Thinking about going vegan as an athlete?

Being a high performing vegan athlete requires a well planned diet to ensure optimal nutrients are being obtained. However it is possible to thrive eating a solely plant based diet. Below is a quick overview for my top tips to get the most out of your performance and health as a vegan athlete.

What is a vegan diet?

Veganism is a diet that excludes all animal products, including dairy, eggs, seafood & meat (11). It is becoming more popular primarily for health, environmental and animal welfare concerns (13). This diet is a hot topic in sport because some high-profile athletes have attributed their diet with enhancing their performance such as tennis champion Venus Williams (5)  and Formula 1 5-time champion Lewis Hamilton (3) .

How a vegan diet can improve health

A number of studies show that a well-thought-out plant based vegan diet may lower the risk of some cancers and cardiac diseases and improve microbiome diversity(12). A diverse microbiome with a large number of microflora is a key element to vitality, longevity and healthspan. I am a firm believer that almost all disease starts in the gut. Vegans also generally have higher levels of short chain fatty acids, higher fibre intake and better blood glucose and lipid levels (13).

VO2 max is an important consideration particularly for endurance athletes as higher levels are correlated to increased performance. VO2 max affects how well oxygen is transported through the blood to fuel muscles. A cross sectional study shows that there was no noticeable difference between omnivores, vegans and lacto-ovo-vegetarians (7). This is important to note as a vegan diet is unlikely to impede on endurance performance.

Research shows that vegans are less likely to be deficient in iron, calcium and protien, which may be surprising to some. However there are a number of key nutrients vegans need to think about how they will obtain as research shows the following nutrients can be more difficult to obtain.

How a vegan diet can affect performance

Nutrient Deficiencies

If a vegan diet is not well planned it is common for vegans to suffer from a number of nutrient deficiencies which can be serious (12). The most concerning nutrient deficiencies for vegans are B12, selenium and iodine. In comparison to omnivores research shows vegans may have lower levels of iodine, selenium, omega3 and B12. Deficiencies are evident even when the diet fits in line with government dietary guidelines (4).

Vegan sources of most common nutrient deficiencies:


Plant foods high in iodine include sea vegetables such as nori, kombu and kelp. Iodine is important for thyroid function, producing hormones and metabolism.


Plant foods high in omega-3 include chia seeds, hemp seeds and soy beans. Omega-3 is important for brain health, research shows that it has a protective effect against many neurological diseases and disorders such as dementia, bipolar, mood swings, depression and anxiety. It is also important to get adequate amounts for fetal health when pregnant, optimal levels were shown to improve a babies health, intelligience and weight.


B12 is a well-known deficiency amongst vegans as it is almost impossible to get adequate amounts from plant sources and therefore supplementation is necessary to prevent failure to thrive and neurological damage. Only 10 7 % of vegans “met the recommended intake of vitamin B12 from food (Benham et al., 2021).


This nutrient can be harder to adequate amount of on a vegan diet, shitake mushrooms and soy are the best vegan sources. This nutrient is vital for brain, liver and muscle health, cells require choline to preserve structural integrity. Signs of deficiency include brain fog, fatigue, nerve damage, sore muscles, issues with mood and more.


Plant foods high in selenium include Brazil nuts, wheat germ, sunflower seeds and lentils. Selenium has numerous roles in the body, it is important to have adequate levels to reduce the risk of heart disease, immune function, fertility and thyroid health. Research shows that it can also act as a gentle chelator of the heavy metal mercury.


If you are concerned about a deficiency the first step is to get tested to double check. It is important to cycle supplements as minerals and vitamins work in synergy. I buy most of my vitamins and supplements from iHerb, one of the largest and most affordable online dietary supplement retailers in the world. CLICK HERE to check them out.


One of the biggest concerns athletes have is getting enough  complete protein on a vegan diet. There are a number of amino acids that are only available through animal products such as leucine, lysine, threonine, tryptophan, and methionine (13) . Soy is the most complete vegan protein. However it is important that a diverse range of plant foods are consumed such as beans, buckwheat and nuts to obtain a wide variety of amino acids (8). Plant protein may also be harder to digest and may contain anti-nutrients which may affect optimal muscle repair and strength which is particularly important for endurance athletes (9).  A study that came out in 2020 shows that vegans are at a higher risk of bone fractures than vegetarians, pescatarians and omnivores (10).


