Intense physical exertion increases the body’s need for iron, and repeated sessions that deplete the body may lead to iron deficiency anaemia with inadequate iron intake or poor absorption. As previously mentioned, iron deficiency may contribute to exhaustion and will likely have an adverse effect on training and competition.

Iron is an essential mineral that plays a vital role in metabolism and the transportation of oxygen through your body. Up to 65% of the body’s iron is found in haemoglobin. Haemoglobin is the substance found in red blood cells that delivers oxygen from your lungs to your body tissues via your bloodstream. This means that low haemoglobin levels lead to decreased oxygen delivery to the body’s tissues, working muscles and organs.

Iron is also essential for the formation of myoglobin in muscle cells, a protein that carries and stores oxygen in muscle tissue. As oxygen is needed for aerobic metabolism, it’s easy to understand how low myoglobin (oxygen transportation around the muscles) impairs your aerobic function and ultimately, physical performance. It is also essential for brain health, physical growth and the synthesis of several hormones in your body. If you aren’t sure of the common signs of iron deficiency, you may like to read our previous blog here.

Put simply, if you are suffering from anaemia or are iron deficient your muscles will receive less oxygen and produce more lactic acid during training sessions, and your health and wellbeing will be severely compromised and could lead to serious health issues.

Energy production takes place in the mitochondria as part of the electron transport chain. In this process, a charged gradient is created across the membrane, which in turn drives the synthesis of energy as adenosine triphosphate (ATP).  Both haem animal and plant-based forms of iron are important for the protein complexes within the electron transport chain.

Iron is found in mitochondria within skeletal muscles storing 10–15% of the body’s iron. Iron is particularly concentrated in type-1 slow-twitch muscle fibres. These fibres have high mitochondria concentrations, slow contraction rates and a reliance on aerobic metabolism and oxidative phosphorylation.

Endurance athletes typically have more slow twitch muscle fibres than type-2 fibres.

Vegetarian or plant-based athletes are at a much higher risk of iron deficiency and may need significantly more iron in their diet,  due to the reduced bioavailability of iron from plant-based foods. Knowledge of sources of iron-rich foods and beneficial combinations of foods can be helpful. For example: pairing plant-based iron-rich foods with a source of vitamin C can increase iron absorption.

It is important to remember that your iron deficiency may have nothing to do with your iron intake and other physiological and environmental circumstances may be contributing to iron deficiency.

Tools such as our  Anaemia Quiz may help to identify if you are at risk of iron deficiency or anaemia.

Want to know more? Contact the Athlete Sanctuary and learn how we can help.

About the Author: Kate Smyth is a Sports naturopath, nutritionist and female centric running coach. She is the founder of the Athlete Sanctuary- a holistic healthcare clinic for athletes of all levels and sporting codes. Kate has a thirst for knowledge with two bachelor’s and a master’s degree under her belt. She has been involved in sports for many decades and competed for Australia in the Commonwealth Games and Olympic Games marathons with a personal best time of 2 hours 28 minutes. For more information visit https://athletesanctuary.com.au/kate-smyth

References

Alaunyte I, Stojceska V, Plunkett A. (2015). Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. J Int Soc Sports Nutr. 12. doi:10.1186/s12970-015-0099-2

Halas M. (2009): Special Considerations for Vegans and Vegetarians. The Plant-Based Boost Nutrition Solutions for Athletes and Exercise Enthusiasts. Middletown, DE: Super Kids Nutrition Incorporated.

Semenova, E. A., Miyamoto-Mikami, E., Akimov, E. B., Al-Khelaifi, F., Murakami, H., Zempo, H., ... & Ahmetov, I. I. (2020). The association of HFE gene H63D polymorphism with endurance athlete status and aerobic capacity: novel findings and a meta-analysis. European Journal of Applied Physiology, 120(3), 665-673.

Stugiewicz, M., Tkaczyszyn, M., Kasztura, M., Banasiak, W., Ponikowski, P., & Jankowska, E. A. (2016). The influence of iron deficiency on the functioning of skeletal muscles: experimental evidence and clinical implications. European Journal of heart failure, 18(7), 762-773. 

Have you ever heard of hepcidin? It’s worth understanding mainly if you are a female athlete or someone who suffers from iron deficiency anaemia.

Iron is an essential element for many biological processes. Too little iron can have many detrimental effects on your health and sports performance. We have previously discussed the impact iron deficiency and anaemia has on thyroid health and poor immunity. Excess iron can be toxic, so regulating iron levels are vital to a healthy, balanced body.

Hepcidin is an iron-regulating peptide hormone that’s produced in your liver. It works to control the delivery of iron to your blood from food through the lining of the intestines. It is the master regulator in iron metabolism and the balance between iron storage and the absorption better known as iron homeostasis. Hepcidin also tightly influences red blood cell production.

When hepcidin levels are unusually high, it reduces intestinal iron absorption and red blood cell production. Low hepcidin levels stimulate iron absorption, and iron supply to bone marrow and promote hemoglobin and red blood cell production. Iron deficiency is common among female athletes, and is much higher than their male counterparts. It is often cited as being a result of the menstrual cycle during premenopausal years. Depleted iron stores can have many adverse effects, including poor performance, low energy levels, and general well-being.

