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Welcome, hi, I'm Mikki and this is Mikkipedia where I sit down and chat to doctors, professors, athletes, practitioners and experts in their fields related to health, nutrition, fitness and wellbeing and I'm delighted that you're here.

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Hey everyone, Mikki here, you're listening to Mikkipedia and this week on the podcast I speak to Amy Lee Bowler. She's a PhD candidate, sports nutritionist and registered dietitian and we are discussing her research all about the use of continuous glucose monitors for athletes. We discuss glucose metabolism and what impacts glucose use outside of just the food we eat and the sporting context.

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monitor measures and what it might be able to tell us about fueling the athlete or not. We discuss the strengths and limitations of CGM use in the athlete context and where Amy feels the application for this is going. We also discuss a recent paper from her PhD looking at dietitian practices at assessing for energy availability in athletes and the key considerations for research found.

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Her research seeks to understand the current practice pathways in subsequent dietary management used by sports dietitians when assessing and managing energy availability in athletes. Her PhD research ultimately aims to support sports dietitians managing energy availability in elite triathletes. And Amy and I talk all about her own history in that triathlon space.

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nutrition researchers in Australia and it was such a pleasure to be able to speak to her and sort of get the real current feel on the ground for the CGMs in the athlete context because there's just so much hyperbole out there about how they may or may not be able to be used. Before we crack on into the interview though, just a reminder that the best way to support the podcast is to hit the subscribe button on your favorite podcast listening platform.

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podcast out there in amongst literally thousands of other podcasts so more people get the opportunity to learn from the guests that I have on the show. Alright team, I will put a link to Amy's profile and that paper into the show notes, but for now please enjoy the conversation I have with Amy Lee Bowler all about CGM use in athletes.

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Amy, thank you so much for taking the time to chat to me this morning on what looks like a very hot sort of, oh, has been hot and humid in Brisbane. It's nice to hear that you're getting a little bit of a reprieve from that. Are you from Brisbane? Yes. Yeah, always lived in Brisbane. Yeah. Nice. I'm actually on the Gold Coast today, but yeah, always lived in Brisbane. Oh, and do you do part of your research in the Gold Coast and Brisbane or because you look like you're in some sort of like laboratory?

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Yeah. So I'm actually based predominantly on the Gold Coast for most of my PhD study. And then I also work on the Gold Coast, but I live in Brisbane. So I do a lot of travel. But yeah, predominantly everything's on the coast for me. Yeah. Okay. So you're a registered dietitian and you're also a PhD candidate and you're looking at energy availability and elite triathletes.

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Yeah, so I guess when I started my PhD we sort of had a bit more of a focus on elite triathletes because my So my supervisor and Dr. Greg Cox he's quite a well renowned and established sports Artistician in Australia and I'm sure there's some Kiwis that would know him quite well as well But um, so he's got a very extensive background in triathlon work with triathlon and went to a number of Olympics with them

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started my PhD, we started out looking specifically in triathletes. And I guess as we kind of gone through the journey, we've expanded our study a little bit to look more at endurance athletes in general. Obviously, we know that low energy availability is a really prominent issue in endurance athletes in particular. And so I guess expanding expanding our search and, and including a number of other athletes in our study has just broadened our scope and

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of energy availability on other athletes as well. My other supervisors, Vernon Coffey and Professor Louise Burke, who I'm sure a lot of people know, have been involved in a lot of other sports as well. So we just kind of felt that it was best to broaden our scope and have a look at all endurance athletes and the effect of energy availability on them. So, yeah. Yeah, now that's awesome. And Amy, are you an athlete? So I used to be, and I guess this is kind of how I got

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and dietetics in the first place is that, so when I was younger, I was actually a swimmer, so competed at national level in swimming. And I saw a sports dietician, Angelique Clark actually, and she was still practicing in Australia. And I don't think she knows this, but sort of when I saw her, I kind of got inspired and thought, okay, this is something that I really wanna do. And so from there, it kind of just,

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I guess it just happened where I started a nutrition and dietetics degree myself just out of interest. And then having always had that sporting background myself and being interested in sport, that's kind of, I guess why I went down the sports dietetics path. So yes, but yes, answer to your question. I did used to compete in swimming. Don't sort of do it as much anymore, but still enjoy a little bit of a power

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every now and then. Oh, I know that sounds awesome. And so Amy, with your, so part of your research, as I understand it, is looking at the practices of dieticians as well and looking at how they might identify athletes at risk of low energy availability. Can you kind of talk us through that component of your research and some of the things that you've uncovered? Yeah, for sure. So I guess first and foremost, just in case there's anyone listening who might not be

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So that study looked at low energy availability or LEA as we referred to it. And so that often occurs when there's this mismatch between an athlete's energy intake and their exercise energy expenditure or their energy expenditure in training. And so when an athlete doesn't have the adequate amount of energy to support the training that's going on, we often see perturbations to a number of physiological functions.

