit of self experimenting, too, when you have that blood data.

Sonya: So speaking of homework, you have quite a bit of interesting educational background. So can you talk about just your background a little bit?

Stevie Lyn: Absolutely. So I am a registered dietitian, which you might see people floating around with the credentials – Registered dietitian, nutritionist – same thing. Those two can be used interchangeably. So I did my bachelor’s of science in dietetics and nutrition at SUNY Buffalo State, where I also completed… I explain it as like a baby residency because people can really relate to doctors residencies. Dietitians, registered dietitians, one of the things that sets us apart from some of the other nutrition credentials that you might see floating about is that we do have to do 1200 hours of supervised practice. So for me, that was a lot of hospital rotations. We also have to then sit for a board exam to get that RD or RDN credential. And then there’s lots of other things you can do as a dietitian. So I did that. And then I worked for six years as a clinical dietitian in a hospital in DC. And then I decided to get my master’s in applied nutrition with a sports nutrition concentration from Northeastern. So I have that. And then last year, 2020, I sat for my board exam in sports nutrition. So the CSSD credential is just like another specialty, kind of like doctors have specialties, right? So that allows me to call myself a sports dietitian or sports registered dietitian nutritionist.

Sonya: It sounds like there’s a lot of opportunities and homework with being a registered dietitian. And actually, I’m not a registered dietitian at all, but out of curiosity, I’ve actually looked into that CSSD. I can never say the word accreditation. Is that the right?

Stevie Lyn: Yeah. Accreditation I know it’s a mouthful. Lot of “Cs” in there. Yeah.

Sonya: There’s so much respect for all the work that you’ve done and the 1200 hours of supervised work, and that’s a lot.

Stevie Lyn: Yeah, it’s a lot. It’s a lot of chemistry, but at least undergrad was a lot of chemistry, but it’s totally worth it. And then to be an RD, we have to do a certain number of continuing education hours every five years, and then I keep my CSSD credential, I have to take that core exam every five years, which is great, because the thing about nutrition is that it’s always changing. As we all know, I feel like there’s something new every day. So I feel like a lot of dietitians are already trying to stay ahead of reading the new research and on top of it get that continue education. You kind of already have to do it to stay in the know with clients and everybody asking you questions. So it’s fun to keep learning and keep growing. And a big thing is happening and an open-educated mind. Yeah.

Sonya: And something that I think is really great, especially now is that people are taking a lot of or they have a lot of autonomy around their health. And people are realizing that nutrition and the things that you eat have a massive impact on anything from lifestyle, diseases, to performance to sleep. I think it used to be you would just outsource all that to your doctor and just assume your doctor knows everything. And you worked in a clinical setting as well. So, yeah, doctors are amazing, and we need doctors. But doctors are not registered dietitians.

Stevie Lyn: No, they’re not. I mean, lots of amazing doctors. I learned so much from some of the doctors I worked with in the hospital, but I found that the doctors I learned the most from had no hesitations with asking either myself or other dietitians, like, hey, I have this patient, can you help them? Because it’s kind of like everything in life, right? We would hope that you delegate to the experts, right? It’s okay to learn and educate yourself that at a point, there’s a time to delegate, like, taxes. Since I’ve become a business owner. I’m like, I have an accountant. I’m not even going to try. I have my account and do my taxes because he’s an expert. It’s just attorneys, everything else. At a point, you can do a certain amount and definitely advocate and take control of your health. Especially being in a hospital setting and dealing with some autoimmune issues myself, I find it’s very important to make sure that your voice is heard as an individual, but there is a point in time where we do need to delegate for some help from experts.

Sonya: So what made you decide to focus on sports? Because there’s a lot of extra things that you’ve done. A lot of extra education.

Stevie Lyn: Yeah. So it’s funny, because when I look back, I never planned on being a sports dietitian. I know a lot of dietitians or nutrition students right now. They’re like, oh, I want to be a sports dietitian. I want to work with athletes, kind of like a little bit more glamorous than working in a hospital or food service or the other hundreds of settings that dietitians work in. It just kind of happened. I’ve been an athlete my whole life. I played soccer, lacrosse, growing up. I played lacrosse for a season in College at the Division III level. And then after I retired from that, I learned how to swim and started running again. And eventually that very quickly turned into a marathon into an Ironman. It escalated quickly. And then kind of once I was in the endurance world for a while, I kind of started to get some sports nutrition gigs. And while that was kind of happening, I was reading all of the things and trying to learn all the things because, of course, I have a ton of nutrition knowledge from school, but in my program at least, there was no sports nutrition rotation in my clinical rotations or no sports nutrition class. So I was educating myself and then gaining experience from other sports dietitians. And then there was a point where I just kind of decided to take that leap and see if I could kind of put myself 100% in the sports world. Here we are.

