iron and energy production

Iron and energy production are integral to sports performance. When it comes to physical performance, many female athletes find themselves caught between balancing dietary preferences and ensuring that iron intake is adequate. This is particularly the case for plant-based athletes or athletes with limited intake of red meat.

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 www.https://


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 failure18(7), 762-773. 


energy boosting herbs

As interest in herbal medicines is increasing among athletes, we thought we’d share some insights from recently published medical journals on energy boosting herbs.

The area of sports performance and sports products can be confusing but by sharing evidence-based information, we hope to create greater awareness and empower you to make informed decisions. Please keep in mind, this information is general in nature and does not qualify as specific advice for your individual sport or health status.

Many sports products are underpinned by large marketing budgets, whereas many natural products demonstrate clinical results but unfortunately allocated limited research budgets in regard to their effects on sports performance.

Plants provide nutritious macro-nutrients such as carbohydrates and lipids. Herbal medicines also contain active compounds that reduce infections and inflammation. Their applications are very broad from improving cardiovascular health to balancing hormones. The most popular herbs contain antioxidant properties that play a role in reducing oxidative stress, enhancing muscle recovery and energy with intensive exercise.  Let’s investigate four of the herbs used by athletes namely Green Tea, Ginseng,  Turmeric, and Tribulus.

Green tea extract

Green tea extract (Camilla Sinensis) is often found in weight management and stimulating supplements. Green tea extract (GTE) contains polyphenols, and antioxidants reported to increase fat utilisation. The phytonutrients in green tea have also been shown to inhibit pro-inflammatory substances and improve tendon, cartilage and collagen in athletes.  Unfortunately, the majority of poor quality (yet widely available) GTE products do not declare their level of active ingredients and therefore provide very mixed results for athletes.

Dietary inclusion of GTE antioxidants is well supported.   A 2017 clinical trial involving 54 soccer players taking GTE demonstrated significant improvements in oxidative status over a six week period (Hadi,2017).  A subsequent study involving cyclists, demonstrated positive effects on neuromuscular function, reduced oxidative stress and muscle damage with cumulative exercise. Other studies suggest it may improve body mass and composition in athletes.

I encourage athletes to use GTE as a substitute for coffee with limited withdrawal side effects. Although the average cup of pure green tea usually contains around 25 milligrams of caffeine, this is considered to be low when compared to around 100-180 milligrams in a typical coffee.

Synopsis: Green tea extract is a great source of antioxidants. Clinical trials focused on weight loss do not include well-trained athletes and therefore the relevance of results remain questionable.  Whilst green tea is well researched by credible sources such as the Cochrane Review (Jurgens, 2012), in my opinion GTE supplements do not deliver significant weight loss benefits over and above a sound nutritional and exercise plan to warrant the marketing hype. Green tea is however a great alternative to coffee and absolutely delicious as a matcha latte or in bliss balls.


When considering herbs for sports performance, the ginseng family is widely studied and praised for its support of physical endurance. There are many different forms of ginseng. The root of Korean ginseng (Panex Ginseng) is widely recognised for its anti-inflammatory, antioxidant, immune enhancing and endurance performance benefits. It also contains vitamins A, B, C and E along with iron, magnesium, potassium, phosphorous and ginsenoside active compounds.

A 2018 study demonstrated ginseng’s anti-fatigue effects related to its reduction in creatine kinase and blood urea nitrogen. Other studies suggest that use over a nine week period may improve aerobic capacity,  (Vo2max), physical performance, lactate production and heart rate in athletes.

Its medicinal use extends to erectile dysfunction, libido, weakness, poor memory, cardiovascular issues, fatigue in menopausal women, and cognitive function.

Synopsis: Ginseng’s inclusion in nearly 8000 research papers in PubMed suggests this herb deserves consideration, especially in athletes with fatigue.


Turmeric Curcuma Longa is the most well-researched root in the world and is renowned for its antioxidant, anti-inflammatory and hepatoprotective coumarin agents.  In clinical practice it is widely prescribed for inflammatory conditions such as arthritic joint conditions, liver and digestive issues, cancer, neurodegenerative disease and autoimmune conditions.