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production thermoregulation and I know, noticed you had Jose Arita on who's an expert in this field. He's got an excellent paper and I don't know if it's the paper that you covered but with a diagram that and it's the diagram I always refer back to because it's got all of the hormones on it that are disrupted when you're in low energy availability and exactly what happens. Yeah and so that's it's excellent and I often refer back to that a lot. So I guess that's what our paper was

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okay, we know what low energy availability is and we know that sports dieticians or registered dieticians play a central role in managing low energy availability in athletes, but what kind of tools are they actually using to assess and manage athletes in practice and how effective might those tools be? And so the study that we did, we conducted it on 55 Australian sports dieticians

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the typical assessments of things like dietary intake, training load assessments, and assessments of menstrual function to identify athletes who might be at risk of low energy availability. And we found that, I guess, the more difficult measures to conduct on a day-to-day basis, so things like sex, hormone pathology, where you've got to go to a lab and get bloods and go see a GP or a sports doctor and get a referral and things like resting metabolic rate

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cart and you need the athlete to be ready to lay still for half an hour and be fasted and things like that. They were sort of lesser used by sports dieticians because they're just not as accessible to the sports dietician. And we know that there's a number of considerations that you need to take when you are doing these assessments. So, for things like resting metabolic rate,

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you need an athlete to be fasted, you need them to present really early in the morning. That often presents a lot of limitations for sports dieticians when they are looking at which tools are going to be the most beneficial or the most accessible or realistic for an athlete to use when they're trying to assess low energy availability. I guess for the most part, a lot of sports dieticians are using those tools that are more readily accessible to them,

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intake because it's easy to say to an athlete, okay, we need you to record your dietary intake for two to four days and jot down what time you're eating and sort of what you're eating. But we also know that there's a number of inaccuracies with those kind of records. So we know that, and there's a good paper by Ida Hikura that's been published that talks about the issues with dietary intake and training load assessments.

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And a lot of these assessments are often fraught with inaccuracies because there's a lot of under-reporting or over-reporting or it's simply just too difficult for the athlete to commit to recording their dietary intake for two to four days. We all know what it's like to try and sit down and remember what we ate or remember to enter something into an app or write it down. So I think there's a number of issues with some of those assessment tools and I guess that's what

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really interested in looking at was okay what's being used and what might be either the benefits of using those or all the limitations. Does anyone, is the leaf questionnaire widely used Amy? So that was another one that we sort of found wasn't really used by many sports statisticians and I mean we didn't actually ask sports statisticians why they didn't use it but

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we know that leaf cues only validated for endurance athletes. So, for example, sports dieticians working with team sports, weight making sports, things like that, sprint athletes, we know that the leaf cue hasn't been validated for those. Also, we know it's only obviously validated for female athletes. So, there's 50% or more of athletes that we're not capturing with the leaf cue. And so, I think, yeah, a lot of sports dieticians tended not to use

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use the leaf cue, you know, in favourite using things like dietary intake assessment and training load. And like I said, you know, using menstrual function to assess energy availability service was, was one that was widely used. But then how do we assess males, I guess, is another thing. Yeah. So, yeah. Yeah. And I think as well, it's sometimes if you, you have that really robust marker,

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energy availability is so much more than just the menstrual cycle. And I think that's a common misconception that, you know, females think that if they are getting their period every month, well, they can't possibly be in low energy availability. That's exactly right. Exactly right. And it's the same thing with changes in body weight. So, you know, a lot of the time, we might see an athlete who's in low energy availability, and they aren't necessarily dropping body weight. And so I think that's, and that's something that I think is really important to

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is that oftentimes you need sort of, I guess, a bit of a toolbox with a number of different tools that you can use to assess an athlete because you might test, and like you said, with menstrual function, you know, likewise with things like RMR, you might test their RMR, that might come out fine. You might look at their menstrual function, they're not menstruating. There might be hormones such as growth hormone or IGF-1 or whatever it may be, and they might be perturbed. And so then we might go, okay, well,

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got three things here that are leading towards a diagnosis of low energy availability. Yeah, RMR might not be showing that, but we've got a big sort of, I guess, pool of evidence here that we can use to support our diagnosis rather than if we had have just looked at RMR or menstrual function and that was fine, we would have marked them off and gone, yep, they're perfectly fine, but there might have been other underlying factors that we sort of haven't considered.