Sonya: It sounds like number one, you like type two fun. A common trait that I’ve noticed amongst podcast guests is curiosity and love of learning. And it sounds like you have both of those in spades.

Stevie Lyn: Lots of type two fun.

Sonya: Even school. Type two fun.

Stevie Lyn: Exactly. Yeah, it really is.

Sonya: I recently wrote an article for one of my sponsors, Gu Energy Labs, where I interviewed a couple of sports dietitians, asking them what their common myths were, that they would come up with in their clients and in their research. And they told me some of theirs. What is one or two sports nutrition myths that you commonly come up against? And what is the actual research behind the “truth”?

Stevie Lyn: The “truth”. Yeah. Oh, man. What are some of the biggest ones that I come up with? A lot of my clients don’t come at me with a lot of, like, really kind of out of left field myths. To be honest, a lot of what I see, though, is a lot of resistance around fueling and what we should be using for fueling and fasted workouts. Like fasted cardio is something I see a lot of people coming at me with and kind of restricting their fueling in a hopes to change their body weight or body composition is a big thing I see. Because basically a lot of individuals see it as like empty or unneeded calories or just sugar and sugar is bad, kind of thought process.

It’s not really a simple sentence myth, but it seems to kind of be where there is that most kind of resistance. And I spend a lot of time talking about carbs. We want to eat these carbs before our workouts and during our workouts and kind of just the thought process of the people who don’t train with fuel. And then they go out and do their first race and they drink all this Gatorade. And they say Gatorade makes me sick. While some people do have issues with fructose, which is in Gatorade, it’s not everybody and it’s actually a very small amount of people who have issues digesting and processing fructose. It’s more of that they literally never trained to get rid of drink four bottles while exercising and exercising, of course, does change how our body utilizes energy, digest food breaks it down, et cetera. So there’s a concept of called training the gut, being able to…obviously, we need those carbohydrates and calories that energy while we’re training anyway so we can have an awesome training session, but also kind of just like we train our cardiovascular system to do the type of two funds, we should also be training the gut so we can tolerate sports fuels on race day at the same race day intensity. I see a lot of people try to work around that one because the intensity is also going to play in on how your body is going to break down and process that nutrition you take in. But also, it’s a great spot to find what sports fuels or if you want to go a real food kind of fueling route, what works for you, because I’m sure you and I, Sonya, have different fuel plans and strategies, and that’s okay. I would say that’s probably the biggest thing I find the most resistance with for my clients.

Sonya: I think that people think that there’s just one recipe that works for everybody. And this has been what everybody, all the experts I’ve talked to have said, hey, look, there’s a baseline that you can start with, but then you have to figure out what works for you because everybody… Even like myself versus somebody else on a race course, the intensity that we can hold might be different. So the way that you fuel might be different. And what came up with those interviews was exactly what you said it was.

People are unsure or have resistance to eating carbohydrates, especially a more refined carbohydrate in some cases while you’re actually exercising and that you need to fuel yourself early and often whenever you’re out doing endurance sports and other sports.

And I think that there’s a lot of confusion out there because people will see other people who are like fat adapted athletes. And there are people that do that. But I think that that is not the norm. And I don’t know much about fat adapted athletes. Maybe you can shed some light on that.

Stevie Lyn: Yeah. With the fat adapted athletes, at a point, you can gain some of that adaptation, but it’s only going to get you so far, basically. You can’t do the whole race, however long it is endurance wise without carbohydrates. And I find a lot of those people that they come in so low that they’re already at a huge deficit when they’re then trying to add the carbohydrates in. I’ve seen it go very poorly in some athletes, and also at that point, then it goes back to they’re not really training with those sports fuels. So then they try to take them on race day, and it doesn’t go well. I’ve seen a couple of people try to do it in a full Ironman, and I felt very badly. It did not end well for them. 

Sonya: Eat in your training what you’re eating on race day. And the same goes for what your breakfast is. And don’t try anything new on race day. I know some of us I’ve done that before, and I don’t recommend that at all.

Stevie Lyn: Sometimes it happens. We hope it doesn’t happen, right. But it’s also the people that, and this is just my personal opinion of sports nutrition who wants to do all liquid nutrition in an Ironman. I understand the thought process behind it. Right. Liquid is already very easily digested. It’s not going to be like having a solid or chews or gel. But I’ve seen so many bottles fly off the back of bikes in an Ironman, and then some people are saying, well, I lost 500 calories on the bike because my bottle flew off the back.

And then if you come off that bike behind, then you’re not really going to have a lot to show for on the run. That’s one of the big things that always makes me feel very…it makes me kind of like cringe when I see those battles fly off.