Some research has shown that active females with compromised iron possess an inherent protective mechanism once iron deficient. This adaptation allows the body to adjust to a reduced iron supply. It is proposed iron depletion may be a combination of exercise-induced losses and hepcidin accumulation.

Running is known to acutely increase hepcidin levels (peaking three hours post-exercise), therefore reducing iron absorption and recycling.

Timing iron supplementation to correlate with low hepcidin levels may enhance absorption and positively impact iron levels in the blood. In practical terms, if you exercise in the morning, you might consider taking your iron supplement straight after you exercise, before hepcidin rises.

Hundreds of athletes have used our handy anaemia quiz to help determine the likely risk of having low iron or anaemia. we encourage you to use this free tool if you have a history of iron deficiency or you are unsure if your iron stores may be declining.

Want to know more? Contact the Athlete Sanctuary to learn how we can support you further. Book an appointment here.

About the Author: Kate Smyth is a Sports naturopath, nutritionist and female-centric running coach. She is the founder of the Athlete Sanctuary- a holistic healthcare clinic for athletes of all levels and sporting codes. Kate has a thirst for knowledge with two bachelor’s and a master’s degree under her belt. She has been involved in sports for many decades and competed for Australia in the Commonwealth Games and Olympic Games marathons with a personal best time of 2 hours 28 minutes. For more information visit https://athletesanctuary.com.au/kate-smyth

References

Ganz, T. (2016). Hepcidin. Rinsho Ketsueki, 57(10), 1913-1917. DOI: 10.11406/rinketsu.57.1913.

Sim, M., Dawson, B., Landers, G., Trinder, D., & Peeling, P. (2014). Iron regulation in athletes: exploring the menstrual cycle and effects of different exercise modalities on hepcidin production. International journal of sport nutrition and exercise metabolism, 24(2), 177-187.https://pubmed.ncbi.nlm.nih.gov/24225901/

Alfaro-Magallanes, V. M., Benito, P. J., Rael, B., Barba-Moreno, L., Romero-Parra, N., Cupeiro, R. FEMME Study Group. (2020). Menopause Delays the Typical Recovery of Pre-Exercise Hepcidin Levels after High-Intensity Interval Running Exercise in Endurance-Trained Women. Nutrients, 12(12), 3866. https://pubmed.ncbi.nlm.nih.gov/33348847/

Nirengi, S., Taniguchi, H., Ishibashi, A., Fujibayashi, M., Akiyama, N., Kotani, K., & Sakane, N. (2021). Comparisons between serum levels of hepcidin and leptin in male college-level endurance runners and sprinters. Frontiers in Nutrition, 8. https://pubmed.ncbi.nlm.nih.gov/34136516/

Pagani, A., Nai, A., Silvestri, L., & Camaschella, C. (2019). Hepcidin and anemia: a tight relationship. Frontiers in physiology, 1294.  https://www.frontiersin.org/articles/10.3389/fphys.2019.01294/full

Sim, M., Dawson, B., Landers, G., Trinder, D., & Peeling, P. (2014). Iron regulation in athletes: exploring the menstrual cycle and effects of different exercise modalities on hepcidin production. International journal of sports nutrition and exercise metabolism, 24(2), 177-187.  https://pubmed.ncbi.nlm.nih.gov/24225901/[/vc_column_text][/vc_column][/vc_row]

Iron plays a crucial physiological role in your body. But despite its importance, iron deficiency anaemia is still a common problem among female athletes. Iron deficiency can have major adverse effects on your well-being and your athletic capacity.

It’s not uncommon for iron deficiency anaemia to be quite mild and go unnoticed. But women – and especially active, athletic women – are very prone to this condition. If gone untreated, the anaemia will worsen, and the signs and symptoms will intensify.

Without enough iron, your body can’t produce enough hemoglobin – the substance in red blood cells that enables them to carry oxygen – and as a result iron deficiency anaemia can leave you short of breath, headachy, tired, and unable to complete a training session or event with your usual enthusiasm. Iron deficiency is missed in 47-82% of females and 95-100% of male adolescents and young adult patients.

10 signs of iron deficiency  

*Fatigue that starts even after a good night’s sleep

*Restless legs

*Nausea

*Bruising

*Pale or itchy skin

*Hair loss

*Shortness of breath

*Poor concentration and decision-making, “foggy brain”

*Rapid heartbeat or “fluttering feeling”

*Headache, dizziness or light-headedness

Keep in mind this is just a small number of the  75 known symptoms of iron deficiency. Unusual cravings for non-nutritive substances, such as ice and dirt

CAUSES OF IRON DEFICIENCY

Low or little dietary intake of iron-rich foods is often blamed as the key factor contributing to iron deficiency. With plant-based eating increasing in popularity amongst the athlete community, this is a key factor for many athletes. Lack of awareness of how to consume foods that enhance iron absorption or knowledge on sources of plant-based iron-rich foods can render an athlete with symptoms in a matter of months.  Poor intake however is not the only cause of iron deficiency anaemia.