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with energy availability, unfortunately, there's sort of no one fits all tool. I think it's definitely, you know, we've got to use what we've got available and we've got to sort of use as many tools as we can to come up with that diagnosis. Yeah, sure thing. And of course, not everyone, like I'm thinking from an athlete perspective, not everyone is going to go to a sports dietician to get these kinds of things assessed. But there are certain things which, you know, if I'm an athlete

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then that might be a sign of low energy availability, despite the fact that I'm menstruating or, you know, so what are some of those other more qualitative things, Amy, do you think that people could be on the lookout for that, that might raise some red flags? Yeah, yeah, for sure. And I think this is definitely something that we ask sports statisticians in that same study. So we asked sort of what cues they might look for. And I guess that's the things that people can start looking for in, you know, if they are an athlete

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see a sports dietician regularly. So things like body awareness cues, so being aware of, you know, are you feeling really hungry? Are you really fatigued all the time? Are you getting injured more often? Are you finding that you're really sick and you've got time out of training? And I guess that's one of the really important things to look for is how often am I missing training sessions? Is that increasing? As I said, body weight's not always a factor, so that might remain stable.

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decreases in appetite, looking at training load and how that might be affected. Also, and this leads nicely into talking about CGMs, I guess, is that we know that blood glucose can be disrupted, well, normal blood glucose control can be disrupted as a result of low energy availability. Looking at some of the symptoms that might occur as a result of hypoglycemia or

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So we might look at things like that to prompt an athlete to go, okay, well, maybe I do need to go and see a sports dietician. Maybe there is something going on here. And another thing too, I guess, for males that we're starting to get more evidence around, and I know a dietician, Bronwyn Lundy, has done a lot of research. She works for Rolling Australia, but she's done a lot of research into low energy availability in

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I guess one question that's sort of come out of her research that's really important to ask males is, you know, what's their libido like? And so I guess that's kind of the counteracting question to are you menstruating for females? So that's another thing that males I guess could be on the lookout for if they've noticed that their libido has decreased significantly that might be a sign of low energy availability. You know, it's such a good point.

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to talk about the periods, you know, talk about the menstrual cycle and stuff. That's it. I wonder what the conversation around libido and how normal I, and I think that's the next obvious step, right, that we don't really often talk about because, you know, usually low-end availability is sort of, has in the past been in that female camp and it's only been in the last few years that it's, you know, acknowledged a male endurance. Yeah, that's exactly right. I mean, it's, we've come from the female athlete triad, right?

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we didn't even consider that this would be a thing that could happen in males. And I think, again, this is another question that we did ask in the study was, well, how often do you ask males about their libido? And it wasn't frequently asked. And I think it's just, you know, it's similar to what you just said about how far we've come with with asking about periods and that being sort of the normal part of the conversation, I think at the moment, because it's such a new concept, a lot of us aren't super comfortable with saying, OK, you know,

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how's your libido going? You know, and you know, my PhD supervisor, Greg Cox, or Coxie as he's known by lots of people, he sort of says to males, oh how's your morning wood? And I think he, you know, he's so personable and also he's male, but he can kind of get away with that. But I think, you know, us as females, it's a little bit more difficult for us to ask

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Yeah. And so I think it's definitely something that I guess we need to work on and become more comfortable with. Totally. Like anything. But yeah, I think it's just because it's still a new concept, I think it will take us a little bit of time. And that's exactly what we've shown in the study that there's lots of people who aren't asking that. And I think it's just from a, A, it's a new concept and B, it's just something that we need to become more confident with,

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where, you know, we are going to see male athletes, you know, 50% of the time or whatever it may be. And I think it's just becoming more confident and comfortable and having your own way of maybe asking that question that you feel comfortable with. So yeah, yeah, no, that's such a good point. And I think even us discussing it here will sort of pick the interest of people who, you know, male athletes themselves or other practitioners

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sure. Yeah, yeah. Yeah, yeah. I think bringing it up as often as we can is definitely a good thing. Yeah. So Amy, you mentioned CGMs, which is something which I'm super interested in. And it feels like, for whatever reason, and this is, you know, I obviously I'm not in the research space with this at all, but I've got a professional interest, but it feels like it's quite contentious, actually, continuous glucose monitors in the use outside of a sort of diabetes specific condition.