Sonya: And another thing that you mentioned was people doing fasted workouts because they want to change their body composition or they want to lose weight. And I have a two part kind of commenting questions around this. Number one – does that work? And number two, a lot of times people will say, well, I’m running 20 miles a week or 20 miles at a time. I’m running like 50 miles a week or I’m exercising 15 hours, 10 hours a week, and I’m not losing weight, and they try and exercise their way into weight loss.

Can you comment on that?

Stevie Lyn: Yeah, absolutely. And with the fasted workouts, I know some athletes really struggle eating first thing in the morning, especially if they’re the crew that gets up at 3:30 to work out and 4:00 hour. And for the most part, for those people, I try to at least get them have some sports drink in. I tell people a little bit of carb is better than no carb. And for people who struggle to eat a lot of volume in the morning, we make sure the night before is a pretty solid meal.

But for the most part, when we’re looking at people who are doing it with the intentions of losing weight, changing body composition, it kind of works against them, because fasting, under eating, under fueling, can increase cortisol levels. It is a stress state for the body. The comment on people who try are like, oh, well, I run 20 miles a week and 20 miles a time, 50 miles a week, and they’re trying to overexercise themselves into losing weight, they end up more often than not putting themselves in this high stress state from under fueling. And when cortisol levels are elevated, weight gain is one of the consequences of it. Unstable blood sugar is another thing changes, like I said, to your body composition. So it kind of is counterintuitive when people are like, oh, I only 1500 calories a day. Why am I not losing weight? It’s because they’re so woefully under fueling that they’re putting their body into a stress state.

Sonya: And I think this brings up the next question is like, how do you know how much to eat? Because a lot of times people are like, well, I feel like I’m eating too much. Or maybe I’m eating too little, but I feel like I’m eating enough. So how do you know how much to eat?

Stevie Lyn: Yeah. So it’s a great question. And it’s something that people I think sometimes feel badly when I work with them, one on one, that they’re under eating, unintentionally. But I feel like, as a culture, we’re not really taught to eat enough, right? It’s always everything like, oh, eat less, don’t eat this. Don’t eat that. Cut this out. That like, I never ever blame anybody for not knowing how much they should eat. So basically, though, to answer your question, I typically for, like, an endurance athlete who’s training, I tend to not ever want to see anyone under 2000 calories a day, like bare minimum females. Males, I say usually 22 to 2500, being like the very low end for an active male. And that’s just kind of a general rule of thumb. Of course, like, if someone’s training a ton, it’s going to go higher. But I see a lot of people coming in at 1200, 1300, 1500,1800 calories a day, and that’s even for males. And that’s not nearly enough. So those are kind of at least just like a very general rule of thumb. Of course, smaller people, you’re going to need a little bit less than larger people and then taking into account different kind of factors, like training load, training intensity, et cetera.

Sonya: And like, if you’re tired or if you’re not recovering and this is a recurring thing, then put more on your plate. I think the reason why we’re taught, like, hey, restrict restrict is because the number one, the media, especially if you’re female, is always telling you that you need to be smaller and you’re not good enough and all these things. But also a lot of the standard foods that go on people’s plate are highly processed foods that are nutritionally bankrupt. If you’re adding in and eating lots of foods that are whole foods that have a good source of nutrients, chances are that those calories you’re putting in are going to actually help you go faster and help you sleep better and help you just thrive and maybe even bring that cortisol down.

Stevie Lyn: Yeah, absolutely. And one thing you made me think of it when you said nutrient bankrupt foods. Also, what I see a lot of people is like, oh, I just fill up on salads and lots of steamed vegetables. Don’t get me wrong. I like it when people eat vegetables. But for athletes, I see a lot of people eating, yeah, it’s got nutrients…there is a lot of good quality in a salad, depending on what kind of grains, what you’re putting on, et cetera. But it also takes up a lot of volume that doesn’t leave space for some of those more dense, really nourishing food.

So a lot of my clients to say, where are the carbs on your salad, like, give me some grains and beans, potatoes, etc.. So a lot of people who are under eating, under fueling tend to fill up those, like, very big plates of salads and veggies.

Sonya: I’m so glad you brought that up, because a lot of people… I’m a plant-based athlete. A lot of people that listen are plant curious. And one of the biggest, I think problems amongst people, especially people that just want to eat more plant based, is that they do exactly what you said. They have all the best intentions. They don’t get enough calories. And like you said, whole grains are really good for you. Beans are really good for you. And whatever diet that you’re eating, like, just trying to eat a balanced amount of the foods on your plate.

Stevie Lyn: Exactly. The salad can still be there. I just want it to be a smaller little square on your plate.