*Blood loss. Blood contains iron within red blood cells. If you lose blood, you lose some iron. Women with heavy periods are at risk of iron deficiency anaemia because they lose blood during menstruation. Athletes who are frequent blood donors are at increased risk for iron deficiency.¹ Athletes who regularly use nonsteroidal anti-inflammatories are likely to have increased gastrointestinal blood losses increasing their risk of iron deficiency³.

*An inability to absorb iron. Dietary iron is absorbed into the bloodstream through the small intestine. An intestinal disorder, such as celiac disease, stomach ulcers, ulcerative colitis or Crohn’s disease, which affects the intestine's ability to absorb nutrients from digested food, can lead to iron-deficiency anaemia. If part of the small intestine has been bypassed or removed surgically, the ability to absorb iron and other nutrients will be reduced. Inflammation in the digestive tract is aligned with symptoms such as bloating, gas, diarrhoea or constipation, food intolerances, or loud gurgling, and may signal the integrity of the gut lining may be compromised. Without good integrity, absorption of nutrients is also reduced.

*Low stomach acid. Adequate stomach acid (hydrochloric acid- HCL) is required to break down minerals such as iron and extract them from the food we eat. Low stomach acid is a common issue following times of prolonged physical or emotional stress and can be found alongside iron deficiency.

*Iron stealers. Bacteria overgrowth, Helicobacter pylori, and parasites within the digestive tract can impact the way iron is absorbed and may contribute to blood loss, therefore, contributing to iron deficiency over time.

*Post natal- Without iron supplementation, iron deficiency anaemia occurs in many pregnant women due to the iron requirements of the mother and baby. Post-natal iron deficiency can occur as many women are naturally preoccupied with their new arrival and forget to have adequate medical checkups for themselves. Fatigue is often experienced by mother’s and therefore iron deficiency can go undetected for many months. This depletes not only the mother but also the baby’s supply of iron who depends on the mother for iron for the first 6 months of life until solids are introduced.

Hundreds of athletes have used our handy anaemia quiz to help determine the likely risk of having low iron or anaemia. Find out if you are getting low on iron here.

Want to know more? Contact the Athlete Sanctuary to learn how we can support you further.

About the Author: Kate Smyth is a Sports naturopath, nutritionist and female-centric running coach. She is the founder of the Athlete Sanctuary- a holistic healthcare clinic for athletes of all levels and sporting codes. Kate has a thirst for knowledge with two bachelor’s and a master’s degree under her belt. She has been involved in sports for many decades and competed for Australia in the Commonwealth Games and Olympic Games marathons with a personal best time of 2 hours 28 minutes. For more information visit https://athletesanctuary.com.au/kate-smyth

References

1. Choe, Y. H., Kwon, Y. S., Jung, M. K., Kang, S. K., Hwang, T. S., & Hong, Y. C. (2001). Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes. The journal of Pediatrics, 139(1), 100-104.
2. Eiduson, R., Heeney, M. M., Kao, P.-C., London, W. B., Fleming, M. D., & Shrier, L. A. (2022). Prevalence and Predictors of Iron Deficiency in Adolescent and Young Adult Outpatients: Implications for Screening. Clinical Pediatrics, 61(1), 66–75. https://doi.org/10.1177/00099228211059647
3. Safarova, K. N., Dorogoykina, K. D., & Rebrov, A. P. (2019). Is anemia a clinical marker of NSAID-induced upper gastrointestinal lesions in patients with spondyloarthritis?. Almanac of Clinical Medicine, 47(5), 410-418. https://doi.org/10.18786/2072-0505-2019-47-037
4. Hinton P. S. (2014). Iron and the endurance athlete. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolism, 39(9), 1012–1018. https://doi.org/10.1139/apnm-2014-0147
5. Mayo Clinic (2022). Iron Deficiency anemia. https://www.mayoclinic.org
6. Sim, M., Dawson, B., Landers, G., Trinder, D., & Peeling, P. (2014). Iron regulation in athletes: exploring the menstrual cycle and effects of different exercise modalities on hepcidin production. International journal of sports nutrition and exercise metabolism, 24(2), 177–187. https://doi.org/10.1123/ijsnem.2013-0067

Iron deficiency is one of the most common issues athletes face.  Iron and thyroid health go hand in hand and the effects of exercise on the thyroid gland and hormones are not well understood.

Iron and thyroid function 
Undiagnosed iron deficiency presents an increased risk of impaired thyroid function. Active women have high-energy lives, managing work, family and training, and many will accept low energy and brain fog as simply a result of being overworked or as an inevitable part of hormonal changes.

However, low thyroid function, iron deficiency, overtraining and hormonal changes also present with many of the same symptoms.

Signs that your thyroid function may be underactive (hypothyroid) include fatigue, unexplained weight gain, headaches, low blood pressure, dry skin, constipation and cold intolerance. These early signs of cellular hypothyroidism can appear when blood pathology remains within standard ranges.

As with most chronic issues, there are multiple factors that may contribute to dysfunction.

