Episode 33 - Iron & Endurance Performance with Rebecca Hall

Iron & Endurance Performance with Rebecca Hall

Do you feel tired, lethargic or fatigued and are not sure why? Maybe you need to get your iron levels checked.

Inside the Triathlon Nutrition Academy program, we talk all about Iron and how important it is for endurance training. I want to make sure my athletes know how to recognise symptoms of deficiency but also how to fix it, quickly.

Joining me in this episode is fellow Advanced Sports Dietitian Rebecca Hall aka Beccy. She has recently submitted her Masters in Iron supplementation for endurance athletes travelling to altitude with the goal of increasing haemoglobin mass.

She is well across the research in this space but is also excellent at translating that deep science into something practical and easy to understand. 

In this episode we talk about…

  •  Why iron is such an important nutrient for triathletes
  • Where you find iron in your diet (hint: it’s not just red meat!)
  • Advice for vegan and vegetarian athletes to meet their targets for iron intake without eating meat
  • The variable bioavailability (how much is actually absorbed by the body) or iron and tips for how to enhance iron absorption
  • Do we need to take a supplement?
  • Plus tips for how best to manage your iron


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Episode Transcription

Episode 33 - Iron & Endurance Performance with Rebecca Hall

Welcome to the Triathlon Nutrition Academy podcast, the show designed to serve you up evidence-based sports nutrition advice from the experts. Hi, I'm your host Taryn, Accredited Practicing Dietitian, Advanced Sports Dietitian, and founder of Dietitian Approved. Listen as I break down the latest evidence to give you practical, easy to digest strategies to train hard, recover faster and perform at your best. You have so much potential, and I want to help you unlock that with the power of nutrition. Let's get into it.

Taryn Richardson  00:44
Today's episode is with Rebecca Hall. She's a fellow Advanced Sports Dietitian who I had the pleasure of working with at the AIS (Australian Institute of Sport) down in Canberra many years ago. She recently just got back from the Beijing 2020 Winter Olympics, which is pretty cool! And works with the Olympic aerials, snowboard, slope styles and alpine skiing, as well as our Paralympic Alpine skiers and snowboarders. Talk about a dream job. And I've asked her to jump on the podcast with me today to give us a bit of a rundown on iron. 

Taryn Richardson  01:12
She's recently submitted her Master's in iron supplementation for endurance athletes travelling to altitude with the goal of increasing our Hb-mass or hemoglobin mass. Now you don't really need to know what that means. But all you need to know is that she spent a lot of time reading the literature on iron. And she's really good at translating that into practical things. We're not going too deep today, I want you to get just a really basic understanding of why iron is important for you as an active person, some of the places where you can get it from your diet, and what it means in terms of the bioavailability. Because iron is a bit of a complicated mess, to be honest. It's not as simple as eating an iron-rich food like people think steak is, you know, rich in iron. But what's actually in that food doesn't necessarily all get digested and absorbed. 

Taryn Richardson  2:02
So she's got some really great tips for you, as an active person, on how to manage your iron. And if you want to go deeper then it's one of the topics we talk about in phase one of the Triathlon Nutrition Academy program. It is part of building our day to day nutrition that we spend eight weeks on right up front because iron is so important. And because it's something that you'll probably need to be on top of forever. As somebody that pounds the pavement and does a lot of exercises where we need oxygen to transport around our body effectively. But I'll hand it over to Becky, she's the expert, she can give you the rundown on iron, and what you need to be doing to make sure you're getting enough.

Taryn Richardson  02:47
Alright, welcome to the podcast, Becky!

Rebecca Hall  02:50
Hello, thank you for having me.

Taryn Richardson  02:52
I'm so excited to have you - got fond memories of skiing with you overseas. But this is a new realm for us talking on a podcast together.

Rebecca Hall  03:00
It is indeed! It's very grown-up compared to skiing. But it’s great.

Taryn Richardson  03:04
So I've got you on today to give everyone a bit of a rundown on iron. I find iron can be quite complicated. People don't kind of understand the importance of it, where to get it from their diet and how to make sure that they're not iron deficient. And you are the master in iron. So there's no better person to talk about it, than you.

