Cold water therapy

Cold water therapy is increasingly popular in Australia, particularly among athletes and wellness enthusiasts. A survey indicates that many Australians are adopting cold water immersion practices, with many using it for muscle recovery, mental health benefits, and overall well-being. According to Pursue Performance, approximately 82.6% of users engage in cold plunges 5-7 times per week, highlighting its regular use in personal health routines.

In my hometown of Torquay, cold water therapy boomed during COVID lockdowns. Groups such as “Torquay ocean waders” became conduits for community connection through ocean dipping and then coffee sipping outside the local Salty Dog café. This sense of community, based on an ethos of adventure, social connection, and a positive attitude, has grown to 1800 members in just three years, offering a supportive network for all.

The number of local female participants in this group intrigued me. I initially wondered if the group’s growing popularity was more about connection than the benefits of cold-water therapy. However, over time, the scientific evidence supporting and validating the health benefits of cold-water therapy has grown, providing reassurance and confidence in its effectiveness.

The menopausal transition adds another layer of complexity to health and fitness. Hormonal changes can affect metabolism, energy levels, and body composition. Despite sound nutrition and plenty of exercise, women in this life stage often complain of central weight gain.

Over 75% of Australian perimenopause or menopausal women will experience vasomotor symptoms (hot flushes and night sweats). Many women also experience sleep disturbances, mood changes and fatigue, as mentioned in our blog.

Cold water therapy is linked to improvements in exercise recovery, hormonal balance, and the management of symptoms such as hot flushes associated with menopause. This knowledge empowers women to take control of their health and well-being.

Cold water therapy can offer many benefits for women.

  1. Regular exposure to cold water can help reduce inflammation.
  2. In a study conducted at the University College of London, women reported cold water therapy reduced levels of anxiety, mood swings and depression.
  3. Cold water therapy can improve your immunity. Following exposure to cold water, the body releases catecholamines such as epinephrine and norepinephrine, which stimulate the immune system.
  4. Cold water immersion post-exercise for active women can aid muscle recovery, reduce soreness, and enhance overall physical resilience.
  5. Cold water therapy has also been suggested to reduce the frequency and severity of hot flushes.
  6. Regular exposure to cold water therapy may reduce cortisol levels associated with stress.
  7. Exposure to cold water is a habit spreading for the selective reduction of adipose tissue, improvement in insulin sensitivity, and is popular with anti-ageing proponents.
  8. Cardiovascular risk factors associated with heart disease are also reported to be reduced after just three weeks of cold-water therapy.

The evidence is clear- regular cold-water therapy holds many benefits for women, especially those experiencing symptoms associated with menopause.

Visit the Athlete Sanctuary for more personalised advice and resources. We support athletes in achieving their best selves through tailored strategies and a compassionate community.



AusPlay. (2022). Participation data for running and jogging. Retrieved from Australian Sports Commission.

Australian Institute of Sport. (2023). Nutritional considerations for female athletes. 

Bleakley, C. M., & Davison, G. W. (2010). What is the biochemical and physiological rationale for using cold-water immersion in sports recovery? A systematic review. British Journal of Sports Medicine, 44(3), 179-187.

Doets, J. J., Topper, M., & Nugter, A. M. (2021). A systematic review and meta-analysis of the effect of whole body cryotherapy on mental health problems. Complementary therapies in medicine63, 102783.

Esperland D, de Weerd L, Mercer JB. (2022).Health effects of voluntary exposure to cold water – a continuing subject of debate. Int J Circumpolar Health.

Janssen, H., Ada, L., Karayanidis, F., & McElduff, P. (2016). Ankle dorsiflexion strength after cold-water immersion in older adults: Implications for early stroke rehabilitation. Journal of Stroke and Cerebrovascular Diseases, 25(4), 867-872.

Miller, E. G., Maren, K., & Swanson, S. (2020). Cold-water immersion therapy and its effect on the alleviation of menopause symptoms: A randomized controlled trial. Journal of Women’s Health, 29(7), 951-958.

Smith, D. L., McHugh, M. P., & Allen, D. W. (2019). Cold-water immersion and recovery from exercise: Effects on menopause-related symptoms. Menopause, 26(8), 870-876.


Zinc deficiency and plant based athletes

Zinc deficiency is more common in plant-based athletes.  Fact is, zinc is the powerhouse that supports performance. And knowing how being deficient in zinc can affect your progress, is essential.

Most athletes understand zinc’s role in supporting the immune system and wound healing, and its requirement for a proper sense of taste and smell but few understand its role in muscle function. It is a nutrient that needs to be consumed every day as the body doesn’t naturally produce zinc.

In our blog Robust immunity in athletes we outline the common signs of zinc deficiency, including frequent and prolonged colds, acne, dermatitis, low stomach acid, poor digestion, fatigue, and white spots or bands on nails.

In our previous blog Am I Deficient in Zinc? we outline how the high demands of sports make the elite athlete more vulnerable to illness, meaning over 65% of athletes experience regular colds and infections that sideline them from events and consistent training.