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Look, I've had, I've talked to people a couple of times on the podcast about continuous glucose monitors, but I would love for you to, to first and foremost, give us a refresh on what they are, what they do, what they use for. Yeah. So, um, as you mentioned, continuous glucose monitors have been historically used in, in, um, individuals with diabetes to monitor, um, blood glucose. So what CGMs are, is there a minimally invasive device?

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tissue. So, we usually attach them on the back of the upper arm. Some can be attached on the stomach or the lower back. Just depends on the device and where it's been approved for attachment. And what it does is it measures interstitial glucose and then it uses a calculation to estimate what that would equate to in blood glucose concentration. And so, these devices have been validated and compared against the gold standard for blood glucose.

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concentration. And we know that in diabetics, they are pretty, pretty accurate. So within 10% of estimating blood glucose, and there's, there's also actually been one paper done by Felicity Thomas that looked at the accuracy of the men athletes. And it's actually been found that they've been pretty similar to diabetics, actually, if not a little bit more accurate, um, in estimating blood glucose concentrations. And so what CGMs essentially do is they sit on,

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or arm. They allow us to look at the duration, magnitude and frequency of any glucose fluctuations that might occur during the day. And then they provide this back to the user in almost real time. So the athlete who's using it downloads an app onto their smartphone. All they have to do is swipe their smartphone over the device and their blood glucose reading is right there for them to see.

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specifically for athletes. Unfortunately, also over here in New Zealand and Australia, they're not approved here. Now, is that Super Sapiens? Yes. And that you're thinking of? Yes. So, yeah. So Super Sapiens uses a specific device called the, I think it's called the Abbott Sports Biosensor. So also developed by Abbott, which is a diabetes care company. But the difference between these devices and the diabetic devices is that these use Bluetooth.

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and usually have to swipe every eight hours to keep the data in the bank. Otherwise it'll start sort of chopping off data. So you've got to swipe it every eight hours. The benefit of super sapiens is that it's all through Bluetooth. So there's no you still need to swipe every eight hours. But as soon as you open that up, you can see your blood glucose without having to swipe. And you can see that consistently. Those devices are also a little bit different to the diabetic ones where they've got sort of a shorter range of glucose

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you just for the purposes of athletes maybe misdiagnosing themselves. So they just want to prevent that. But us so far, we've used the diabetic monitors because they are very similar. I'm just because it's hard for us to get them here. But yeah, as I've essentially in a nutshell, the CGMs allow you to sort of see your institutional glucose, an equation to transfer that over. And then that's downloaded straight to your phone. The device is usually

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about 14 days, that's how long the other sensors last. And yeah, swiping, you can see all of your data there. You can see like your glucose patterns, you can see your average glucose over the day and any hypoglycemic episodes that might occur during the day. So Amy, before we get into the nuts and bolts of your research and your athletes and what, and you know, the potential limitations or the usefulness of it, clearly, obviously you've used one before. Yep. I've used about six.

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surprises? Like, were you like, what the heck? Uh, not really myself. No. I have, I have, so my supervisor, and he'll probably kill me for saying this, but he has won a few as well. He was going into a lecture and his glucose spiked right up to about 13. Stress response, obviously. He said, I think I'm going pre diabetic. I said, I think I

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point but we'll just keep an eye on it. But no, myself, no, I mean it was the benefit of me wearing them myself was just to learn I guess the experience of wearing it and see what it was like. I mean I still swim quite a bit and I wanted to test out what it would be like in the water because they haven't really been tested a lot. Obviously you know individuals with diabetes can wear them in

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when people have been swimming and to be honest, I found no real problem with it. So it was a good experience for me, but yeah, unfortunately my data wasn't overly interesting. So I've used one before and in fact, talking to you reminds me I've got two more in the garage and I'm like, oh, might pop that on after this. Yeah, yeah. I had these protein bars which I do love, they're called No Cow Protein Bars and they're, I don't know, they're vegan,

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and they have a type of fiber in them that means that the net carb is maybe two grams. Yes. I ate one, totally spiked my blood sugar, which because, and then I did a little bit of investigation and I want to say, I've seen it before in the podcast, I think it's like the isomaltoligosaccharide or something. It's something like that. But it is known to do that,

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I found that very interesting. What people assume is going to happen with their blood sugar isn't always necessary the case. And it might not even be the case every time they have a particular food either, given other sort of conditions. Yeah, that's exactly right. I think that's something that, and I know we're going to talk about the limitations a little bit later on, but I guess this is something that we need to be considerate of when we are using CGMs is that