The Link between Exercise and Thyroid Function

In athletes, endurance and high-volume training promotes thyroid function. During exercise, your hypothalamus stimulates the pituitary gland to secrete thyroid-stimulating hormone (TSH), which in turn signals your thyroid to synthesise and release the thyroid storage hormone T4 and active thyroid hormone T3.

These hormones influence your body’s metabolism and allow it to increase exercise intensity. Over time, this repeated, high demand of your thyroid during prolonged intense exercise may impact your thyroid function, causing it to slow down and consequently lose the ability to produce sufficient hormones.

Iron and Thyroid Function

Normal thyroid function is dependent on several nutrients to regulate the synthesis of thyroid hormones. Iodine, iron, tyrosine, selenium, and zinc are needed to facilitate the conversion of T4 to T3 . A deficiency of any one of these nutrients would result in reduced T3 production, causing you to experience hypothyroid symptoms. Vitamins A and D also play important roles in cell receptor behaviour to regulate thyroid hormone metabolism.

While iodine is the key mineral for healthy thyroid function (read more…here)  it is not uncommon to find iron deficiency in hypothyroidism. Although widely recognised for its influence on red blood cell production, iron is also an important component of thyroid peroxidase, an enzyme essential for thyroid hormone biosynthesis.

Iron deficiency interferes with the normal functioning of the thyroid, contributing significantly to fatigue, exercise intolerance and lightheadedness.

Increased menstrual bleeding can lead to iron deficiency. Many of us dismiss low energy as a symptom of a busy, active lifestyle and so iron deficiency frequently goes undiagnosed in perimenopausal women.  For athletes, iron plays a critical role in exercise performance as outlined in our blog “Increase your iron absorption and rebound from anaemia” here

The most common causes of iron deficiency include inadequate dietary iron intake, inflammation, poor iron absorption in the gut, parasites, iron loss through sweat, urination and faeces, blood loss through menstruation. Pregnancy, breastfeeding or high-volume exercise will also significantly increase iron demands. Take our free anaemia quiz to see if you may be iron deficient here

Thyroid Function and Sex Hormones in Women

Your thyroid function is sensitive to fluctuations in sex hormone levels, particularly oestrogen. Oestrogen stimulates the production of the thyroid hormone precursor, thyroglobulin, and increases the protein that carries thyroid hormones in your blood.

As oestrogen changes (such as during peri-menopause) so too does thyroid hormones, which play an important role in metabolism, muscle strength, energy production and expenditure, heart function, and temperature regulation.

As oestrogen levels rise and fall later in life, menstruation may become irregular and heavier. Peri-menopausal women may experience symptoms for over ten years as described in our blog on “Natural solutions for menopause” here .

During peri-menopause declining oestrogen may impact thyroid function and can lead to inadequate production and circulation of thyroid hormones.

Exercise During Hormonal Changes

Despite common misconceptions, women can train and perform well throughout peri-menopause, and beyond, if they listen to their bodies and be mindful of maintaining adequate dietary intake of key nutrients. It is important to recognise that both iron deficiency, thyroid function and hormonal changes can impact your ability to exercise.

Years of consistent exercise accumulate like pages in a book. As a mature you know your body very well. The pathway to success utilises your book of wisdom and skills. Mature athletes can benefit from greater recovery, individualized strength and conditioning and modified programs. Focussing on the balance between training intensity and volume will help you to achieve your desired goals.

If you suspect your symptoms are impacting on your quality of life and sport, it’s time to seek support to help you navigate the journey.

Blood serum pathology and functional tissue mineral testing can be a good starting point due to the critical role nutrients play in hormonal and thyroid function.

With the right self-care and a holistic approach to health, you can continue to achieve your life goals and physical challenges irrespective of hormonal changes.

About the Author: Kate Smyth is a Sports naturopath, nutritionist and female-centric running coach. She is the founder of the Athlete Sanctuary- a holistic healthcare clinic for athletes of all levels and sporting codes. Kate has a thirst for knowledge with two bachelor’s and a master’s degree under her belt. She has been involved in sports for many decades and competed for Australia in the Commonwealth Games and Olympic Games marathons with a personal best time of 2 hours 28 minutes. For more information visit https://athletesanctuary.com.au/kate-smyth

References

1. Kawicka, A., & Regulska-Ilow, B. (2015). Metabolic disorders and nutritional status in autoimmune thyroid diseases. Postepy Higieny i Medycyny Doswiadczalnej, 69, 80–90.
2. Luksch, J. R., & Collins, P. B. (2018). Thyroid Disorders in Athletes. Current Sports Medicine Reports, 17(2), 59–64.
3. Santin, A. P., & Furlanetto, T. W. (2011). Role of estrogen in thyroid function and growth regulation. Journal of Thyroid Research, 2011.
4. Soliman, A. T., De Sanctis, V., Yassin, M., Wagdy, M., & Soliman, N. (2017). Chronic anemia and thyroid function. Acta Biomedica, 88(1), 119–127.
5. Wouthuyzen-Bakker, M., & Van Assen, S. (2015). Exercise-induced anaemia: A forgotten cause of iron deficiency anaemia in young adults. British Journal of General Practice, 65(634), 268–269.