Zinc’s homeostasis is tightly regulated by different transport and buffer protein systems. Exercise has been shown to modulate zinc blood serum and urinary levels and could directly affect zinc transport around the body. The oxidative stress induced by exercise may provide the basis for the mild zinc deficiency observed in athletes and could have severe consequences on health and sports performance.

Importantly for athletes, zinc has been found to affect protein and muscle formation and regeneration due to its effects on muscle cell activation, proliferation and differentiation.

Plant based athletes in particular need to be aware of zinc rich sources, and food containing inhibitors of zinc absorption.

For vegan and vegetarian athletes, wholegrain cereals and legumes provide the highest concentrations of zinc, generally in the range of 2.5–5.0 mg/100 g raw weight. As zinc is contained within the outer layer of grains, unrefined whole grains provide higher concentrations of zinc than refined grains (up to 5.0 mg/100 g, compared with 1.0 mg/100 g).

Wholegrain breads and cereals, rolled oats, brown rice, nuts, seeds, legumes, tofu, soy products and fortified breakfast cereals are important dietary sources of zinc for everyone, not just vegetarians.

Fruit and green leafy vegetables have much lower concentrations of zinc due to their high water content. The good news is there is no evidence of greater risk of being deficient if intake of plant based zinc sources are adequate.

Well-planned vegetarian diets can provide adequate amounts of zinc from plant sources. Vegetarians appear to adapt to lower zinc intakes by increased absorption and retention of zinc. The inhibitory effects of phytate on absorption of zinc can be minimised by soaking, heating, sprouting and fermenting. Absorption of zinc can be improved by using yeast-based breads and sourdough breads, sprouts, and presoaked legumes.

Studies on runners indicate a drop in serum zinc following exercise and a higher excretion of urinary zinc than in sedentary populations. Zinc is vital for skeletal muscle, a tissue whose main function is contraction, force and movement production. As your body actually secretes zinc through sweat, it is essential for athletes to monitor zinc levels often.

It is super important not to just rely on just supplements to increase levels of zinc in your body. The risks of long-term zinc supplementation can have other potentially detrimental effects such as displacing other minerals such as copper and iron needed to form hemoglobin, therefore, increasing the risk of developing anaemia.

Zinc requires a fine balance between adequacy and deficiency and therefore essential to seek advice from a qualified practitioner who can determine the best course of action to avoid issues.


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 www.https://


Walsh (2019).  Nutrition and Athlete Immune Health: New Perspectives on an Old Paradigm. Nov 6. doi: 10.1007/s40279-019-01160-3.

J.Hernández-Camacho, C. Vicente-García, D. Parsons, I. Navas-Enamorado (2020).  Zinc at the crossroads of exercise and proteostasis.  101529, ISSN 2213-2317. .

Woodbridge, P., Konstantaki, M., & Horgan, G. (2020). Nutritional deficiencies in vegan runners: A comparison of actual versus recommended nutritional intake and dietary recommendations. Journal of Exercise and Nutrition, 3(3).

DE, A. K. (2020). Zinc supplementation. A must for Athletes. Science and Culture.

McClung, J. P. (2019). Iron, zinc, and physical performance. Biological trace element research, 188(1), 135-139.

Hepcidin and iron regulation

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 www.https://



Ganz, T. (2016). Hepcidin. Rinsho Ketsueki57(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 metabolism24(2), 177-187.

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. Nutrients12(12), 3866.

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 Nutrition8.

Pagani, A., Nai, A., Silvestri, L., & Camaschella, C. (2019). Hepcidin and anemia: a tight relationship. Frontiers in physiology, 1294.

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 metabolism24(2), 177-187.[/vc_column_text][/vc_column][/vc_row]

Low zinc symptoms

The high demands of sports make athletes more vulnerable to illness, with 65% of athletes experiencing regular colds and infections. Zinc is a key nutrient required for immunity and keeping an eye out for low zinc symptoms, may just make the difference between being sick or great performances.

It can be so frustrating to put in many months of hard training only to be sidelined during a taper or on race day by heaving lungs, debilitating fatigue, and a pounding headache. Sports performance is materialised through consistency, akin to writing a book, one page at a time. Forced breaks from training due to illness detract from progress and drains confidence. Not all athletes rest when unwell and opt to “push through” the illness only to experience prolonged symptoms and more disruption to competition. 

Building a robust immunity is all part of a holistic approach to coaching and training. So how do you minimise your risk of getting sick? 

There are many nutrients that contribute to a healthy immune system as discussed previously.

Athletes may be more susceptible to being deficient in zinc because exercise, particularly strenuous and endurance exercise, increases zinc requirements, encourages zinc loss through sweating, and changes zinc transportation and metabolism.  

In our opinion, zinc plays the most critical role in supporting athletes and immunity.