Sonya: Especially the night before an event. So we started talking about cortisol a little bit, and you work with Inside Tracker. And Inside Tracker has been a podcast sponsor and supporter of the show, so I really was excited to get to chat with you to go more into detail on some of the biomarkers that can be tested on an Inside Tracker blood test. And I’ve been using Inside Tracker since 2017, especially as a plant based athlete and person, of course, for years I’ve been doing this since 2013, I’ve had doubts and things like that and being able to just check and make sure that I’m doing the right things and get that confirmation has been awesome. And also just people who are like, maybe they just feel off and like a normal family doctor like this isn’t really in their wheelhouse, like this type of performance nutrition. So can you talk about how you got involved with Inside Tracker and kind of the bottom line as to why people do these tests?

Stevie Lyn: Yeah, absolutely. I have actually been an Inside Tracker user since 2016. I started just a little bit before you. I learned about it from Twitter, I think. And at that point, I was really deep into my full Ironman career. 2016 I think I had done, I don’t know, five or six full Ironmans. I did 10 between 2012 and 2019. So 2016 was the year the year before I started toying with a double Ironman season. Yes, I did that a couple of years. So Inside Tracker was a very, remarkably helpful tool for the amount of training I was doing with all of that long distance racing, just a lot of training, long distance swimming, all of it…marathon, ultra marathon. So I also as a dietitian and an athlete. I fell in love with it. And then in 2018, I interviewed and started working with Inside Tracker. It was kind of nice and a great opportunity. I mean, at that point, I knew everything about Inside Tracker already, inside and out. Obviously very strongly believe in it. It definitely helped me survive and thrive during those double Ironman seasons, which led me to PR my full Ironman distance and be able to manage having a full time job, a part time job and all of the training. Very firm believer in it. And I just love, as a company, watching us grow as the science changes and always evolving and seeing how we can help people. Like you said, your traditional doctor relationship wouldn’t look at nearly as many biomarkers as we do. But also in the kind of the view we take at these biomarkers. Regular lab testing with your doctor, you get the reference ranges for a very large group of people, and then they’re really just looking like, are you sick or are you not sick with a chronic disease?

With Inside Tracker, it’s much more personalized and defined to each of us as individuals, but also looking at, hey, you’re probably pretty healthy if you’re training for an Ironman and doing all this racing, long distance racing, how can we take you from good to great really is what the ranges for the biomarkers that we look at kind of speaks to.

Sonya: And I love that it’s good to great. And it’s also that people have that control in their training and in their lives, in most cases, to be able to change their lifestyle a little bit to have an optimized zone using the terminology at Inside Tracker.

So what are some common biomarkers that are out of range that you see for endurance athletes?

Stevie Lyn: So one of the big ones is vitamin D, but that is also across the board. Inside Tracker users definitely tend to see a lot of unoptimized vitamin D zones, which to me as a dietitian, I’m like, well, this is kind of like an easy fix, right? We know it’s very hard to get vitamin D from food sources, so usually if someone has a low level, I don’t even hesitate to supplement right away just to get that number up. I also see people who are taking supplements, but they’re just not taking a vitamin D supplement correctly. It’s one of the ones that we want to take with food, a meal or snack that contains fat so that your body is properly absorbing it. So kind of a less exciting one, but definitely one I always see to be an issue. I see a lot of high cortisol. I know we already briefly talked about that, usually for a number of reasons, but I find a lot of endurance athletes are just doing a lot of things. We all have a lot of work. We tend to be a little bit more on the type A personality side. I mean, I will throw myself into that category, whether we’re training for whatever race or events, and then we have a family. We have work commitments, school, community, et cetera. We put a lot of pressure and stress on ourselves. Like I said, I know a lot of athletes are doing that 4:00 a.m. wake up. Sleep tends to be sacrificed as well, so that one is usually just kind of figuring out how can we balance all of that stress in the stress bucket?

Where can we be a little bit kind to ourselves? A lot of people who I work with who are just runners. Maybe it’s working in more low impact activities and cutting down on some of the running intensity and running days. There are some supplements adaptogenic, namely ashwagandha, that can help reduce cortisol levels as well. That works for a lot of athletes. Sometimes it’s just kind of revisiting to see where we’re at and, you personally, if I have a high cortisol and a low ferritin, I will put myself in a running time out and take at least a week off of running because I know personally I cannot run myself out of those. Ferritin, know I just mentioned that’s another big one, that’s the stored form of iron. So it really gives us an accurate picture of an individual’s iron status. This number will drop before hemoglobin does, because your doctor usually only tests hemoglobin. Unless you have a good relationship with your doctor or they know you have a history of anemia or deficiency. So those two things, at least for me, it’s very hard to continue to train and feel well and bring those numbers back up.

