vitamin C

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://


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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. 


Best collagen for tendon repair

Choosing the best collagen for tendon repair can be challenging. There are so many to choose from. All collagen powders are not created equal. Understanding the different forms and their sources can be helpful when making your decision.  Keep in mind collagen can be helpful in the repair of tendons, bones and ligaments, improving skin elasticity and gut health.

Recent studies have helped to fine-tune dosage recommendations and nutrient combinations to enhance its effectiveness. As the quality and volume of collagen produced by our body reduces with age, master athletes may benefit from consistent supplementation.

What does collagen do?

Collagen is a major structural protein and building block made within your body. Collectively, collagen comprises 30% of the body’s protein as amino-acids, specifically glycine, proline, hydroxyproline and arginine.  Collagen provides structure and acts like glue to your skin, hair, skeleton, tendons, muscles, ligaments, corneas, teeth and blood vessels. Hydrolysed collagen is similar to gelatin but structurally varies. Collagen contains tri peptides whereas gelatin contains simple amino acid chains.  Peptide chains within collagen act as signalling molecules to fibroblasts which increase collagen, elastin and hyaluronic production. They also signal anti-inflammatory agents and increase the production of antioxidants.

There are 29 different types of collagen, all with slightly different roles but 80 – 90 % of the collagen in the body consists of types I, II, and III.  Together all forms serve the same purpose; to help tissues withstand stretching. Although all forms are essential in the body, research tends to focus on types I-III when it comes to athletes. Let’s explore these three types in a little more detail.

Type I  forms the reinforcing rods in bone, cartilage, tendons, teeth and connective tissue and is the most dominant form within the body making up 90% of all collagen. It is also the collagen that forms scar tissue and skin.

Type II (also known as hyaline or articular cartilage) is the major collagen in elastic cartilage and is the gel like substance designed to provide cushioning and allow joints to absorb shock. Its rigid macromolecules provide the strength and compressibility that allow it to resist large deformations in shape during movement.

Type III supports the structure of muscles, organs, and arteries.

Collagen and vitamin C for repair – the research evidence

Recent studies have also shown the combination of 500mg of vitamin C and between 5 – 15 grams of collagen is beneficial when taken one hour before exercise. Positive results do not appear to be dose dependent when within this range. Several studies including a study from the AIS (Australia Institute of Sport) showed significant improvements in achilles tendon injuries when taken for three to six months.

A 2017 study also demonstrated significant improvements in activity-related joint pain in 139 athletes,  positive changes to ankle function and pain following supplementation for sprains.  Collagen also reduces the risk of subsequent sprains for 3 months after supplementation.

Most collagen powders on the market are derived from shellfish, beef, chicken or pork. As a general recommendation, better quality collagen supplements are derived from grass-fed animals or wild-caught seafood. Vegans should be aware plants do not make collagen. There are currently no clinical trials that support bone broth as a reliable source of collagen peptides.

Vitamin C

Vitamin C converts proline and glycine to hydroxyproline.   Pre-clinical studies have also shown vitamin C has the potential to accelerate bone healing after a fracture, increased type I synthesis, and reduce oxidative stress.

Additional dietary intake of vitamin C-rich foods during rehabilitation may also be beneficial. Good sources include berries, red capsicum, broccoli, kiwi, guava, citrus, rosehip and indigenous foods such as camu camu, goji berry and Kakadu plum.

Other beneficial nutrients

Copper also plays a role in production as it activates an enzyme called lysyl oxidase that is required for maturation. Copper is found in beef liver, crab, oysters, sunflower and sesame seeds, cocoa powder, cashews, hazelnuts, peanuts, almonds and lentils.

Zinc helps with the production and activates a protein that remodels collagen during wound healing. Zinc is found in seafood, oysters, pepitas, nuts, poultry and meat.

Manganese activates enzymes such as prolidase that your cells use to make proline and gives collagen fibres their shape. Brown rice, oats, pineapple, peanuts, and pecans all contain manganese.

Amino Acids

Insufficient protein intake or overall energy intake impedes wound healing and increases inflammation to possibly deleterious levels. During the healing process, energy expenditure is increased, particularly if the injury is severe. Energy expenditure may increase between 15% – 50%, depending on the type and severity of the injury.

Given that muscle loss may begin from inactivity during an injury recovery phase within 36 hours and healing processes are heavily reliant on synthesis of collagen and other proteins, the importance of dietary protein should not be understated. If you are in the unfortunate position of being injured, protein intake of 2 grams/ kg of body weight per day is advocated.

Meat, poultry, seafood, dairy, legumes, and tofu are all excellent sources of amino acids. Plant-based athletes may combine protein sources to ensure all essential amino acids are available for protein synthesis.

In addition, specific foods rich in proline and glycine may be beneficial.

Proline is found in egg whites, wheat germ, dairy products, cabbage, asparagus, and mushrooms.

Glycine is found in the skin of pork or chicken and gelatin.

Making your own gelatin chews are an easy way to boost glycine intake.

Gelatin is what is used to set jelly and gummy lollies. Gelatin also contains proline, valine and glutamic acid.

Be wary of sugar!  Sugar interferes with collagen’s ability to repair itself and degrades collagen. It is therefore a good idea to limit your consumption of added sugar and refined carbs when injured for several reasons.

Please remember the guidelines provided in this blog are general in nature. If you are injured, you may benefit from individualised nutritional guidance to help you get back on track. Make 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://


Clark, K. L., Sebastianelli, W., Flechsenhar, K. R., Aukermann, D. F., Meza, F., Millard, R. L.,  & Albert, A. (2008). 24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain. Current medical research and opinion24(5), 1485-1496.

Dressler, P., Gehring, D., Zdzieblik, D., Oesser, S., Gollhofer, A., & König, D. (2018). Improvement of functional ankle properties following supplementation with specific collagen peptides in athletes with chronic ankle instability. Journal of sports science & medicine17(2), 298.

Frankenfield, D. (2006). Energy expenditure and protein requirements after traumatic injury. Nutrition in Clinical Practice21(5), 430-437.

Lis, D. M., & Baar, K. (2019). Effects of Different Vitamin C–Enriched Collagen Derivatives on Collagen Synthesis. International Journal of sports nutrition and exercise metabolism29(5), 526-531.

Praet, S. F., Purdam, C. R., Welvaert, M., Vlahovich, N., Lovell, G., Burke, L. M., & Waddington, G. (2019). Oral supplementation of specific collagen peptides combined with calf-strengthening exercises enhances function and reduces pain in achilles tendinopathy patients. Nutrients11(1), 76.

Shaw, G., Lee-Barthel, A., Ross, M. L., Wang, B., & Baar, K. (2017). Vitamin C–enriched gelatin supplementation before intermittent activity augments collagen synthesis. The American Journal of clinical nutrition105(1), 136-143.

Zdzieblik, D., Oesser, S., Gollhofer, A., & König, D. (2017). Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides. Applied Physiology, Nutrition, and Metabolism42(6), 588-595.


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://