Zinc’s role in hormone control and immunity

Zinc regulates several crucial processes in both your innate and adaptive immune system. Being deficient in zinc can lead to athletes becoming more susceptible to respiratory illness, particularly in the colder months. 

Apart from zinc’s well-established role in immunity, this mineral, contributes to protein structure, regulates gene expression, metabolism and is the second most abundant trace element in the body after iron.  Zinc deficiency can impact an athlete through hormone dysregulation (testosterone, thyroid, and growth hormones to name a few) and may affect erectile function and fertility.

Zinc is essential to maintaining optimum performance due to its function in metabolism and healthy cell division – essential in repairing damaged tissues after you exercise.

Studies show being deficient in zinc can lead to a reduction in the number of fast-twitch muscle fibres and muscle mass and performance decline.  For Masters Athletes this is of particular relevance as aging is also associated with sarcopenia, the age-related loss of muscle mass, muscle strength, and physical performance.

Zinc also helps maintain blood sugar control and assists with muscle contraction during exercise, glucose metabolism, and glycogen storage.

Zinc also plays an essential role in antioxidant production by increasing antioxidant activity and inhibiting free radical production that may damage tissues, impact liver function, and prevent muscle exhaustion.

Low zinc symptoms

Apart from recurrent colds and other infections, there are many low zinc symptoms.

*Anxiety and depression

*Hormone imbalances

*Poor concentration

*Stomach pain and gas

*Slow healing

*White spots on nails

*Skin issues and acne

*Loss of appetite

*Loss or change of smell

*Changes in taste

Zinc rich foods

The most concentrated sources of zinc are contained in animal products, particularly meat, seafood and dairy.   Vegan and plant-based athletes may be more susceptible to zinc deficiency due to reduced dietary intake, lowered gastric acid (which is zinc-dependent) and higher phytate consumption.  Phytates found in plant-based zinc-rich foods such as legumes can inhibit zinc absorption. 

Soaking nuts and seeds and legumes prior to cooking is a great way to minimise this issue and allow for greater micronutrient absorption.

Iron absorption 

The gastrointestinal tract plays an important role in maintaining total body zinc homeostasis by regulating zinc absorption and excretion. In order to boost your absorption, the addition of a probiotic may be beneficial.

In certain situations, zinc supplementation may be recommended. The amount ingested, supplement form, and the timing of zinc matters. Speak to a naturopath or nutritionist with an interest in sport before self-prescribing. You’ll definitely want to avoid zinc toxicity. High zinc levels can have a detrimental impact on your performance through anaemia, copper and iron deficiency and unpleasant gastrointestinal side effects.

Zinc testing

Serum blood testing is used by some conventional practitioners to determine zinc levels in the body. Keep in mind 60% of zinc is stored in muscle and 30% in bone therefore serum may not be the best measure of zinc homeostasis.  A mineral test can be another alternative method of assessing zinc levels and is available through our clinic as explained here.

If you need help building a robust immune system, book an appointment with our naturopath.


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 www.https://


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If you’re training hard, but don’t feel like you’re improving your athletic performance, then enriching your gut health through choosing the best probiotics to complement your gut microbiome could be the missing ingredient.

What are probiotics?
Probiotics are live microorganisms, mainly bacteria, and yeasts, that naturally reside in your gut (microbiome) and convey a health benefit. Your microbiome typically contains over 1000 different organisms, both beneficial and pathogenic.

Because a healthy gut microbiome strengthens your immune system and enhances your recovery from fatigue and overtraining, taking care of your gastrointestinal system is vital. This will enhance your general health and help to improve your athletic performance.

We consume probiotics via gut-friendly fermented foods such as yogurt, kefir, kimchi, kombucha, and sauerkraut, and commercially produced supplements.

Probiotics shouldn’t be confused with prebiotics. Prebiotics are carbohydrates and fibres such as inulin and other fructo-oligosaccharides found in foods like artichoke, bananas, and asparagus. The microorganisms in your gastrointestinal tract use prebiotics as fuel.

Supplements called ‘synbiotics’ contain both prebiotic molecules and probiotic organisms.2 Synbiotics offer a dual-action strategy for even greater health benefits. A diet rich in pre and probiotic foods support your gut to develop a robust immunity.

Understanding probiotics for runners

As the popularity of ‘gut health’ supplements for athletes increases, a basic knowledge of the assortment of beneficial probiotics in your supplement is helpful.

Probiotics are classified by their unique microorganism strain, which includes the genus, species, subspecies (if applicable), and an alphanumeric strain designation.

The seven core probiotic genera are Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Bacillus, Enterococcus, and Escherichia.

Lactobaccillus rhamnosus, Lactobaccillus acidophilus, and Saccharomyces boulardii are common commercially produced probiotic and yeast species. This ‘probiotic tree’ diagram highlights several commercially available probiotic strains.

Research on specific probiotic strains has expanded our knowledge of the health benefits and targeted treatments of probiotics for athletes. However, probiotic supplementation may not be appropriate or necessary for all athletes.