Sonya: With the ferritin and the iron, this is something that you and I had talked about because I always have a good level of ferritin and iron storage. My hemoglobin is usually pretty good. I’m looking at my Inside Tracker results right now. The data points. Sometimes the hemoglobin is a little bit low, but my blood iron…and these are all things that everybody would get if they did a test, you would actually get access to these details. My blood iron is high pretty frequently, and I thought, Well, my ferritin is good. My hemoglobin is low, but my blood iron is high. So what does that mean?

Stevie Lyn: Yes. So typically, are you taking a supplement right now? If you don’t mind me asking.

Sonya: I take a multivitamin that has iron in it, like a non heme iron, but that’s pretty much it.

Stevie Lyn: So the thing with serum iron is it does fluctuate daily, so it can go up and down. That’s why we look at that ferritin. That’s kind of our accurate picture. If people are supplementing with iron, I do look at serum iron and transferrin saturation to see, okay, is their body absorbing all the iron that they’re taking? Because you’ll notice a lot of the iron on the shelf that you can just buy at the store is like 65, 80 milligrams. If it is a recommendation for you to take an iron supplement, we start at 14 milligrams, and we won’t recommend over 25 milligrams just because your body can only absorb so much.

And a lot of times with iron, whether we’re taking a supplement or not, it’s looking at how we can optimize our absorption, which is kind of like a very delicate tango. I feel like you’re always kind of dancing around like, okay, how do I time this iron rich meal? I can’t have this too close to my coffee because the tannins in the coffee are going to inhibit some of the absorption, et cetera, et cetera. So that’s the fun game of iron.

Sonya: And I also think this is interesting, and I haven’t read the current research on this so you have to correct me if I’m wrong. But heme iron, like your body can’t get rid of it except through bleeding. Whereas, like, non heme iron, I think, can your body get rid of that on its own or just doesn’t absorb it if it doesn’t need it?

Stevie Lyn: Yeah. It’s not absorbed as efficiently as your heme iron. Yeah.

Sonya: So you can overdo it if you’re taking heme iron and you’re eating lots of food that has heme iron in it and you can overdo the amount of iron and that causes oxidation. Do you guys see that or is it usually a deficiency?

Stevie Lyn: For the most part, it’s deficiency. I have had some people come in and they’re just taking way too much iron. But typically people are on the lower end and not over supplementing more often than not.

Sonya: The supplementation thing is really interesting because a lot of people are afraid of supplements because number one, it’s relatively unregulated and there is the NSF certification. It’s called NSF, right? When it’s certification?

Stevie Lyn: Yeah. And then there’s one USP, which is not for athletes. Usually I tell people to do NSF or certified sports.

Sonya: That protects you, hopefully from getting contaminations. If you are being tested for doping, you don’t test positive from a supplement that you are taking.

If you go to the store, I think it’s a good time to bring up just how to buy supplements in general, because I kind of have the go to brands that I go to because those have been recommended by experts like you or other people. But there’s so many different brands of supplements on the shelf, all different prices. How do you know what supplements to get?

Stevie Lyn: Yeah. Great question. So if you test with Inside Tracker anywhere there’s a supplement recommended, there’s a nice little drop down that says, show more. We will tell you the dose to take, how to take it, like I mentioned how to take vitamin D, anything you need to know about the supplement. But we also have recommended brands that our science team has pulled. It’s usually two for each recommended supplement, so it helps kind of cut down that noise. You can always go to a site called, so that’s like L-A-B-D-O-O-R dot com. And that will give you insights. It’s all third party testing and grading on different supplements. So you can say like, my brother will text me like, oh, this is a Costco. Is this fish oil good? And I’ll just go to Labdoor quick and look at the brand, and I’ll give it like a grade, like an ABCD, et cetera. So I find that to be a very helpful resource if there is something else you’re looking for. But Nature Made is usually pretty good. Now Food is another one. NSF-wise, Thorne has a lot of great quality products. Those are kind of some of the go tos. I don’t have any affiliations with any of them. So I just looked for something that, like you said, is going to be like a safe and useful product for sure.

Sonya: So the next question I have is about inflammation, hs-CRP and inflammation is part of being an athlete and recovering. What do you see with the C reactive protein and the inflammation markers amongst athletes in general?