Mineral testing provides a wider perspective on an individual’s overall health status than just urine, blood or stool pathology testing alone although it is always useful to use both tests in conjunction with each other. Mineral testing can be used as an early detector of subclinical issues and provide useful guidelines in terms of how to best support the body when annoying symptoms such as fatigue, insomnia and digestion issues persist.

In clinical practice, test results are always accompanied by a thorough assessment of your overall health and nutritional intake to provide meaningful context to data and to give you a clear understanding of where and how deficits may be occurring.

A mineral analysis may provide insight into your current health status, identify potential areas of concern and provide suggestions around dietary and supplemental measures that may improve your health now and prevent issues in the future.

Mineral testing for athletes- useful insights

Mineral testing provides a snapshot of how the body is utilizing the nutrients obtained from your food and provides an analysis of 13 key minerals. Trends in nutrient deficiencies or excessive mineral levels may indicate poor activation and non-beneficial storage of nutrients.

To demonstrate this point, let’s take a look at calcium. Calcium will be maintained within a very narrow range in blood serum due to its life-supporting roles in managing heart rate, nerves, and muscle function. However, in a mineral analysis high or levels of calcium may be observed.  Low levels of calcium may indicate poor absorption, inadequate intake or other nutrient issues such as low vitamin D, while high levels may be suggestive of low vitamin B6 and poor calcium utilisation in the body.

High calcium levels may also contribute to underactive thyroid issues with symptoms such as weight gain, fatigue, low blood pressure and poor mood. Early detection of calcium issues is vital for the prevention of bone issues such as osteopenia, fractures, bone spurs, kidney stones and thyroid issues.

Mineral testing for athletes provides an analysis of how the body is utilizing 13 key nutrients obtained from the athlete's diet. Longer-term patterns in nutrient deficiencies or excesses may indicate poor activation and non-beneficial storage of nutrients.

To demonstrate this point, let’s take a look at calcium. Calcium will be maintained within a very narrow range in blood serum due to its life supporting roles in managing heart rate, nerves, and muscle function. However, in a mineral analysis high or levels of calcium may be observed.  Low levels of calcium in mineral testing for athletes, may indicate poor absorption, inadequate intake or other nutrient issues such as low vitamin D. High levels in mineral testing for athletes, may be suggestive of low vitamin B6 and poor calcium utilisation in the body.

High calcium levels may also contribute to underactive thyroid issues with symptoms such as weight gain, fatigue, low blood pressure and poor mood. Early detection of calcium issues is vital for the prevention of bone issues such as osteopenia, fractures, bone spurs, kidney stones and thyroid issues.

Significance of mineral testing for athletes

A clinical understanding of how an individual metabolises and utilises nutrients can be obtained through various mineral ratios included in a mineral test.  Just some of the ratios contained in the mineral analysis report are outlined below:

Immunity: Low zinc in relation to high copper levels may indicate a susceptibility to viral infections such as colds, cold sore outbreaks or poor wound healing. Zinc is critical to immune cell function and digestion and hydrochloric acid. Reduced digestive function and symptoms such as bloating, diarrhoea, malabsorption and low nutrient levels may also be observed in patients with low zinc.

Iron deficiency and anaemia: As discussed previously in relation to immunity, ceruloplasmin is a protein carrier shared by zinc, copper and iron. If zinc, copper or iron are too high, they may inhibit the absorption of the other minerals. For example -high levels of copper may be observed in women taking the oral contraceptive pill or through drinking water carried in copper pipes.  High copper levels may contribute to iron deficiency anaemia and present as shortness of breath, lethargy, dizziness and exercise fatigue.

Poor liver detoxification: Molybdenum is a key nutrient required for liver detoxification and is frequently low on test results due to reduced intake of foods rich in molybdenum such as legumes. When molybdenum is low in relation to sulfur an individual may experience sluggishness, fatigue, skin issues, and poor recovery related to reduced sulfation detoxification pathways in the liver.

Blood sugar control issues: Manganese and chromium are key nutrients required for blood sugar control. When manganese is low in relation to chromium an individual may experience energy dips, especially after meals, sugar cravings and dizziness or sweating related to poor blood sugar control and fluctuating insulin levels.

Hormone issues: Minerals play a key role in hormone modulation. When iron is low in relation to copper, individuals may complain of fatigue, poor recovery, weakness, loss of libido, irregular periods and hot flushes due to a pattern of low progesterone or testosterone.

Adrenal gland insufficiency: During times of stress, the adrenal gland utilises larger amounts of sodium and magnesium. When sodium levels are low in comparison to magnesium the adrenal gland may be underperforming as it is highly sodium dependent to produce key hormones such as cortisol.

General muscle tightness: Calcium and magnesium are required for bone health and muscle and nerve function. Stiff muscles, bladder issues and immobile joints may present when there is an issue between the ratio of calcium and magnesium in the body.