Probiotics for Runners

Certain probiotic species impart significant anti-inflammatory effects within your gut. In particular, Lactobacillus strains produce lactate, which is then converted into short-chain fatty acids by your gut bacteria. Butyrate is a pivotal short-chain fatty acid for intestinal homeostasis due to its anti-inflammatory properties and beneficial effects on intestinal cells, gut barrier function, and permeability.

Over thirty years of research supports the widespread use of Lactobacillus rhamnosus GG (LGG) for common gut-related issues such as diarrhoea, antibiotic use, infections, e.g., Clostridium, irritable bowel syndrome, inflammatory bowel disease, respiratory tract infections, and allergies in athletes.

Studies also show certain probiotics can improve vitamin D levels in athletes.

LGG along with L. acidophilus, and B. bifidum improve exercise-induced gastrointestinal symptoms. In fact, almost 60%of runners and endurance athletes who train intensely experience gut microbiome upsets and unwanted symptoms. Probiotics offer relief by supporting immune function and intestinal cell proliferation and function, as well as shortening the duration of gastrointestinal symptoms.5

Probiotic strains interact favourably with other probiotic species in the microbiome to improve the overall balance and composition of beneficial bacteria in your gut. For example, Lactobacillus fermentum (PCC) can increase the Lactobacillus genus seven-fold after 11 weeks of supplementation.

Probiotic supplements can help regulate blood sugar levels and maintain energy for training and performance. Also, yeast probiotics such as Saccharomyces cerevisiae are widely used to suppress the overgrowth of Candida or thrush fungal infections.

Lastly, new research demonstrates that probiotics can enhance sports performance. Runners taking Bifidobacterium longum (OLP-01) for five weeks significantly increased their running distance in a timed test. Bifidobacterium longum (OLP-01) also provided other health benefits such as increasing the abundance of gut microbiota in the runners.

There are a few final points to keep in mind before you add probiotics to your diet.

First, the quality of your probiotic supplement may vary significantly. Be careful about your choices as the label “probiotic” doesn’t necessarily mean this option will be suitable for your microbiome.

Second, a probiotic combination or an inappropriate supplementation duration may exacerbate unwanted symptoms in some situations. Therefore, it’s vital to consume high-quality, well-characterised live probiotics that deliver a therapeutic dose over an effective length of time.

Finally, the best probiotics for endurance athletes are selected case by case to improve your performance, recovery, immune and gut health. Be sure to seek professional advice for the most suitable probiotic therapy for your training and health circumstances.

Unsure if a probiotic supplement could help you?
Speak with Athlete Sanctuary’s sports naturopath and nutritionist about your health and sports performance goals today.

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 www.https://


  1. Hill C, Guarner F, Reid G, Gibson GR, Merenstein DJ, Pot B, et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol 2014;11:506-14.
  2. World Gastroenterology Organisation. Probiotics and prebiotics. 2017.
  3. Capurso, L. (2019). Thirty years of Lactobacillus rhamnosus GG: a review. Journal of Clinical Gastroenterology53, S1-S41. doi: 10.1097/MCG.0000000000001170
  4. Leite, G. S., Student, A. S. R. M., West, N. P., & Lancha Jr, A. H. (2019). Probiotics and sports: A new magic bullet? Nutrition60, 152-160.
  5. Salarkia, N., Ghadamli, L., Zaeri, F., & Rad, L. S. (2013). Effects of probiotic yogurt on performance, respiratory and digestive systems of young adult female endurance swimmers: a randomized controlled trial. Medical Journal of the Islamic Republic of Iran27(3), 141.
  6. West, N. P., Pyne, D. B., Cripps, A. W., Hopkins, W. G., Eskesen, D. C., Jairath, A., … & Fricker, P. A. (2011). Lactobacillus fermentum (PCC®) supplementation and gastrointestinal and respiratory-tract illness symptoms: a randomised control trial in athletes. Nutrition Journal10(1), 1-11.
  7. Gaziano, R., Sabbatini, S., Roselletti, E., Perito, S., & Monari, C. (2020). Saccharomyces cerevisiae-based probiotics as novel antimicrobial agents to prevent and treat vaginal infections. Frontiers in Microbiology11, 718.
  8. Lin, C. L., Hsu, Y. J., Ho, H. H., Chang, Y. C., Kuo, Y. W., Yeh, Y. T., … & Lee, M. C. (2020). Bifidobacterium longum subsp. longum OLP-01 Supplementation during Endurance Running Training Improves Exercise Performance in Middle-and Long-Distance Runners: A Double-Blind Controlled Trial. Nutrients12(7), 1972. doi:10.3390/nu12071972 
  9. Probiotic professionals


Vitamin D deficiency

Vitamin D deficiency has consequences well beyond bone health.

Vitamin D is gold.