Rebecca Hall  03:23
Look, I'll take that! I've definitely done a lot of research and I'm more than happy to talk about it. And I think it's one of those things that we hear lots of bits of information so that can make it even more complicated. So hopefully today I can make it a little bit easier for people to understand.

Taryn Richardson  03:36
Thank you. So let's get the ball rolling. Why is iron such an important nutrient for active people?

Rebecca Hall  03:43
Well, it's especially important for active people because iron plays a really big role in actually transporting oxygen around the body. So it plays a role in both hemoglobin and myoglobin, which are basically the transporters of oxygen around the body. So if you think about exercise, especially more cardiovascular type exercise, that's going to require oxygen to actually complete. So without that oxygen being transported around the body, it's going to be a lot, lot, harder to do those longer workouts.

Taryn Richardson  04:11
Okay, so if somebody is exercising and they're needing to breathe, then they need iron to do that?

Rebecca Hall  04:15
So yes, their iron plays that key role in building hemoglobin/myoglobin, which carries the oxygen around. So basically, think about it as the transport vehicle. So, iron plays a role in creating the taxis that carry oxygen around the body. So from the organs to the working muscles - so the body can actually get that oxygen.

Taryn Richardson  04:36
I love that analogy. I've never heard that one before - that one's a good one. Yeah. Now, most people know that you get iron from red meat. But there's so many other sources in our diet that we get iron from. Where else can we find it?

Rebecca Hall  04:48

It depends where you live in the world, but certainly in Australia, for example, we have a lot of iron-fortified cereals, which is actually a really good source of iron for people who don't eat red meat. It's also found in things like nuts and legumes and different vegetables and other meats as well. So not just red meat, there's also some in chicken. Eggs is a great one as well, a good source of iron. But what we perhaps need to talk about further on in this podcast is not all of that iron is absorbed in all of these foods. So that's why red meat is promoted as a great source of iron.

Taryn Richardson  05:22
So it's more bioavailable than some of those other sources.

Rebecca Hall  05:25
Absolutely. And the body has an ability in terms of absorbing different types of iron. And the type of iron that is in red meat is very easily absorbed. So it makes it much easier for the body to get what it needs.

Taryn Richardson  05:39
Can you explain to everyone a little bit about the two different types of iron, our haem iron and non-haem iron?

Rebecca Hall  05:45
Absolutely. So haem iron is from animal sources, okay. And that comes in a form that is readily absorbed by the body. And it sort of comes in this complete package. So when we eat it goes through the digestive system, and it's readily taken up in the gut for absorption and then used as iron within the body. Versus non-haem iron - and that comes from non-animal sources. So plant-based sources of iron. And that's much harder for the body to absorb because it comes in this sort of, like, complicated form. So when we digest it, it readily forms complexes with other foods, eaten at the same time.  So if we are eating these non-haem sources of iron, they are much more likely to get trapped in the gut and pass all the way through our gut rather than be absorbed. This means we just don't get as much iron from those foods, even though there's quite a bit of iron in them.

Taryn Richardson  06:33
So what about for a vegan or a vegetarian athlete where they don't eat any haem sources?

Rebecca Hall  06:38
Well, I guess one of the important things to consider in that circumstance, is to make sure that you have plenty of these non-haem sources of iron in your diet. But perhaps also providing additional consideration for some of the other factors that both help to increase iron absorption of these non-haem sources. So an example of that might be vitamin C - so actually making sure that the person is getting adequate vitamin C, but they're potentially also including vitamin C rich foods with their non-haem iron sources. And I'm certainly not advocating here for supplementation, just literally finding foods that are rich in vitamin C, and co-ingesting them, will be one way to help increase absorption. 