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influence glucose homeostasis. And there's a number of important factors that people need to consider when they are using CGM. So it's not just as simple as, you know, you swipe your device, you get your glucose, you might've eaten some carbohydrate, your glucose spikes, like it's not always that simple. I think there's a number of complexities that are associated with these interactions that we see. And, you know, whether that be someone's ingested

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exercise and they get a post-exercise hyperglycemic response. Maybe someone's got individual glucose fluctuations that occur depending on the type or intensity or duration of the exercise that they're doing. Also depends on the athlete's carbohydrate availability, their energy availability and circulating systemic glucose as well. So these are all going to influence the circulating glucose

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that the circulating glucose concentration isn't always reflective of the glucose that's being released through the gastrointestinal tract and subsequently the uptake into the tissues, like the muscle and the liver. So I think there's a number of different considerations that we need to take into account when we are using CGM devices. And I guess this is what some of our research has shown is that it's really important to understand what else might be going on when

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because, yeah, oftentimes, unfortunately, it's not just as simple as putting one on and there you go. There's a lot of underlying factors, yeah. So Amy, what can we use these for then? I mean, apart from the obvious, measuring glucose, so what are some of the benefits of knowing this information? Yeah, so I think the first thing that's really important to note is that at the moment, we know that the application of the glucose monitors

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untested. But as I've mentioned, these companies have come out with these sport-specific devices. To date, there hasn't been a whole lot of research to support these devices that have come out, but we do know that there are a small number of studies that have investigated an athlete's glucose response to carbohydrate ingestion. A lot of these studies have looked at

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multi-day endurance event to monitor what happens during that event to an athlete's glucose following ingestion of carbohydrate. Now these studies have sort of had mixed reports so either the CGM has been able to provide us with an indication of what's going on or there's sort of been a discrepancy between okay the athlete's eaten this much carbohydrate and it hasn't really been accurately

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that feeds into all of those background things that might be going on with glucose homeostasis that aren't taken into consideration by the CGM itself. I think for us personally, we have looked at potentially using CGMs as a bit of a tool to investigate fueling strategies that are used by athletes around exercise and during exercise and also as a tool to potentially

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The reason that we're looking at that, and I guess this feeds into what I said at the start is that we know that reductions in fasting blood glucose can occur as a result of low energy availability and we know that this happens in about five days. We don't know, there hasn't been a lot of research to investigate whether this happens more acutely. So whether we see that over sort of 24 to 48 hours. But I guess the benefit of CGM technology is that we're able to see everything in relatively real time.

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well, we've got this tool that can show us what's happening in real time. Well, can it potentially identify things like low energy availability or suboptimal fueling on a day-to-day basis? And can we then address that in more of a real time sort of scenario rather than waiting to further down the track when we see disruptions to menstrual function or bone density loss? Can we identify problems with an athlete's fueling status, you know, before that sort of occurs? But

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the moment we're sort of in the really early stages of researching that. And I think, you know, I think at the moment there's relatively limited, limited evidence to support the use of these in sport. And so I think it's, this is why it's really important for us to talk about this, this topic and, and research this further to sort of get some evidence behind it. Yeah. Okay, Amy, cause I, yeah, I'm really interested in that sort of the application of it to determine sort of fueling strategies and things like that. I believe that I've

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out there on maybe it's Super Sapiens social media or in other media that very good runners, like world-class runners have used this information to help them determine whether they eat before a race or what they do during a race. Can a CGM actually determine that or is that the stuff that we are still trying to figure out? Yeah, so I know I think you're probably referring to

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who's worn it. Yeah. And there's also a Blominfeld, the triathlete who's also worn it Christian Blominfeld. But, and so they have been marketed on the website as having worn them. But again, as I've mentioned, and I think SuperSafety Means talks about this optimal glucose range, which you know, there's just, there's not a lot of evidence to support that. I think,

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we can look at an athlete's blood glucose values and go, okay, is the athlete running low? If they are, then maybe we need to increase their carbohydrate intake. But there's not a whole lot of evidence at the moment to really support, okay, if you sit in this optimal glucose range, you're going to perform better. And I think that's where we really need more research to support

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athletes are wearing CGMs and how their fueling might influence that and build a bit of a bank of research because there's just, because this is so new, there's a lot of research in diabetics, but there's not a whole lot in athletes. Yeah, sure. And then you mentioned that looking at during race fueling, and there might be discrepancies with regards to, like for example, a gel every 20 minutes, but that's not showing up when you're looking at

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happening? If you can't see that 25 grams of glucose in the bloodstream, what's happening? Yeah, and I mean, I think it leads into, yeah, it's sort of what I spoke about before. I think there's, you know, it depends on the individual athlete. I think there's a lot of different factors that can influence that and how an athlete might uptake that glucose. We've been doing a lot