Turmeric has benefits for marathoners, downhill runners, and weight trainers by attenuating muscle inflammation caused by training and competition by reducing inflammatory cytokines.  Some researchers suggest curcumin may serve as a more effective anti-inflammatory agent than ibuprofen during and following heavy exertion..

A study involving male master cyclists showed a significant reduction in advanced glycation end-products (AGEs) which are associated with stiffening of skeletal muscle, tendons, joints, bone, heart, arteries and lung with turmeric use.  A recent 2020 systemic review concluded turmeric before, during and up until 72 hours post-exercise, improved performance by modulating the inflammation caused by physical activity.

Synopsis: Turmeric’s appearance in over 15,000 published research papers provides credibility behind its anti-inflammatory capabilities for recovery and injuries.  Turmeric is generally well tolerated in therapeutic doses without significant side-effects. Sufficient levels of active curcumin are difficult to obtain through dietary intake alone and therefore supplementation may be beneficial for some athletes. Professional guidance around its bioavailability and quality is however imperative in order to obtain its reported benefits.


Tribulus Tribulus Terrestris gained popularity amongst eastern European male athletes for its reported ability to improve testosterone, muscle growth and libido in power and weight-lifting athletes. Tribulus is used medicinally for hormonal support in both men and women. Tribulus contains steroidal saponins, such as diosgenin and phytosterols with beneficial effects on reproductive, urinary and cardiovascular systems.

Many of the recent studies investigating the anabolic and androgenic action of Tribulus are poorly designed and provide conflicting results. A 2008 study was unable to reveal a significant variation or increased above the WADA cut-off limits testosterone. Another study on Australian rugby union players failed to use adequate therapeutic levels of Tribulus.

Synopsis:  Although considered a relatively safe herb by clinicians, this plant has been targeted for contamination with illegal substances in supplements. Some supplements containing Tribulus have led to positive doping control tests. Therefore this herb should be cautioned for elite athletes.   In our opinion further research is warranted before safe and effective recommendations of this herb for sports performance can be provided. As with all-natural medicines, just because they are “natural” does not necessarily imply they are safe or without side effects or interactions with other medications. Therefore, athletes should consult with a qualified herbal practitioner who is across drug controls before self-prescribing.

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://


Fernández-Lázaro, D., Mielgo-Ayuso, J., Seco Calvo, J., Córdova Martínez, A., Caballero García, A., & Fernandez-Lazaro, C. I. (2020). Modulation of exercise-induced muscle damage, inflammation, and oxidative markers by curcumin supplementation in a physically active population: a systematic review. Nutrients12(2), 501.

Suhett, L. G., de Miranda Monteiro Santos, R., Silveira, B. K. S., Leal, A. C. G., de Brito, A. D. M., de Novaes, J. F., & Lucia, C. M. D. (2021). Effects of curcumin supplementation on sport and physical exercise: a systematic review. Critical reviews in food science and nutrition61(6), 946-958.

Sellami, M., Slimeni, O., Pokrywka, A. et al. Herbal medicine for sports: a review. J Int Soc Sports Nutr 15, 14 (2018).

Machado, Á. S., Da Silva, W., Souza, M. A., & Carpes, F. P. (2018). Green tea extract preserves neuromuscular activation and muscle damage markers in athletes under cumulative fatigue. Frontiers in physiology9, 1137. 

For further information on the suitability of these options for your particular situation, book in for an individual assessment with our Sports Naturopath Kate Smyth here

Blood sugar

To keep your energy sustained, it is important to maintain blood sugar control. Natural blood sugar control is possible when done correctly and with professional guidance and supervision. When individuals fail to fuel themselves properly, they may experience reactive hypoglycemia (low blood sugar) or dysglycaemia (abnormal blood sugar levels) with an exaggerated insulin response. As a result, there is a subsequent dramatic drop in blood glucose, causing physical and emotional symptoms (see below). When blood glucose levels become unstable we can feel like we are on an energy roller-coaster throughout the day.

Symptoms can mimic other common issues such as anxiety or even menopause.