Vitamin D is so important to the body, immune cells, brain, colon, breast, and other cells have the ability to also activate it locally when required. Although labelled a vitamin, calcitriol (bio-active vitamin D) acts more like a hormone within the body. It is involved in many essential functions well beyond bone health.  Vitamin D is critical for inflammatory modulation, hormonal and immune functions as well as cardiovascular, mental health and pancreatic function. The active form of vitamin D interacts with receptors in the intestine, bone, brain, heart, immune cells and skeletal muscle.  Vitamin D functions as a modulator of up to 1000 genes involved in cellular growth and protein synthesis.

Vitamin D plays an important role in an athlete’s health, training and performance.

Studies show it may even be necessary for optimal muscle function and performance as muscle performance is impaired by suboptimal vitamin D status. Deficiency induces atrophy of fast twitch muscle fibers, impairs calcium uptake and prolongs time to peak contractile tension and relaxation. Studies also show Vitamin D deficiency may delay rehabilitation from injury.

In sporty pregnant women, low vitamin D levels are linked to pre-eclampsia, gestational diabetes and adverse pregnancy outcomes. Vitamin D also plays a part in regulating insulin, blood sugar balance and thyroid hormones. Research shows that a deficiency of vitamin D is associated with a high risk of thyroid antibodies, which are found in individuals with autoimmune thyroid disorders.

Vitamin D is most commonly known in the athletic community for its influence on bone health and prevention of bone injury. Vitamin D influences bone health by upregulating expression of genes that enhance intestinal calcium absorption, and reabsorption by the kidneys along with increasing bone-building cell activity. Studies show calcium absorption significantly increases when vitamin D levels are sufficient. Calcium absorption is reduced to 10-15% with low vitamin D levels and stress fracture risk significantly increases.

Typically, 80% of our vitamin D is obtained from the sun and 20% from food sources.

Signs of Vitamin D deficiency

  • fatigue and tiredness
  • lower back pain
  • recurrent colds and infections and poor immunity
  • stress fractures
  • heaviness in the legs
  • recurrent injuries
  • muscle pain, weakness, poor muscle contraction and relaxation
  • mental health issues, low mood, seasonal sadness and depression
  • hormonal imbalances and PMS
  • anaemia and low iron
  • pale floating stool
  • photosensitivity

According to Sunsmart Australia, one-third of Australians are low in Vitamin D.

10 Reasons your vitamin D is low

Vitamin D can be made by our body when skin is exposed to sunlight through a complex activation process, however, what many people fail to realise is that this process doesn’t always occur efficiently or reach levels required for optimal health. Vitamin D production may vary depending on the time of day of sun exposure, season, cloud cover, smog, latitude, skin pigmentation, age, and sunscreen use.

We often see patients with low levels of vitamin D despite being out in the sun daily. There are several reasons why vitamin D levels drop despite sunlight exposure.

1. As vitamin D is fat-soluble and stored in fat cells, individuals with low body fat, may be disposed to vitamin D deficiency as their storage tank is smaller.

2. Activation and production of vitamin D are inhibited by magnesium deficiency, inflammation, and excessive use of sunscreen.

3. Individuals with any form of malabsorption issues, liver or kidney issues, coeliac’s disease, Crohn’s, vegans, and thyroid issues can be prone to deficiencies.

4. Anyone with a history of anaemia should also be aware of the bidirectional influence between iron and vitamin D. The activation of vitamin D in the kidneys requires iron-containing compounds ferredoxin reductase and ferredoxin. Iron deficiency may therefore contribute to the inactivation of vitamin D. Vitamin D deficiency may also be associated with higher hepcidin (a pro-inflammatory mediator) in the liver.  Hepcidin will elevate ferritin stores and down-regulate intestinal absorption of iron from food and impair storage iron release. Hundreds of athletes have used our handy anaemia tool to help determine the likely risk of having low iron or anaemia.

5. Diets containing limited seafood, eggs or dairy such as vegan diets may also reduce vitamin D intake.

6. Insufficient direct UVB exposure (due to smog, cloud cover or latitude), early- or late-day training, indoor training, geographic location further away from the equator and sunscreen use (SPF of 15 lowers vitamin D synthesis capacity by 98%).

7. Disruption to the microbiota and gut inflammation may also affect the availability of vitamin D.

8. In addition some individuals may find it difficult to increase their vitamin D levels if they have low antioxidant status.

9. Medications such as anticonvulsants, corticosteroids, cimetidine, theophylline, statins or the weight loss drug orlistat.


As a general guide, Osteoporosis Australia recommends most people should have levels of at least 50 nmol/L at the end of winter, which means people may have higher levels during summer (60-70 nmol/L). However, in order to maintain optimal health, athletes should aim for serum levels over 90 nmol/L ideally between 100 and 130 nmol/L.


Daily sunlight exposure on your skin especially on large areas such as the back, chest, legs and arms (25-60 minutes in winter) without suntan cream, is a great way to keep levels topped up. Athletes living in southern states of Australia and New Zealand need 30 minutes of direct skin exposure (springtime) on large areas of skin such as back, arms, chest or legs closer to midday. Athletes living closer to the equator may require 15 minutes before 10 am. During this time avoid putting sunscreen on, then for the rest of the day, cover up. Lunchtime exercise with as much skin exposure as possible (within decency) is a great way to give yourself a vitamin D fix, especially in winter months.