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at energy availability and using CGMs at the same time. And what we're really interested in, I guess, is just that is looking at, okay, if an athlete has a low energy diet, and they take in a whole amount of glucose, so we've actually been using oral glucose tolerance tests, which are used to diagnose diabetes. Yeah, so they've got 75 grams of carbohydrate in them. So if someone's in a low energy diet, and then they consume that oral glucose tolerance test, is there

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body then just sucking up that glucose and we don't see it in the blood? Or does the opposite happen? And I guess that's something that we don't really know. So that is something that we've sort of been really looking into. I mean, our most recent study is looking at, okay, based on an athlete's energy intake, does their response to an intake of a high amount of glucose, does that change based on the energy status of that athlete?

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That's super interesting because I know that low carbohydrate, also women, for example, who are pregnant, then they have the OG oral glucose tolerance test. Yeah, yeah, there's that insulin resistance. That's right. Yes. Yeah. So that's, I guess, one thing that would be super interesting to see what happens there. Yeah, yeah, for sure, for sure. And I think, yeah, I think, like I said, it depends on the individual athlete.

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they're more adapted, I guess, to fat and oxidizing fat. Potentially, we might see blood glucose uptake into the muscle and use of glycogen. We might see a reduction in that. But again, depends on the individual athlete. I think it's really cool that we're looking at that and seeing how might their response change in response to different habitual dietary intakes.

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Is that something that you're actually looking at at your research currently, or is that like sort of postdoc type stuff? Yeah, so I mean, postdocs definitely on the horizon as well, but at the moment we are looking at that. So we're kind of looking, it's kind of, I guess, a bit of a sub part of my current study. So at the moment we're looking at the effect of altering energy availability on CGM measured whole body glycemia. So in trained athletes,

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at, well, if an athlete is in low energy availability for a 24 hour period, what does their blood glucose do? So, we're monitoring their glucose with CGMs across the day and then into the night. The reason why we look at nocturnal blood glucose is because we think it might provide a greater insight into these changes in glucose metabolism because as we've talked

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And if we can potentially remove two of the biggest influencing factors during the day, exercise and diet, and we look at glucose overnight, we might be able to more clearly see what might happen if an athlete is in a different energy status. So, my study is looking at putting an athlete into low energy and then high energy and comparing, okay, well, what's actually happening to their blood glucose in real time if they're on a

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period. And the reason why we've chosen a 24 hour period is because we really want to see, well, can these devices tell us acutely what's going on before we start seeing perturbations to other hormones and things like that. And then yeah, a subset of that study, I guess, is looking at their response to that uptake of a high amount of glucose and seeing what happens there. Yeah, super interesting. It would be interesting to look at urinary sort of cortisol across

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glucose and that as well to see what you might, what relationships we glean there. Because of course, stress, as you've mentioned, really potentially impacts, it would be nice to be able to see that. That's exactly right. And we are measuring a number of different hormones, I guess. Cortisol, unfortunately, is not one of them, because we just don't have the budget for it. But we are looking at a number of other markers like IGF-1 growth hormone,

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Garelin to see because they're acute markers of energy availability. So seeing, well, are they actually perturbed after 24 hours or does it take a little bit longer? And then additionally to that, we're also looking at the CGMs comparing those to capillary glucose and then comparing those to plasma glucose to see, well, how accurately is the CGM actually telling us about blood glucose because it's making that estimation, I guess.

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the criticisms I've seen of CGMs is that they lag or something behind what might actually be happening. And it's like, how meaningful is that lag? I mean, it might be significant in a study, but is it actually meaningful in real life? Yeah, and you're exactly right. So they lag about 10 minutes behind actual blood glucose. And I think that that's definitely a consideration that people need to think about because, you

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okay what's going on but in the actual fact it's 10 minutes behind what you're actually looking at yeah and that's something that we need to be considerate of so yeah and i've often wondered that with that sort of in fueling aspect of using cgms is one the lag but also as an athlete you know as a runner i know when i need fuel like i don't like i wonder i wonder what the timing would be like compared to me feeling low blood sugar and maybe something would have sort of

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indicated to me on a CGM 10 minutes earlier or 15 minutes earlier that could have prevented that, but I do wonder about the timing of feeling low blood sugar versus what I might see in a CGM as well. Do we know that? Yeah, look, I think, again, I think the answer sort of depends on the individual. I think there's some individuals that might experience those symptoms before they notice that on a CGM, but I think there's also other individuals who might not experience those symptoms that are

40:28
to say a hyperglycemic event. So they might not experience fatigue or tiredness or that real hunger. So I guess in those cases, that's when those devices might be more useful for someone when they don't experience those symptoms. So without the CGM on, we might not know that that's occurred. And so getting that information would be beneficial. I also think, and depending

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how closely we're monitoring the CGM, oftentimes you can kind of get an idea of the direction in which the glucose is going. So in the next 10 minutes, you know, if your glucose is going down and it's at three and you can see that it's trending downwards, you know that you're gonna have a hypo. So I think being able to look at the data and know what's happening when you wouldn't otherwise know is beneficial.