Stevie Lyn: Yeah. That’s a great question. For the most part, I tend to see with athletes, they might just be like a touch outside of that optimized zone, like in the 1.0, 1.2 so a little bit of that low rate inflammation, but nothing terribly super high or super concerning. With those athletes, I do recommend that we do focus on dropping that down into the green, optimize zone. For hsCRP. It’s usually a pretty tight zone for levels of inflammation to keep it in check. Some people will be talking and I’ll see an hf-CRP

 of four, which is very high for people who are not so familiar with the ranges, and they’ll be like, oh, well, I had an Achilles injury or I was sick before this test, and that can spike that marker. Some people actually tested the day after their COVID vaccines, and their numbers were very high, which is expected, right, because it’s an inflammatory response in the body. So if there’s an illness or injury, we will expect to see that spike up, which isn’t really the worst thing because it shows that your body is responding to that said illness, said injury, said vaccine, et cetera. And that’s what you want. You want that inflammatory response. But of course, we don’t want it sitting high all the time. We’ll also see this an athlete spike after races, very hard effort that this number will be elevated for up to seven days after a marathon, the event, and then it should start to drop back down towards normal ranges. Back before I started working for Inside Tracker, I did test two days after one of my full Ironman, that double Ironman season. I did Lake Placid in July, Louisville in October, and my hs-CRP spiked to 19, which is very high. So there was a lot of recovery after that season, for sure. But I did it just to kind of see, like, I want to see what this Ironman in the two days after. So we knew it would be elevated because it was in that seven day window, which that was pretty interesting to see.

Sonya: Yeah, I’ve done a test. It was after I did the Cape Epic. It was like two or three days after, and I had flown all the way across the world. I landed, and the next day I took a test just because I wanted to see, what does my body look like when I’m at my absolute most wrecked point and it was not nearly as bad as I was expecting. But coming back to inflammation, what are some of your favorite anti-inflammatory foods that you recommend?

Stevie Lyn: Yeah, absolutely. So, of course, foods version antioxidants are great, particularly vitamin C and E. So we can get a lot of those from fruits and vegetables, getting a variety of colors. Vitamin A thinking about our orange foods. Vitamin C, of course, our citrus foods. Vitamin E, sunflower seed butter is one of my favorites for vitamin E, but basically, I just tell people to look and say, like, okay, are we getting in those high quality fruits and vegetables, nuts, seeds, whole grains. Are we getting in enough healthy fats as well, particularly Omega three fatty acids? If you do eat fish, fatty fish is a great source. For plant based athletes and individuals, usually walnuts, flax seeds. Those are some of my big go to for those individuals. But just looking at diet quality, nutrient density, of course, I love a good ice cream cone and sprinkles, but looking and being like, okay, where have I had a little bit too much of those like refined sugars. And I love red wine, but I know I think I briefly mentioned autoimmune disease, but now, since I’ve been diagnosed with rheumatoid arthritis, when I eat those foods, I feel it and I’ll feel it a little bit in my hands. Not everybody gets that feedback. Of course I get that feedback, but it’s more of those foods that I’m like, okay, time to get a little bit more of the nourishing foods in. So those are the big things. There’s really not any superfood per se, but just going back and looking like, okay, am I eating enough? Am I eating enough of those full quality foods. Kind of doing that check in.

Sonya: Maybe after a highly stressful situation for your body, just adding in a little bit more of those for a little bit. Still enjoying your ice cream and your wine in moderation because we’re humans, and nobody is here to be eating this, like, 100% perfect diet on paper.

Stevie Lyn: Right. I know. I always think about my Instagram story, and I was like, this past weekend, I went paddleboarding. Then I had nachos, like, a huge plate of nachos, and then Sunday was like, ice cream and ribs. And I was like, oh, man. And I’m always posting it. I was like, I promise I eat vegetables.

Sonya: That was funny. Like, years ago, I was actually a craft beer rider.

Stevie Lyn: Oh, wow.

Sonya: And I would write about beer, and it would be like, I’d do it for some of the cycling publications, and I’d post about it. And then people thought that I drank all the time, and it was so funny because I was like, well, no, I sample it, but I’m not getting wasted. And I’m not even drinking beer every day, but because I would post about it, people literally thought that I was just drinking all this beer. So that was a wake up call. Like, oh, I should probably be careful about what I post because people are going to read into it.

Stevie Lyn: I made some great ratatouille yesterday, and I posted that.

Sonya: All right. So you talked about fat, and I think that fat is something that a lot of athletes are afraid of and avoid because they’re afraid of gaining weight or not losing weight. What shows up in the biomarkers if somebody’s not eating enough healthy fats, like, what shows up as a deficiency?