Rebecca Hall  07:18
There's also another consideration for vegan or vegetarian athletes because obviously iron is very important. And if you aren't having those haem sources, then you do need to think strategically about how you're getting enough iron. The other thing to consider is that you don't want to be having a lot of foods that actually might inhibit iron absorption. And so there are a couple of things to consider. And one of those is calcium. Now, a calcium source that vegetarians might consume could be dairy. If someone's vegan, they're unlikely to be having dairy. But even if they're having things like a lot of almonds, which can have some calcium content to it - just being aware that that calcium will compete with the iron in the gut and form those complexes and minimise the amount of iron that's absorbed. 

Rebecca Hall  08:02
So just thinking strategically about increasing absorption by having foods, particularly with something like vitamin C rich foods. And then also trying to avoid eating your iron-rich foods with something that's high in calcium.

Taryn Richardson  08:16
It’s this big, complicated mishmash of stuff, isn't it? Kind of, not as simple as just eating iron-rich foods and it being absorbed? Because the bioavailability just varies so much. Do we actually know how much iron is absorbed from what we eat, like, compared to what's on the food label, say?

Rebecca Hall  08:34
So one of the challenging things about this is that there is quite a bit of individual variation when we look at the research, okay, but we don't need to dive into that. In terms of looking at ranges in terms of haem iron, so that's the meat or animal containing iron, roughly between, like, 20% to 30% is absorbed, versus we look at something like non-haem iron, and you've got between one and 10% absorbed. Okay, so it's a significant difference. 

Rebecca Hall  09:01
Now, there's an individual variation on top of that, because if we think about some of the factors that might inhibit iron absorption - we've also got another component as well, which is impacted by our hormones and our health and our immune system. Which is perhaps getting a little bit too complicated here, but to say that much, much less - so less than 10% of the non-haem iron, is absorbed. Which is really not a lot. So to make it really simple for vegetarian and vegan athletes, they just need to be conscious of including iron-rich foods almost every day, and making sure that that's strategically eaten in a way that doesn't reduce the amount of iron that could be absorbed from that meal.

Taryn Richardson  09:39
So somebody that's vegan or even vegetarian and has not a lot of animal products or no red meat at all, they need to be really diligent about getting enough iron in and making sure they're not blocking the absorption of that with other things that they're consuming with that meal?

Rebecca Hall  09:54
Absolutely. And obviously, this isn't an option for vegan athletes but for vegetarian athletes. I'd strongly encourage them to consider eating eggs. Eggs are a wonderful source of iron. So it can be a great one to include in your diet if you are a vegetarian.

Taryn Richardson  10:08
And so if somebody needs to have some vitamin C with their haem sources, or non-haem sources to help enhance that absorption, they don't need to go and drink a glass of orange juice, do they, Becky? They don't need to take a vitamin C tablet with their steak.

Rebecca Hall  10:23
No, they don't. I mean, that sounds disgusting. But certainly, it's about having within the realm of what is an adequate daily intake of vitamin C. So it might be that someone has, like, a handful of strawberries - that would be enough vitamin C. Or a kiwifruit, or, you know, it's having small amounts of vitamin C. It's not about supplementation, which is actually very large amounts of vitamin C in a compounded form. So it's really just that small amount in real food that helps with the absorption.

Taryn Richardson  10:52
And lots of different colours of fruits and vegetables too - not just sticking to the oranges and the limes and lemons which people think are high in vitamin C.

Rebecca Hall  11:01
Absolutely not. And like one of the things I love is to include raw capsicum. So that's another great one. And that works really well with your iron-rich foods. Especially if you're looking for a more savoury dish.

Taryn Richardson  11:11
There you go. So you don't have to drink a glass of juice with your steak guys.

Rebecca Hall  11:15
No, and please don't.

Taryn Richardson  11:18
For vegan athletes and people that don't have a very high iron intake, do they need to look at taking a supplement?

Rebecca Hall  11:26
It's never recommended to take a supplement if someone is, you know, who’s demonstrating they have an adequate supply of iron. So the first step would always be - go and speak to your GP and get your iron levels checked. And that's a really important component because there's certainly some people who might have conditions that might affect their iron levels. So first of all, go and get that checked. 