HEAVY METAL BURDEN
This form of testing may also identify heavy metal burden on the body. Despite a clean lifestyle, individuals can present with unfavourable levels of mercury, arsenic, lead, tin or aluminium largely due to living in a modern environment where exposure to heavy metals occurs on a regular basis.

Contrary to popular belief, heavy metal accumulation does not necessarily occur from occupational exposure. Frequent exposure arises from pesticides; additives and the tinning of foods; dental fillings; drinking water; products and materials used in homes and offices; personal care products and cosmetics.

Heavy metals are neurotoxins and may over time contribute to a plethora of health issues such as thyroid, reproductive and mental health issues, and cancers. Heavy metals displace other key minerals such as zinc, selenium and iron. The presence of these metals may also be indicative of other functional issues such as reduced liver detoxification pathways.

Practicalities of mineral testing for athletes

Mineral testing looks at long-term trends (over 2-3 months) and can be very useful when symptoms or health issues are ongoing and underlying contributing factors are yet to be identified.  Athletes also find mineral balance results useful before they launch a new training campaign as a measure of nutritional status and as a preventative measure against deficiencies that may inhibit performance.

Mineral testing does not require a blood draw and can be conducted in the privacy of your own home.  Test results generally take 2 weeks and are reviewed during an extended consultation.

For further information or to order a test kit email contact us or book in for your initial consultation.

Thyroid hormones perform many key functions in the human body including regulation of body temperature, metabolism and play an important role in how an athlete creates and uses energy. Thyroid hormones bind to receptors on each cell’s membrane surface and inside the cell at the mitochondria where energy is made. Binding activates the cell’s energy and metabolic functions.

Iodine is a key trace mineral stored primarily in the thyroid gland. The thyroid gland produces the key thyroid hormones thyroxine (T4) and triiodothyronine (T3), using iodine and other key nutrients such as selenium and tyrosine.  To further convert thyroid hormones into activated forms the body can use, sufficient levels of magnesium, iron, selenium, vitamin C and zinc are also required.

Key hallmarks of iodine deficiency and low thyroid function in athletes include:

• Fatigue and low stamina can really cause havoc to an athlete’s training and racing season
• Lethargy, muscle aches, cramps, pains and weakness
• Low basal body temperature (temperature first thing in the morning)
• Intolerance to cold weather
• Cold hands and feet
• Slow brain function, poor memory and “foggy” brain
• Constipation
• Joint pain
• Thin, brittle hair or hair loss
• Dry flaky skin
• Menstrual disorders and fertility problems
• Weight gain and slower metabolic rate

Iodine is primarily lost through sweat, although some are also excreted in the urine.  Some studies suggest athletes may lose more iodine through sweat in an hour of vigorous exercise than through their entire daily urine output.  High levels of sweating during exercise can deplete iodine levels and result in dehydration and poor performance.

The recommended iodine intake is 150ug/ day but some studies show on average athletes may lose nearly 50% of this requirement in sweat alone. Athletes living in more humid conditions (even without exercise) can lose a greater amount of sweat than those living in cooler environments.

Athletes performing at high intensity for prolonged periods of time, particularly in a humid environment, have a significantly increased risk of becoming iodine deficient if they don’t pay special attention to replacing this important nutrient.

What else can impact iodine and thyroid function?

It is important to keep in mind there are lots of things that impact the thyroid gland.

Chronic physical or emotional stress and high cortisol will result in elevations of another thyroid hormone called reverse T3 (rT3). Pesky rT3 inhibits our active thyroid hormone T3.

Heavy metals and chemicals, a low carbohydrate diet and fasting and selenium deficiency can also reduce T3 levels.  There are many chemicals and metals in our environment known as “endocrine disruptors” that inhibit healthy thyroid function. Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are common in our environment containments (in soil and food grown in that soil including meat, electronics, electrical cables, paints, plastics, furniture ) which can disrupt thyroid hormone signalling at the receptor level.

Perchlorate found in food and water inhibits the thyroid’s ability to absorb iodine from the bloodstream while long-term consumption of fluoridated drinking water is associated with hypothyroidism (low thyroid function).

Dioxins, BPA (found in cling wrap, drinking bottles and plastics) or bisphenols in tinned foods and plastic containers and plastic wraps, are also endocrine disruptors.

Non-stick cookware, fragrances, detergents, cosmetics and skincare, foods exposed to pesticides and herbicides, flame retardant material, new carpets, furniture and clothing may also be sources of endocrine disruptors.

When a female athlete has excess oestrogen, it may reduce the efficiency of thyroid hormone by 25%. Female athletes with high testosterone levels or insulin resistance may also have reduced thyroid efficiency due to a reduction in the globulin that carries thyroid hormone around the body (thyroid binding globulin) which means not enough thyroid hormone can circulate. But the hormone dance doesn’t stop there.

Low thyroid function due to low iodine or other nutrients can also cause receptor sensitivity issues with other female hormones such as progesterone causing PMS symptoms, irregular periods and fertility issues.

Cortisol up-regulates estrogen and high oestrogen also up-regulates cortisol which increases the binding of T4 up to 3 times, resulting in lower thyroid hormone activity, lowered metabolism and weight gain.