Stevie Lyn: That is a great question and typically tend to see that in the testosterone group or the hormones, basically as kind of where that manifests. Of course, for female athletes, I do like to just make a little pointer that if you are on oral contraceptives or have ever been on oral contraceptives, this group will be skewed by oral contraceptive use, even in the past, just by the nature. So it’s a little bit hard if you’re on birth control – SHBG – which is a sex hormone carrier that is high, because basically, you’re flooding your body with hormones. Your body’s going to give it more SHBG to bind to it. And DHEAS, which is a sex hormone precursor, this is the marker we test in place of estrogen because it won’t fluctuate with your cycle. Right? It’s hard enough to find a rest day to test on, et cetera. So we don’t make females track your cycle to kind of get accurate, stable numbers. Your body uses DHEAS to make different sex hormones, including estrogen. But like I said, with the hormonal birth control, if you’re on it, or even if there’s been past use, you’re giving your body extra hormones. So it’s not using the DHEAS. This number tends to be lower. So just kind of a little pointer that this DHEAS number is what I look at to see, like, are we getting enough of those healthy fats? We need fat to produce those hormones. But again, just as, like a little note, I like people to know that that can skew it as well. SHBG tends to go high in males when they aren’t eating enough as well. Same with some of the testosterone levels for the male athletes. We will see those off, too.

Sonya: So, DHEAS, which does one of these tests, they can look, that’s kind of the pool that makes all these other sex hormones.

Stevie Lyn: Yes. Exactly.

Sonya: And what happens if that number is high?

Stevie Lyn: So when DHEAS is high, we typically… it tends to… you should get a flag to talk to your provider. It can indicate some potential medical diagnosis or something that needs clinical intervention.

I usually send people to the OBGYN if that number is high.

Sonya: I’m just kind of scrolling through here. What about some of the more insidious things like cholesterol and things that might be high or low and you can’t really feel it?

Stevie Lyn: Yeah. Cholesterol levels, the lipid panel. I see a lot of athletes with unoptimized lipid panels. Some of it is we can identify as more of a genetic tie. I do see a lot of those athletes who kind of go skew on the other side of things and go more low carb, high fat, definitely have seen that impact cholesterol levels as well, in a negative way, elevate them, because one of the biggest things we can do to help reduce our cholesterol levels is make sure that we’re getting enough soluble fiber. And if you’re cutting out things like whole grains and legumes and going very high fat, low carb, you will miss out on a lot of that really awesome fiber. So I tend to see that a lot with some of those athletes who are anti-carb or not eating enough of them.

Sonya: Fiber is your friend. And you said soluble fiber. What’s the difference between soluble and insoluble for people who might not know?

Stevie Lyn: Yeah, of course, all fiber is important, but soluble fiber dissolves in water. Insoluble fiber does not dissolve in water. So they both have very important benefits. So most of your plants are going to contain both of these, but in different amounts. A soluble fiber dissolves. It creates kind of like a gel, and it can help improve digestion. Like I said, help to reduce blood cholesterol levels, can also help reduce blood sugar levels. Insoluble fiber attracts water into your stool or your poop, basically, to make it softer and easier to go to the bathroom. So again, both are very important. They serve their own purposes, but that’s valuable to fiber, in particular for cholesterol levels and also blood sugar management as well.

Sonya: So feeding the microbiome and also being able to poop, which is very important.

Stevie Lyn: Especially for a race.

Sonya: Something that we hopefully all like to do because it feels good.

Stevie Lyn: Right? Exactly.

Sonya: I had this really awesome gastroenterologist Dr. Bulsiewicz on the show, and if you follow his Instagram, he’s always talking about poop and what your poop should look like. And like, adults really talk about that. I have a toddler who we’re going to potty train at some like, he’s only 18 months, but that’s going to be something we probably are going to start talking about a lot pretty soon.

Stevie Lyn: Yeah. I mean, I always joke, and I didn’t realize it until I worked in the hospital, I was like, wow, big chunk of my job is talking to people about their poop. My patients used to love talking about their poop, and I was like, okay, here we are.

Sonya: So you and I talked about how we have actually done an Inside Tracker test, like, right after a really strenuous event. But when is the best time? I mean, it’s about testing, changing some things up and retesting to see if what you’re doing is working. But when is the best time to do a test?

Stevie Lyn: That’s a great question. I think it’s very valuable, especially for athletes, very active people to do a test kind of at the end of your off season, start of your season. I like to call it like a baseline test so we can see where our numbers are at after we hopefully have taken an off season, given our bodies a little bit of a break from the training, got more sleep, reduce stress, et cetera. See where the baseline is as you start your season and see where you can make those adjustments going into bigger training blocks, training season, et cetera. I always think it’s good to check in halfway through your season. Maybe if you know you’re going to have a big event coming up in six weeks to kind of check in, is there some fine tuning I can do in these last six weeks of training? Because at that point, you’re kind of seeing okay, my body’s under this stress. Am I recovering? There’s biomarkers that will show muscle damage, muscle breakdown, or do I have enough B12, where is my iron? Where is my stress load? How can I kind of adjust these next six weeks? Can I push a little bit harder, or do I need to be a little bit more conservative with my training? Other times, if you’re really feeling off, a lot of athletes tend to be more in tune with their body than the average person. Like, last October, there was no racing, but I was hiking in the high peak region of the Adirondacks in New York, and I was with my girlfriends, and I was huffing and puffing up the mountain, and I was like, okay, I really haven’t trained that much, but his shouldn’t feel this hard. So I got a test afterwards, and my ferritin had dropped 10, which is like, very, very low. The bottom goal is at least 40 for me. Okay, this is right. I need to increase my supplement dose that I was taking and adjust from there. So any time where you’re really just feeling that you might be struggling, it’s good to kind of check in on those numbers as well.