Get tested biannually- before winter and again in spring.

Consume vitamin D-rich foods on a daily basis such as oily fish like cod, salmon, sardines or tuna, egg yolks, sun-dried mushrooms, and fortified milk, butter and fortified cereals. Some individuals may benefit from cod liver oil which also contains vitamin A and essential fatty acids.

When levels are low, take a quality supplement in the correct dosage range and a probiotic. Certain probiotics such as Lactobacillus rhamnosus LGG and Lactobacillus plantarum enhance levels synergistically.

Obtain adequate magnesium-rich foods such as spinach, pumpkin seeds, almonds, black beans, oyster mushrooms, avocado, figs, yogurt or kefir and banana. Chocolate also contains magnesium.


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 www.https://

Mineral testing for athletes

Mineral and heavy metal testing can help to gain a better understanding of what metals may be impacting on health and what minerals are required to increase to enhance performance and overall health. Optimal nutritional balance is essential for the function of every cell and system in your body.  Obtaining feedback on mineral absorption is just one of the benefits of mineral testing for athletes.

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.

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.

Do you want to know more about Robust Immunity?

Before we dive into how to maintain robust immunity in athletes, let’s do a quick recap on how our immune system works.

The immune system is a busy network throughout our entire body including cells, vessels, lymphoid tissue, nodes, nodules, bone marrow and organs.

Bone marrow is where millions of new blood cells are produced every day. Bone marrow also serves as the site where cells are stored and matured before they enter the circulatory system.

Our immune system would not be complete without the gut-associated lymphoid tissue (GALT) – and Peyer’s patches in the small intestine.  Nearly 80% of our immune system is actually based in the digestive tract.

The thymus gland is a small gland known as the “seat of courage” and is located behind the breastbone. Our thymus helps regulate the immune system and is a storage tank for immune cells such as lymphocytes and monocytes responsible for eradicating viruses.

Our spleen is an oval shaped mass of lymphatic tissue which acts as a large blood filter. It recycles iron, captures and destroys pathogens and initiates the maturation and release of immune system when the body requires it (e.g. to fight infections).

Our lymph nodes act as a filtering system for the clear fluid called lymph which contains waste and immune cells. The lymphatic vessels act as the super highway carrying lymph between the 600 lymph nodes in our body located in our limbs, armpits, abdomen and groin.

Lymphatic nodules also contain lymphatic tissue and are positioned on mucous membranes in our respiratory system and gastrointestinal tract, tonsils and adenoids.

The immune system has many lines of defence.

 Our immune system is equipped with a multi-tiered response approach. A healthy immune system is always ready (24-7) to battle with foreign invaders.

The immune system includes our first line of defence which acts like the bouncers of your body deciding what can come in and what can’t such as the skin, mucous membranes, gastrointestinal tract and secretions like mucous, acidic vaginal secretions, bile, gastric acid (HCL), saliva, tears, and sweat.

The next line of defence kicks in when the bouncers have gone on a smoko and a pathogen is detected by the body. This part of our system also houses our infection-fighting cells such as our natural killer cells and phagocytes which act like Pac-men against microbial invaders. Our immune system also releases antimicrobial proteins such as complement and interferon which interfere with virus replication and protein which co-ordinate cell-to-cell communication. This part of the system deals with viruses, fungi, parasites etc.

Our immune system also keeps a record of every germ it has ever defeated so it can recognise and destroy the microbe quickly if it enters the body again.

Maximise what’s needed for robust immunity in athletes

In addition to enjoying a balanced wholefoods diet containing real foods rich in colour and vitality colourful rainbow on your plate, there are key foods to include in your diet you want to enhance your immune system.

The big guns

Vitamin C builds resistance to infection and stimulates immune cells and proteins such as interferon which help eradicate viruses. Vitamin C rich foods include veggies such as red capsicum, spinach, parsley and sweet potato. Fruits such as kiwi, berries, paw paw, pineapple citrus, guava, broccoli, mango, and currants are great sources of vitamin C.  Rosehip, Camu Camu, and Kakadu plum provide concentrated forms of vitamin C and can be found in powdered forms such as Wild C.

To optimise absorption vitamin C is best ingested with bioflavonoids. Lots of foods rich in vitamin C also contain bioflavonoids but they can also be found in celery, garlic, red onions, garlic, grapes, apricots and green tea.  In some circumstances, it is beneficial to supplement vitamin C. Vitamin may cause gastric upset in large doses. Dividing the doses throughout the day can reduce the side effects.

Zinc is responsible for supporting immune cell production and proliferation which fight off infections such as viruses. Common deficiency signs may include frequent colds, extended recovery periods, poor wound healing, low stomach acid changes in smell or taste and white spots on nails.