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research, unfortunately. Yeah, which is awesome, Amy. Like how great to be part of a project where you start off by saying, we just don't know, we just don't know, we just don't know. Whereas in five years time, I could be having this conversation with someone else and they've been informed by the research that you're doing, which is really cool. Exactly. Yeah. And it is really cool. And I know that there are some other PhD students in Australia that have started and I'm sure there's some across the world as well, because this topic has just become so topical.

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since I started my PhD and it's just, I think it's, yeah, everyone is interested in it. I have people contact me all the time, sports statisticians in Australia saying, can we talk to you, athletes wanna wear one? And so I definitely think this area is only gonna get bigger and there's only gonna be more research done into it. And I just think it's great. I mean, yeah, the more research we can get in this area, the better. And I think it's a great technology.

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and if it works, then that's great. But yeah, I definitely think the more research we can do in this space, the better. Yeah, for sure. And then finally, Amy, you touched on it a bit briefly, but what about a fat adapted athlete? Like, you know, the low carb is there because I've seen data from people, and I want to say exact better, but it might not be but you know, where his glucose has gone very low, but he's actually really fine. And so that's indicating

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that hyperglycemic event or do we know anything about that? Yeah, I mean, I think that's a good question. I think, you know, when an athlete's at rest, there's probably not going to be much of a difference. But as I sort of mentioned, I think, you know, we might see a reduction in that blood glucose that's being taken up into the muscle and the use of that glycogen as a fuel, we might see a reduction in that in a heavily

43:28
So, we might see a difference in the maintenance of glucose readings, at least at submaximal exercise intensities. But again, I think there's definitely another space we can do more research into. But I think there is potential there to see some sort of differences. And I guess, again, that's sort of why we need to err on the side of caution when we're looking at

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to be different. And I think, yeah, someone who's heavily endurance trained might show a different response. Yeah. And it's, you know, it's, and of course, the last argument that people come up with is, and I don't know which camp I'm in, because I do like data, but whether or not I use it as a different story, you know, but I know there are people who are complete data heads and so they've got their work, they've got their aura, they've got training peaks, they have their HRV measurement, and now they've got their CGM, like, and it's, they're measuring so much that they're

44:28
and going, how do I feel today? You know, and it's, you can't always use your intuition, I guess, either, can you? Because sometimes you can feel rubbish, go out and have a good swim or a good run, and you're like, actually, I feel so much better and I would never have picked that. But, you know, is it possible that we just, you know, are just over data collecting? Yeah, I think that's possible with any sort of technology. And I know, I can't remember who it was, but someone termed it as glucorhexia.

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So that's the term I've heard. And I was like, oh, that's, yeah, that's an interesting one. But I think like with anything, you know, too much data can always be a negative thing. I think for the most part, I think you've got to be careful. And I know as a sports nutritionist, you know, I'm always careful who I'm putting these devices onto. I think for someone who's going to become obsessive over the data, it's not going to be that helpful.

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for someone who is just interested and, you know, they sort of like data and they like to see what's going on. I think it could be useful, but I definitely think as with anything and any technology, there's always the danger of falling into becoming too data-driven and like you said, not being able to identify things for yourself because then if something does become problematic, you might not notice it. And as we know with technology, it's never foolproof.

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interesting thing that I've noticed in my experience with these devices is that I've had some athletes wear them and they'll say to me, oh, like I've just eaten 60 grams of carbs and I'm going into a hypo. And I'd sort of say, okay, well, like that seems a bit strange. Go away and see what it's like in 15 minutes. And they'll come back and they'll say, no, it's still dropping. And what I've actually learned about that is it's the CGM coming out of the subcutaneous tissue and it's reading a false hypo. And so what that

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really dangerous for is people who are, you know, don't, aren't sort of standing back and going, okay, what, this is strange. What's going on here? And then they start going, Oh no, I'm in a hypo. And you know, it's not going up and what's going on. And really just out of experience, I'm able to say, well, it's actually not a real hypo. That's just a new place to device. And their glucose is fine. So I think, yeah, as with any technology,