Rebecca Hall  11:44
Now, if someone is shown to be iron deficient, and they are vegan or vegetarian, then engaging with a dietitian around how they can improve their diet is then the next step. If they're already doing everything they can, in a diet sense, and they're thinking about what increases absorption - they're thinking about avoiding those inhibitors. They're also potentially thinking about the time in which they eat it. And that's probably the next level that we haven't yet spoken about. There is sort of a time of day that can somewhat help with increasing iron absorption, and that would be earlier in the day seems to be better in terms of absorption. 

Rebecca Hall  12:18
So that's something to consider as well. But in terms of supplementation, unless there's demonstrated deficiency, and those things have all been done in terms of what you can consume to improve your iron levels, then the doctor would guide you on a period of supplementation. Under no circumstances would we recommend someone take supplements for lifelong. Iron is something that the body isn't very good at getting rid of. We can't really get rid of it in many ways. And so we certainly don't want to be encouraging someone to take iron when they're not deficient. Absolutely, if someone is deficient, under the guidance of a medical professional, then yes, a short term timeframe of taking supplementation would be advised as long as it's monitored again, sort of within three months.

Taryn Richardson  13:03
I think it's also important to note there, that a general practitioner may not be that great at managing iron levels in an athletic population. We have different guidelines for people that are quite active, and a general practitioner may not be across that. So it might be something that you need to get guidance from, from a sports physician who's more aware of our athlete guidelines, so they can help better manage that. Because for somebody’s iron status that is very active and does lots of exercises and needs oxygen transported around their body to do that, we want to see their iron levels are way higher than somebody that sits on their butt all day long and doesn't do any exercise.

Rebecca Hall  13:39
Absolutely. In addition to that, I'd encourage anyone who is going to get their iron levels checked at their sports physician, to really discuss the other things that can also impact iron. So often we forget to talk about these things. And for women especially, periods are one of our major sources of iron loss and there are some studies to show that very active, so elite athletes and this particular study that I'm referring to, noted that there was a high incidence of heavy menstrual bleeding. 

Rebecca Hall  14:04
Now, that's obviously going to impact your iron balance. So I just encourage people who are going to get their iron levels checked, talk about dietary preferences to a small degree with a doctor, because that's important too. That will help them to understand and potentially refer you on to a dietitian if you're not already working with one. But it's important to talk about those other things that can impact it. So have you had any recent, heavy menstrual bleeding? Or is that something that's regular for you? Talk about that with your doctor. 

Rebecca Hall  14:30
Talk about if you've had any injuries, or even mention if you're a regular blood donor, okay? Because they're all things that are going to factor into the results that you see. Certainly, someone's just given blood, their iron levels are unlikely to be accurate in terms of a reflection of what their levels actually are. So just thinking about those components. The other thing I would encourage people to do when they're going to get a test is actually not to take their iron supplement on the day of getting tested. Because that can impact their iron levels as well. So it can give you a misreading. So just sort of missing out on that day that you're going to get tested, and then commencing or recommencing supplementation, if that's what you've been advised to do, after you've been tested.

Taryn Richardson  15:10
Is that enough time to, kind of, I don’t know, wash it out in a way? Just a day? Or do they need to do a few more days, Becky?

Rebecca Hall  15:16
I mean, I guess ideally 48 hours, but if someone's really low in iron, then that could be a serious lack of iron that they're missing out on. People can certainly miss out on getting that regular iron intake, because if you think about it, certainly the supplement doses are quite large. And so it's a considerable amount to miss two days. So 48 to 24 hours, probably depending on the size and amount that you're taking. If you're taking in the realm of 105 milligrams a day, which is one Ferro-grad C, then probably best to just miss one day.

Taryn Richardson  15:46
Can I ask you about the different types of iron supplementation? Not suggesting anyone supplements without advice - but I've noticed a lot of GPs have been suggesting people take Maltofer because it's meant to be absorbed differently and therefore give less severe gastrointestinal symptoms. A lot of people suffer from either diarrhea or constipation with their Grad C. And so it seems to be the path that they're all choosing at the moment. But I know a lot of the research is in the iron form that is Ferro-grad C, those ferrous sulphates? Is there any research in the type of iron that is Maltofer? And is it more effectively absorbed or the same? Or do we not know yet?