Vegans tend to have reduced stores of creatine which is important for optimal functioning of the mitochondria. The mitochondria are the powerhouse of the cell generating most of the ATP required for energy. Creatine is particularly important for optimal high intensity performance (9).


Vegan athletes are less likely to achieve adequate calories and healthy fats (1) , therefore it is recommended to increase the consumption of calories through nutrient rich plant foods such as avocado, chia seeds, hemp seeds, a variety of nuts and legumes. Chia seeds are good for omega 3 (6) , hemp seeds for omega 3 and protein, seaweed for iodine and Brazil nuts for selenium (4) .



Although research shows that there are benefits to following a vegan diet, it must be well planned to ensure adequate nutrients, particularly as an athlete with increased nutrient requirements (2). Athletes should be tested for potential nutrient deficiencies these potential issues to ensure optimal levels are maintained (13) .




  1. Benham, A., Gallegos, D., Hanna, K., & Hannan-Jones, M. (2021). Intake of vitamin B12 and other characteristics of women of reproductive age on a vegan diet in Australia. Public Health Nutrition, 1-11.
  2. Boldt, P., Knechtle, B., Nikolaidis, P., Lechleitner, C., Wirnitzer, G., & Leitzmann, C. et al. (2018). Quality of life of female and male vegetarian and vegan endurance runners compared to omnivores – results from the NURMI study (step 2). Journal Of The International Society Of Sports Nutrition, 15(1).
  3. Davies, D. (2021). Lewis Hamilton’s Shares His Plant-Based Daily Diet. Men’s Health. Retrieved 9 April 2022, from,go%20hard%2C%22%20says%20Hamilton.
  4. Fallon, N., & Dillon, S. (2020). Low Intakes of Iodine and Selenium Amongst Vegan and Vegetarian Women Highlight a Potential Nutritional Vulnerability. Frontiers In Nutrition, 7.
  5. Gomez, J. (2021). Try Venus Williams’ Go-To Protein Shake Recipe That Keeps Her Fit. Women’s Health. Retrieved 9 April 2022, from,aka%20a%20vegan%20who%20cheats.
  6. Kulczyński, B., Kobus-Cisowska, J., Taczanowski, M., Kmiecik, D., & Gramza-Michałowska, A. (2019). The Chemical Composition and Nutritional Value of Chia Seeds—Current State of Knowledge. Nutrients, 11(6), 1242.
  7. Nebl, J., Haufe, S., Eigendorf, J., Wasserfurth, P., Tegtbur, U., & Hahn, A. (2019). Exercise capacity of vegan, lacto-ovo-vegetarian and omnivorous recreational runners. Journal Of The International Society Of Sports Nutrition, 16(1).
  8. Reed, K., Camargo, J., Hamilton-Reeves, J., Kurzer, M., & Messina, M. (2021). Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies. Reproductive Toxicology, 100, 60-67.
  9. Rogerson, D. (2017). Vegan diets: practical advice for athletes and exercisers. Journal Of The International Society Of Sports Nutrition, 14(1).
  10. Tong, T., Appleby, P., Armstrong, M., Fensom, G., Knuppel, A., & Papier, K. et al. (2020). Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study. BMC Medicine, 18(1).
  11. Tuso, P. (2013). Nutritional Update for Physicians: Plant-Based Diets. The Permanente Journal, 17(2).
  12. Wirnitzer, K. (2020). Vegan Diet in Sports and Exercise – Health Benefits and Advantages to Athletes and Physically Active People: A Narrative Review. International Journal Of Sports And Exercise Medicine, 6(3).
  13. Wirnitzer, K., Boldt, P., Lechleitner, C., Wirnitzer, G., Leitzmann, C., Rosemann, T., & Knechtle, B. (2018). Health Status of Female and Male Vegetarian and Vegan Endurance Runners Compared to Omnivores—Results from the NURMI Study (Step 2). Nutrients, 11(1), 29.

If you’d like to increase your vitality, improve your health span and have more energy book an appointment with me here, I would love to work with you.

By nutritionist Chrissy