Sonya: Okay. So getting a baseline test and then maybe doing it either when you’re not feeling very well or before, like, your main event of the year. You mentioned six weeks. How long does it actually take to see some movement in these biomarkers?

Stevie Lyn: Every biomarker is different. Of course, there’s no simple answer. So for most people from that kind of looking around, our season typically tell people to wait at least three months. So usually three to four months is kind of the sweet spot, because if you’re looking to improve your, for example, your cholesterol levels, you’re going to want three months of a concentrated effort to kind of see the needle move. But something like we’re looking at muscle recovery and breakdown, if you’re using it as a tool in your season, you should be able to see those numbers hopefully improve in a shorter period of time. They move a little bit more quickly than other biomarkers. B12, you could see if it’s low and you can identify it six weeks out from a race, you can make an impactful change on that level, usually through supplementation at that point, to see an increase before you head into your main event.

Sonya: So there are some things that can change relatively quickly to help you perform.

Stevie Lyn: Ys, exactly. Performance wise. Yes. But certain things, like I said, like the lipid panel, you want to give a little bit of time if we’re not really like I said, using it around racing or an event usually every three to four months if you can. I tell people at least twice a year at a minimum, just because, like you said, yeah, the baseline information is great, but we’re taking these actions. We want to see if these actions work. It’s always a little bit of a journey of guided, self experimentation, like I added in turmeric for cumin supplements to see how it helps with my creatine kinase because I had never done it before, and I kind of changed up my training routine. I was like, oh, let’s see how this works. We’ll just give it a shot. I haven’t retested since I started, so I don’t have any feedback on it.

Sonya: I was hoping to hear some results!

Stevie Lyn: No. But how I changed my iron supplementation has given me excellent results. I kind of dug out of that ten to a 26 with everything else in check. So I was very happy with that for sure.

Sonya: What did you do?

Stevie Lyn: I’ve actually started taking my iron supplement after my workout in the morning because I read a new research paper about hepcidin levels, which is a compound associated with inflammation and that they found in the study with female runners that if the runners supplemented with iron within 30 minutes after finishing their morning workout, they saw an increase in ferritin levels because the hepcidin compound and inflammation was low for that 30 minutes post exercise, and then it continued to rise throughout the day.

Sonya: That’s a great tip for people to try.

Stevie Lyn: Yeah. So it’s not in an Inside Tracker recommendation yet. That was just from my reading and my research. But I have dug myself out of the iron because I used to take my iron supplement before bed and then I switched it to the morning because I always work out in the morning. Otherwise, it just does not happen. And I take it with a very big glass of orange juice. And I’ve been seeing great results.

Sonya: You’re getting your vitamin C with your iron supplement.

Stevie Lyn: Exactly right. I was like, we’re going to get the most out of these two little pills I’m taking every day.

Sonya: My last question for you, and there might not be an answer to this, but people of all ages are athletes, and we’re actually seeing a lot more people doing especially endurance sports into their 60s and 70s. How did these recommendations change, or do the ranges change as people get older?

Stevie Lyn: Yes, they do change. Age has taken an account.

Sonya: Something that I learned that was really interesting is that seniors actually need quite a bit more protein.

Stevie Lyn: Yeah, absolutely. To maintain the lean body mass as we age. I know it’s all about maintaining that as best we can, for sure.

Sonya: So, Stevie, if people want to work with you one on one, are you taking clients right now? And where’s the best place to find you? 

Stevie Lyn: So I will be taking clients starting at the end of September. It is now on September 6, so I will be taking some new clients. You can find me. My website is, and it’s spelled Stevie like Stevie Nicks or you can also, if you’re interested in my ice cream cones and sometimes my vegetables, but mostly my dog, you can follow me on Instagram at @Stevielynlyn. So it’s S-T-E-V-I-E-L-Y-N-L-Y-N like I said, a lot of dog content. He’s very cute, though.

Sonya: I love it. And, yeah, just make sure to check out to listener if you’re just curious about some of the things we’ve talked about, and even if you don’t want to do an inside tracker test, TV has given us so much information on how to optimize our health and performance. So thanks so much for coming on the show.

Stevie Lyn: You’re welcome. Thanks so much for having me.

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