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to be errors and it's not full proof. And I think it is still important to be able to identify and have that insight into what's actually going on. Because like I said, there's times where you might see some data and it might not make any sense and you need to be able to go, okay, well, am I actually feeling like I'm in a hypo? Maybe I'm not, you know? So I think that's, yeah, it's a risk we've run with any sort of technology, I think. And I think with these devices, the best thing to do is to be really targeted with when we're

47:28
them. So, and I guess that's what our research is interested in looking at energy availability is how can we use them in maybe a more acute setting having an athlete wearing them for a day or two days or three days to look at their energy availability status rather than wearing one continuously. And I mean, that's something we need to be, I guess, mindful of is that these devices aren't cheap either, you know, that they're $100 a pop, they last for two weeks. So that's all the

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targeted with when we are using them. Yeah, yeah, nice. Amy, thank you so much. I really have enjoyed this conversation. And I just think it's such an interesting area that a lot of people will be waiting with bated breath for the publication of further studies. How far down the line can we expect more papers from you and your research? Well, hopefully by the end of this year, we've got another paper that will shortly be coming

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looking into the day-to-day variability of glycemia in endurance athletes. So, what do we expect sort of on a normal day-to-day basis to see in the fluctuations in glucose? And the reason why we did that study was to get a bit of an indication, okay, well, if this is what it looks like normally, then what is it going to look like when an athlete's not feeling adequately? So, hopefully, that will be coming out soon. And then we're sort of trying to, I guess,

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some of this study that's looking into the intervention and looking at low energy and high energy and so fingers crossed that will be out by the end of the year. Amazing can you give us any insight into that first one that's almost published? I wouldn't say it's almost published, I'm still trying. But we have seen that we know that the glucose fluctuations that occur across

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healthy individuals. So there's been a few studies that have been done that have looked at CGM use and normal blood glucose fluctuations in normal individuals, so those without diabetes, and so the results that we've seen have been relatively similar to those. Okay, okay, well that's interesting. So, well we look forward to that. Amy, thank you so much for your time this morning. I really appreciate it and I will put links to your current published papers and of

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profile as well just in case anyone wants to reach out. Although it sounds like you're pretty busy with all of the dieticians across Australia contacting you but hey you'll get such an interesting topic I'm not surprised at all. Yes thank you so much for having me it's been great.

50:26
So that was such an interesting talk to Amy about CGMs and glucose utilization. And of course it seems that a lot of the claims for its potential benefits are, at this point in time, a little bit hyperbole compared to what we actually know. Which is generally the case really isn't it? However it's worth noting that glucose metabolism for an athlete and non-athlete is an important part of the performance puzzle.

50:56
how this research progresses over the course of the next couple of years. So I'm super excited for Amy and what she's got planned. Now, because we are talking about athletes in general, it seems like a perfect opportunity to remind you that one way you can help both performance and recovery is currants. That black currant supplement created from New Zealand black currants that has clinical research to support its application in the sporting performance setting.

51:26
you guys will know I've chatted to Fleur a couple of times on the podcast before and she is the co-founder of currants as a supplement that the way that the black currants are produced in New Zealand really enhance the antioxidant properties of the black currant so it's super cold winters super hot summers that is a secret source to the black currant supplement currants.

51:56
You might not know that Curranz very recently won the Sports Nutrition Product of the Year at the Nutri Ingredients Europe, Asia and USA conferences, that people is the triple crown, and it also won the Marquis Award at the Europe Specialist Sports Nutrition Alliance Awards in December, and last year began a collaboration with Healthspan Elite who was the official sponsor of

52:26
Curranz in their armour of supplements and really rate it, and there are just human clinical trials to support its use with regards to performance and recovery, and this is one of the reasons why I also choose to include it in my everyday supplement regime. I'm not alone though, we've got Ruth Croft, Anna Fruss, Sean Collins, a whole bunch of other people in the running community, and that's

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the audience that Curranz reaches. So if you want to try Curranz, use the code MIKKI in capitals, that's M-I-K-K-I, to get 25% off your first order, and that is at Curranz website www.Curranz.co.nz and we will pop links to that in the show notes as well. Alright team, so that's it for this week, and until next Wednesday you can find me over

53:26
Facebook at Mikki Williden in nutrition over on Instagram and Twitter at Micky Willard in or head to my website Micky Willard in comm where in addition to signing up to a number of my fat loss or sports nutrition meal plans you can book a one-on-one call with me alright team till next week see you later