Zinc is lost through perspiration and displaced when other nutrients such as iron and copper are high as they share a common carrier in the body. Zinc supplementation should be under the guidance of a qualified practitioner to get the right dose and timing correct because high doses can impact other nutrients ( iron and copper) which may then contribute to immune dysfunction.

Foods rich in zinc include pumpkin seeds, fresh local seafood shellfish and oysters, tahini, peanuts, liver, eggs, nuts and seeds and legumes. Just remember to soak or sprout legumes, nuts and seeds to break down the phytates that may bind to zinc and reduce zinc’s bio-availability.

Obtaining adequate protein will supply the amino acids for antibodies and immune protein production.

Keeping well hydrated is also important for our first line of defence. Ginger and lemon drinks are a great alternative to water.

Immune modulators

Vitamin D, A, E and selenium are important antioxidants, immune modulators and help maintain healthy mucus membranes.  Exposing your unprotected skin to direct sunshine for 15-20 minutes daily will help boost vitamin D levels. Vitamin A-rich foods include cod liver oil, orange coloured foods such as carrots, sweet potato and apricots and kohlrabi. Vitamin E is found in nuts and seeds (such as sunflower seeds), eggs, and dark green leafy vegetables. Selenium is rich in Brazil nuts, alfalfa, meat eggs, onion, garlic and broccoli.

Shiitake and reishi mushrooms and green tea are also supportive of the immune system and build robust immunity in athletes.

Look after your gut health with pre and probiotic rich foods (think fibre and fermented foods like kimchi, sauerkraut, kefir, tempeh, kombucha, and quality yogurt). Choline found in lecithin from soy, eggs, beef, pork, olives, and broccoli, assists with the formation of the mucosal layer in the respiratory system and gut.

Include herbs and spices in your cooking that support healthy immune responses. Turmeric, ginger, Ceylon cinnamon (Cinnamomum verum), Cayenne peppers, garlic, horseradish, parsley, garlic, onions, oregano and thyme are all good choices.

What to avoid for robust immunity in athletes

Avoid substances that reduce immune system function.

1. Studies show sugar reduces the capacity of white blood cells within 1 hour of consumption and can last for up to 5 hours afterwards. Sugar can also feed some pathogens. Skip the middle isles of a supermarket where the processed foods are and spend more time selecting fresh foods.

2. Avoid too much caffeine or other stimulants that will stress our nervous system, impact on sleep but also deplete stores of zinc, and magnesium which we need in times of stress.

3. Avoid excessive alcohol and it may also suppress the immune system.

4. Avoid late nights binging on Netflix and obtain adequate sleep. This means at least 8 hours per night ideally hitting the pillow before 10pm. Sleep deprivation can increase your risk of picking up infections and reduce robust immunity in athletes.

5. Avoid or minimise unnecessary stress. Focus on what you can control and let go of the rest. Your mindset matters in times of stress and unpredictability. Be as flexible as you can with everything including your training, work, family and routine. Stress heightens cortisol which in turn smashes your infection-fighting cells.  Consider ways of dispelling stress other than more exercise such as meditation, mindfulness, relaxing activities such as reading or creative activities and watching comedies rather than more bad news stories.

6. Avoid over-exercising. Keep your exercise balanced. Robust immunity in athletes requires regular exercise, however moderation is the key. Too much exercise of long duration and intensity can make athletes more susceptible to respiratory infections.  For more information on exercise and its impact on the immune system click here 

For further information on the suitability of these measures for your particular situation, contact us for an individual assessment.

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 www.https://

Natural immune support such as herbal medicines can provide effective solutions to athletes who suffer from recurring colds and flu’s and other immune issues. When most people think of issues for athletes they usually think of musculoskeletal injuries such as sprained ankles, pulled muscles, or knee pain, but a recent study suggested immunity issues cause up to 50% of disruption to training or performance in athletes.

According to research, exercise improves immunity at moderate intensity but impairs immune function at high intensity (and duration) making many endurance and elite athletes more susceptible to respiratory infections.  Infection, such as fever and fatigue, can weaken muscles, impair exercise, and predispose athletes to other injuries. For example, fever impairs coordination, muscle strength, and aerobic power while viral illnesses contribute to tissue wasting and muscle breakdown.

Drugs commonly used to treat the symptoms of infectious diseases have variable impacts. Antibiotics can cause diarrhoea and ongoing gut issues, antihistamines can cause sedation, and many ephedrine-containing compounds like Sudafed are prohibited during competition over certain amounts under the Australian (ASADA) and World Drug Agency Association (WADA) guidelines.

To explain this immunity phenomenon perhaps a recap of how the human immune system is set up may be helpful. There are two parts to the immune system, the Innate Immune System and the Adaptive or Acquired Immune System.

Innate Immune System

The innate immune system includes our first line of defence providing physical barriers such as the skin, mucous membranes, nasal hairs, and eyelashes.  Functional barriers such as the gastrointestinal tract and defence mechanisms such as secretions, mucus, bile, gastric acid, saliva, tears, and sweat also protect us.