As thyroid hormones influence the tight junctions in the stomach and small intestine, athletes with low iodine and thyroid can also suffer from digestive complaints such as gas, bloating, diarrhoea or constipation and digestive infections.

Approximately 20% of our thyroid hormone T4 is converted to T3 in the gut by bacteria. So if digestion is disrupted and inflammation exists, the conversion will be impacted. Thyroid hormones also influence the tight junctions in the stomach and intestine that prevent large undigested molecules from passing into our bloodstream. Hence why thyroid abnormalities are also associated with leaky gut, food intolerances, constipation, reflux, heartburn, and dysbiosis (gut microbiome imbalance).

Thyroid hormones also influence the foundation of our immune system in the stomach called Gut Associated Lymphoid Tissue (GALT). GALT is made up of several types of lymphoid tissue that store immune cells, such as T and B lymphocytes. The majority of infectious agents invading the human body gain access through the gut and GALT protects us against these pathogens.  Therefore, an athlete can be more susceptible to infections if thyroid hormones are low or iodine deficiency exists. n

Other nutrients have an impact on iodine and thyroid function. Many athletes suffer from anaemia or low iron and believe their fatigue and poor performance may just be iron related. The situation is a double-edged sword as iron deficiency impairs thyroid hormone synthesis and low thyroid function impairs gastric secretions which reduce iron absorption from food.

Another tricky synergy exists between zinc, copper and thyroid function. Zinc is required for T4 and T3 production and therefore zinc deficiency may lead to low gastric secretions and low iron. Zinc and copper also antagonise each other so low zinc may lead to high copper.  Excess copper slows thyroid function and depletes zinc.

Iodine concentration in foods is variable depending on soil concentrations and the amount of fertilizer used with farming methods. Therefore, our food iodine content also varies greatly in grains, meats and vegetables. Although the daily recommended iodine intake is 150ug, it can still be tricky even when eating iodine food sources due to such variability.

Metabolic acidosis is a condition when the body’s pH is too acidic (pH of 7.35 or lower). This may occur in athletes from prolonged exercise at high intensity leading to lactic acid build-up. Chronic metabolic acidosis may decrease T4 and T3 and increase TSH concentrations and may lead to subclinical hypothyroid states.

1. Tracking athletes’ basal (morning) body temperature can assist with identifying issues with thyroid function. Anything less than 36.4c suggests your thyroid may need some attention.
2. Athletes should not rely on blood tests to confirm thyroid function status. Under activity of the thyroid gland results in low basal temperatures and symptoms of low thyroid function are not detectable by the standard laboratory tests-thyroid stimulating hormone (TSH), T4 and T3.
3. Athletes should consume sufficient sources of iodine on a regular basis. Good food sources include seafood (wild sea fish contain more iodine than freshwater fish), kelp and other seaweeds (wakame, Kombu, Nori), kelp noodles, Sushi are a rich source of iodine. Other reasonable sources include milk and yogurt, navy beans, eggs, cranberries, strawberries and some meats.
4. Since 2009 all packaged bread has added iodine in Australia although freshly baked bread may not disclose the amount added. Iodized salt is also available but keep in mind too much salt is not great for blood pressure and even sea salt and Himalayan salt contains 90% sodium chloride which is not desirable as chloride inhibits iodine absorption.
5. Be mindful of high intake of goitrogenic vegetables. The cabbage family including cabbage, kale, broccoli, cauliflower, Brussels sprouts, radishes, turnips, watercress, spinach contain isothiocyanates (goitrogens) which may block the uptake and utilisation of iodine in the thyroid gland. Cooking these vegetables reduces the goitrogens and the likelihood of their impact.
6. Although controversial, some evidence suggests soy supplements such as soy protein powders should be avoided if you have been diagnosed with low thyroid function as they may also reduce the genetic expression of the enzymes needed to produce thyroid hormones.
7. Get your vitamin D levels checked. Vitamin D deficiency is common in Australia and in athletes with low body fat this issue can be even more prevalent as Vitamin D is stored in fat cells. Vitamin D is associated with hypothyroidism and thyroid autoimmune conditions while studies show serum vitamin D > 125 is associated with a 30% reduced risk of hypothyroidism.
8. Get your hormones, cortisol, iron, zinc, copper and iodine levels checked.
9. Improve your gastric acid secretions by consuming bitter foods (endive, rocket, radicchio, chicory, dark chocolate) on a regular basis or sip lemon in water or apple cider vinegar before meals.
10. Reduce your exposure to endocrine disruptors by drinking filtered water, installing filters on shower heads, choosing natural water sources to swim in rather than chlorinated pools, eating pesticide-free or ideally organic foods, choosing organic personal care products, cosmetics and detergents, avoiding storage of food in plastics and instead use wax wraps and choose low emitting products when renovating or building your home.

If you suspect you may be suffering from iodine deficiency or reduced thyroid function, consider making an appointment with the Athlete Sanctuary to help navigate your recovery process.