Rebecca Hall  16:23
I have to honestly say that I don't know yet. In terms of what I've looked at thus far, I haven't looked heavily or deeply into the Maltofer supplement. I do understand that it is recommended for that lesser impact on the gastrointestinal system. It's an interesting idea around it potentially being absorbed differently, I think it's more that there's remnants of iron that remains unabsorbed in the gut. 

Rebecca Hall  16:47
So if you're taking a really large dose of Ferro-grad C, for example, then there is still going to be a percentage of that iron that isn't absorbed in the same way that if you eat some red meat, or if you have some non-haem iron, so plant-rich sources of iron, there's going to be iron that isn't absorbed. Now if you're taking 100mg of iron in comparison to maybe the 5mg of iron that was in your steak, that's a lot, lot more. So there's a lot more that's going to remain in the gut unabsorbed. And so the thought is that that iron remaining in the gut is actually interacting with microflora and bacteria in the gut. And that's what sort of causes some of the GI issues. So potentially, if there's a different absorption, that they may not be having the same with the remnants of iron - but I think we need further research before we can answer that one properly.

Taryn Richardson  17:35
Yeah, nice. I haven't really seen many studies, testing with Maltofer. Is there any coming out now?

Rebecca Hall  17:41
I haven't seen any. But that's one of the sad things about a lot of iron supplementation is often it comes back to who's doing the research. And that's not to say there's people pulling strings. But iron deficiency is a problem in athletes. Absolutely. But it's first and foremost an issue for women and children in developing countries. And they don't want to pay the excess bling, or excess dollars, for the fancy supplement. They will take whatever they can get access to at the lowest cost. So a lot of the research is done in the most basic and cheapest form of iron that can be produced but is safe for human consumption. That's my understanding and reading of literature is that, really, the priority for those who need iron are those women and children in developing countries? So that's why we haven't seen all the research in Maltofer.

Taryn Richardson  18:27
Yeah, nice. Kind of leads nicely into our high-risk groups, which you've already just mentioned. So females who have those regular monthly losses, growing bodies - is there anyone else that we need to really be mindful of that is a high-risk group for having low iron?

Rebecca Hall  18:41
Well, yes, I think we also need to think about those who potentially are more at risk of injury and/or surgery, where there might be some associated blood losses. Certainly for those endurance athletes who train multiple times a day and have a long duration - there seems to be an increased risk of iron deficiency in that population. And part of that is the background response to that actual training. 

Rebecca Hall  19:04
So there is actually, in fact, a response from what we call hepcidin. So that's basically our peptide hormone that's released. And it's released in response to exercise. And it actually reduces someone's ability to absorb iron for the following 24 hours. So if an endurance athlete trains twice a day, and they do that multiple times in a week, they're really reducing the windows within which they're likely to be absorbing iron at the fastest and greatest rate. 

Rebecca Hall  19:33
So those guys tend to be more at risk. And also, we know that, from studies that have been coming out, I mean, it was formerly referred to as the female athlete triad, we now you know, sort of talk more about RED-S, which is Relative Energy Deficiency in Sport. There does seem to be a link between those who are insufficiently fueled, in a more chronic manner - so low energy availability. So not eating enough for the amount of training and normal bodily functions over a consistent period of time. That seems to be associated with that increased risk of iron deficiency. The exact pathways and mechanisms of that being linked, haven't yet been determined. But it does seem to be more of an issue for females. But that doesn't mean it's not an issue for men as well.

Taryn Richardson  20:16
I don't want people listening to think that it's all dire straits and everyone's iron deficient. There's definitely high-risk groups - heavy menstrual losses, vegan athletes who don't have a very high intake of iron, anyone that's pounding the pavement and doing lots of training, which is probably everyone listening to this episode.

Rebecca Hall  20:32
Also women who have had pregnancy or are pregnant and returning from…

Taryn Richardson  20:38
Building another blood-sucking human?