This part of our system also houses our infection-fighting cells such as our natural killer cells and phagocytes which act like Pac-men against microbial invaders, and proteins such as tumour necrosis factor which program cell death and cytokines which play roles in cell-to-cell communication.

The complement system is an additional cascade of proteins that “complements” other aspects of the innate immune system. The innate immune system is always ready to battle with foreign invaders, irrespective of whether they have come into contact with the microbial invader before.

Acquired Immune System

The acquired immune system is a collection of cells called T and B lymphocytes, immunoglobulins produced by the lymphocytes, and cytokines that regulate the immune response. Through a complex pathway of intercellular interaction, immunoglobulins are produced after exposure to a new pathogen, so they can recognise the invader the second time around and have an inbuilt immunological memory and enhance the immune response accordingly.

Gut-Associated Lymphoid Tissue (GALT) is a collection of several types of lymphoid tissue that store immune cells, such as T and B lymphocytes and is our major defence mechanism against pathogens entering the digestive system.  Peyer’s patch is a collective of lymphoid cells attached to the gut lining which is the initiation of the immune response when an infection is detected.

Secretory IgA is another substance produced by the acquired immune system produced in all areas where a protective mucosal layer exists such as the digestive, respiratory and urinary tracts to provide front-line defence. It forms the backbone of our immune system because it protects the immunoglobulins from being destroyed and protects the immunoglobulins from invading microbes.

This part of the immune system provides long-lasting protection against anything it has encountered before. When the two systems (innate and acquired) combine, they form an incredible defence against the constant barrage of infectious threats an athlete faces each day.

How does exercise impact on immunity?

So let’s examine how exercise can affect immunity. There is a substantial body of knowledge suggesting moderate exercise of up to 60 minutes at 60% of maximum heart rate improves immune cell counts and salivary IgA concentrations. Studies also show that 61% of new runner’s report fewer upper respiratory tract infections after starting running.   However, there is always a flipside to everything and in the case of exercise, the term moderation is wise to observe.

Intense exercise and prolonged exercise greater than 60 minutes may reduce immunity. While there is no doubt hard efforts increase VO2 max, it also forces most athletes to transition from nose breathing to mouth breathing, bypassing the nasal hairs and turbulent flow that protect the lungs from pathogens.

Inhaling larger volumes of colder and drier air thickens the mucous and disrupts the mucociliary elevator which is like our own inbuilt elevator designed specially to clear mucus from the respiratory tract. Hence why many athletes find they need to do a fair bit of “hoiking” to clear the phlegm during hard efforts in cooler months, especially when coupled with the ingestion of proinflammatory and mucous-producing foods such as dairy, coffee and bananas.

As more foreign particles are deposited in the lower airways, the ability to clear them is diminished, and airway inflammation results. Studies show our natural killer cells and secretory IgA fall after intense or prolonged exercise. The key members of our acquired immune system are also affected by neutrophils and B cell function declining.

With repetitive hard and long sessions that most endurance athletes over the marathon, ultra-marathon, ironman, triathlon or cycling do on a regular basis, hormones such as cortisol, prolactin, adrenaline, and growth hormone are constantly elevated and these also impair cellular immunity.

While most upper respiratory infections start off as viral infections, athletes who develop symptoms that are ongoing may also have a secondary bacterial infection.

What can be done about an underperforming immune system?

Few athletes stop training because they get a few annoying sniffles.  When on a mission, athletes should always seek out a solution to overcome or manage the issue.

At this point, it may be wise to seek help from a healthcare practitioner. Natural medicine has plenty to offer in regards to boosting the soldiers of the immune system. Most people are aware of the immune cell turbo boost vitamin C, and zinc provide but what about nature’s little wonders?

Natural remedies such as garlic and horseradish, Andrographis, Echinacea, Cat’s claw and Astragalus can increase immune cell count and function, and anti-microbial herbs like Thyme, Garlic, Thuja, St John’s Wart or Pelargonium have antiviral and antibacterial properties.

Maintaining digestive system integrity and gut health through quality probiotics will also help support GALT and sIGA in the adaptive immune system. Herbal adaptogens also assist with improving immunity integrity and resilience to future invasions. As with any treatment, these options are not going to be a magic bullet, but they can certainly reduce the severity of the infection, reduce recovery time and get you back to what you love doing. We always suggest athletes listen to their bodies and if needed modify training loads and convalesce to some extent.

Many studies use incorrect dosage ranges and timeframes for herbal medicines, so the evidence may be unclear and confusing to the untrained eye. However, when used in the correct dosage ranges, herbal medicines are viable options for athletes with few side effects. Research shows that seeking treatment quickly can reduce the impact respiratory illness may have on athletic performance.

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 www.https://


Iodine and thyroid hormones

Iodine and thyroid hormones are essential to sports performance and yet many athletes are iodine deficient.

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 www.https://