About the Author: Kate Smyth is a Sports naturopath, nutritionist and female-centric running coach. She is the founder of the Athlete Sanctuary- a holistic healthcare clinic for athletes of all levels and sporting codes. Kate has a thirst for knowledge with two bachelor’s and a master’s degree under her belt. She has been involved in sports for many decades and competed for Australia in the Commonwealth Games and Olympic Games marathons with a personal best time of 2 hours 28 minutes. For more information visit https://athletesanctuary.com.au/kate-smyth

Iron is also needed for protein metabolism, collagen and antioxidant synthesis, as a co-factor for key enzymes involved in energy production, muscles, DNA and hormone synthesis; and immune function. Iron plays a key role in forming hemoglobin in red blood cells. Haemoglobin is necessary for the transportation of oxygen around the body and is critical to athletic performance.

If left untreated, iron deficiency and anaemia may contribute to decreased endurance; reduced training capacity and recovery lead to more frequent colds and other infections.

Why athletes have an increased risk of iron deficiency or anaemia

• Greater iron utilisation and requirements of iron
• Inflammation reduces the body's ability to store iron,
• Gastrointestinal tract stress limiting the absorption of iron through nutrition and blood loss,
• Loss of iron through sweat 
• Haemolytic breakdown of red blood cells through footstrike
• Blood loss may also occur through urine 
• Insufficient intake of iron-rich foods  and more plant-based foods
• Heavy periods in female athletes

In the general population, anaemia most commonly results from nutrient deficiencies due to low intake of iron-rich foods and blood loss, such as with heavy periods, haemorrhoids or gastric ulcers. Surgery, eating disorders, exposure to viruses (e.g. Malaria), toxins (e.g. lead) or renal disease, and some drugs reduce iron absorption. Low stomach acid, diarrhoea, Coeliac’s and Crohn’s disease and gastric bypass also decrease iron absorption. Increased requirements, such as in pregnancy, can also lead to deficiencies.

Iron is found in plants and animal meats
It is important to remember there are two different forms of dietary iron.

Heme iron is found in animal meats such as liver, lamb, beef and kangaroo.
Non-heme iron is derived from plant sources such as legumes, dried fruits, nuts and leafy green vegetables, tofu and eggs.

As the body must change the structure of the non-heme iron before it can be absorbed, heme iron from animal products is more bioavailable for the body. This doesn’t mean a vegetarian will always be low in iron, it just means they need to be smart about where they get their iron, and ensuring they include high amounts of other nutrients that aid absorption of iron.

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TOP 10 TIPS - To increase your iron absorption

*Consume foods high in vitamin C such as capsicum, berries, citrus and guava and malic acid-rich foods such as watermelon, berries, kiwi, apricots and mango in the same meal to enhance non-heme iron absorption. Don't forget nature's wonders, such as parsley and beetroot, which are also great blood builders.

*Eat fresh wholefoods. Consume 2 serves of fruits mentioned above per day plus 5-7 serves of vegetables and 2-3 serves of wholegrains per day. These foods provide nutrients that aid iron metabolism such as copper, vitamin A, vitamin B2, B12, folic acid, molybdenum, selenium and amino acids.

*Eat red meat, fish or chicken with vegetables. Consuming meat at the same time as plant-based sources of iron can enhance the non-heme absorption from plants by 85%. Consume a palm-size portion of iron-rich foods 4-5 times per week to maintain iron levels.

*Cook your iron-rich vegetables. Cooking plant-based iron foods such as spinach may improve iron bioavailability.

*Improve your digestion and boost your hydrochloric acid levels by drinking freshly squeezed lemon juice or apple cider vinegar in water 15 minutes before meals so you break down foods efficiently.

*Use pots and pans made from iron while cooking.

*Separate iron from calcium-rich foods. Consume foods containing substances that inhibit iron at least 2 hours away from an iron-rich meal or iron supplements. Calcium, oxalic acid, tannins and phytate-containing foods may all reduce iron absorption when consumed together.

• • Calcium-rich foods such as cow’s milk, cheese, yogurt and calcium supplements.
  • Oxalic acid s can be found in chocolate, tea, uncooked spinach and chard.
  • Tannins can be found in coffee, cocao, red wine, peppermint tea, and cranberries.

*Include iron-rich snacks and recipes like the ones we prepared for you in our Iron Rich Snacks e-recipe book.

*Soak, sprout, ferment and cook (where appropriate) foods containing phytic acid found in legumes (beans, lentils, chickpeas) and other wholegrains, nuts and seeds to limit phytates' effect on reducing iron absorption.

*Be aware of drugs such as antacids like Mylanta, antibiotics, and aspirin, which decrease iron absorption: separate iron supplements and iron rich foods from medications.

*Avoid self-prescribing supplements as too much iron can be toxic! See your naturopath for testing, advice on your iron status, and the quantity and best form of iron to take.

About the Author:

Kate Smyth provides sports naturopathy and nutrition advice and is a female-centric running coach. She founded the Athlete Sanctuary- a holistic healthcare clinic for athletes of all levels and sporting codes. She has been involved in sports for many decades and competed for Australia in the Commonwealth Games and Olympic Games marathons.