Rebecca Hall  20:40
Yeah, and creating a, you know, incredible brain that takes a lot of iron. Absolutely, considering those things as well.

Taryn Richardson  20:47
So for the triathletes that are listening, Becky, what can they do to best manage their iron moving forwards from today?

Rebecca Hall  20:52
Well, I was gonna say choose the rest day, but with triathletes, it's a bit of a hard one to find. But if they have a rest day in the week in their regular training plan, try and prioritise that as a day to consume those iron-rich foods. So if you're a meat-eater, consuming red meat, if you can on those days, because that's when you're best likely to be able to absorb so I used to recommend like the Sunday roasts, like a lunchtime Sunday roast if you can, because it's earlier in the day, it's red meat. It's fabulous. And it's a rest day.

Taryn Richardson  21:22
Triathletes don't rest on Sunday. Triathletes do their biggest training on the weekend generally if they hold down full-time jobs.

Rebecca Hall  21:28
Absolutely don't do Sunday! Whatever day.

Taryn Richardson  21:31
Monday roast!

Rebecca Hall  21:32
Monday roast, if you can. Or even maybe you make some nice Shakshuka for breakfast on a Monday or something - that's got a bit of mince in there, some eggs and tomatoes or something like that. So prioritising those iron-rich foods on your rest days. But that's not to say that you shouldn't be eating red meat throughout the week. Absolutely try and include different forms of iron throughout the week. And if you're having those non-haem sources of iron, then try and make sure there's some vitamin C in there.  

Rebecca Hall  21:57
So a simple way to deal with this, is you know, buy a couple of lemons that you keep stashed in a fruit bowl so that you can add lemon juice to something that you're consuming if you've forgotten to include it as part of the meal. But otherwise, making sure you've got those vitamin C rich foods as part of your normal grocery shop, mixing it up - having different colours, obviously, just trying to include those options. 

Rebecca Hall  22:17
Also thinking about, if you are taking supplementation, can you prioritise it immediately post-training and try and keep it somewhat separate? And I’d imagine triathletes, like everyone, are very keen on coffee. So if you can, if you're a milky coffee person, but even if you're a black coffee person or a black tea person, trying to separate your caffeine and your dairy consumption from your iron supplementation, or your iron rich foods, by about an hour.

Taryn Richardson  22:43
That's great advice for all of the caffeine loving triathletes.

Rebecca Hall  22:47
Yes, they’ll be out cursing my name, no doubt! But just separating it by an hour would be a great way to try and increase the chances that you get as much iron out of your meal as possible.

Taryn Richardson  23:57
They might argue with you that caffeine helps with glycogen uptake. So we might need to think of another way to get around that one for them.

Rebecca Hall  23:06
We can work on that, we'll workshop later.

Taryn Richardson  23:10
Well, thank you so much for joining me, Becky. That's some really good practical tips for people and an introduction to what iron is and why it's so important for them. I find a lot of athletes have no idea that they're even iron-deficient until their iron is through the floor. And no idea also how to eat to manage iron because it's so complicated - massive bioavailability and blockers and enhancers and it's so confusing. But some of those things that you said today are really practical, easy things that someone can walk away with and go and do tomorrow.

Rebecca Hall  23:38
Well hopefully they can even do it today if they've listened. So yeah, good luck to everyone. And yet it's not nearly as hard as it needs to be.

Taryn Richardson  23:42
Thank you, Becky.

Rebecca Hall  23:43
You're welcome. Bye.


Taryn Richardson  26:56
Thanks for joining me for this episode of the Triathlon Nutrition Academy podcast. I would love to hear from you. If you have any questions or want to share with me what you've learned. Email me at [email protected]. You could also spread the word by leaving me a review and taking a screenshot of you listening to the show. Don't forget to tag me on social media at @dietitian.approved so I can give you a shout out too. If you want to learn more about what we do, head to dietitianapproved.com. And if you want to learn more about the Triathlon Nutrition Academy program, head to dietitianapproved.com/academy. Thanks for joining me and I look forward to helping you smash it in the fourth leg - nutrition!

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