Symptoms of blood sugar dysregulation:

  • Nausea
  • Seeing flashes of light
  • Moodiness and “hangry” relief after eating
  • Negative attitude/ irritability
  • Exaggeration of relatively minor problems
  • Feeling emotionally flat or depression
  • Lightheadedness or dizziness
  • Sweating and flushes
  • Sugar cravings
  • Fatigue
  • Heart palpitations
  • Shakiness
  • Paleness
  • Cold/clammy skin
  • Poor concentration and memory

Thyroid issues, hormonal imbalances, or high exercise demands can exaggerate these symptoms, especially with inadequate fueling in between multiple daily training sessions. There are a number of simple steps that may help stabilise blood sugar.

1. Protein is essential to blood sugar stabilisation and should be included in every meal including breakfast. Quality protein can be found in lean animal meats (kangaroo, lamb, beef, chicken) and fish. Vegetarian options include tofu, tempeh, legumes, eggs, dairy, and high-protein grains such as quinoa, buckwheat and amaranth. Vegans and vegetarians must practice protein source combinations to obtain all the essential amino acids.. For example: consume chickpeas with brown rice.

Athletes should ideally consume 1.2-1.6 grams of protein/kilogram of body weight which equates to 60-80 grams of protein for a 50kg female and 90-128 grams for an 80kg male athlete per day. It is beneficial to have 20 grams of protein with carbohydrates within 30- 60 minutes of completing a training session. A good option is a smoothie with a scoop of protein powder (pea, brown rice or whey if tolerated), a small can of tuna or 2-3 eggs.

2. Carbohydrates
Intake of low GI (Glycemic Index) carbohydrates will help keep blood sugar levels more sustained, and energy levels consistent. A high GI carbohydrate will cause a surge in blood glucose, triggering a response from the pancreas. This can contribute to the symptoms described previously.

Good sources of complex carbohydrates include porridge, Bircher muesli, brown, basmati or wild rice, barley, oats, buckwheat, quinoa, amaranth, teff, rye, sweet potato, and root vegetables with skins on. Sourdough bread, corn on the cob, bananas, fruit smoothies with protein powder, and homemade muffins using wholemeal flours such as hemp, chia or buckwheat are all good options. Consuming carbohydrates with quality fats and soluble fibre also reduces the GI of foods.

3. Magnesium
Magnesium assists with blood sugar control by supporting healthy insulin secretion.

Magnesium is abundant in amaranth (a grain), pumpkin seeds, dark chocolate and raw cocoa, wholemeal bread, quinoa, firm tofu and dark leafy vegetables. It is also found in oat bran, brown rice, cooked spinach, avocado, coconut water, kale, legumes, sesame seeds and cashews.

4. Chromium
Chromium deficiency reduces your body’s ability to use carbohydrates for energy and raises your insulin needs. Chromium may enhance the effects of insulin or support the activity of pancreatic cells that produce insulin. Chromium is found in meats, fish, poultry, wholegrains, dairy, broccoli, cheese, mushrooms, asparagus, green beans, apples, bananas, grape juice and potato.

5. Probiotics
Probiotics especially those containing more than one species of beneficial bacteria may help regulate blood sugar by influencing the way the body metabolises carbohydrates by reducing inflammation and preventing the destruction of pancreatic cells that make insulin.

Maintaining energy throughout the day

  • Have regular meals throughout the day eating every 2 hours
  • Consume protein at every meal. Aim to make up at least 1/3 of your meal from protein
  • Stay hydrated by drinking water regularly (2-3 litres per day minimum)
  • Cinnamon, nutmeg, cloves, vanilla, stevia, and ginger can all be used instead of sugar to add sweetness to food.
  • Carbohydrates higher in fibre and from unprocessed sources are better
  • Consume carbohydrates within 30 minutes of completing a session
  • Fat reduces gastric emptying time and as a result, slows down the absorption of glucose from the meal. Consume beneficial fats with carbohydrates from raw nuts and seeds, fish, avocado and cold-pressed oils.
  • Increasing the acidity of food or meals will slow gastric emptying time. A simple tip is to add vinegar dressing to salad or vegetables.
  • Short-term supplementation of magnesium, chromium, probiotics or cinnamon, and other blood sugar-stabilising herbs and nutrients may be beneficial for some individuals.

Always seek help from a healthcare practitioner if your symptoms persist.

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://