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Plant-Based Diet on Athletes Performance (does it really matter?)

In this episode of the AISTS Medicine Podcast, Emilio Valdes and James Dominey from the AISTS MAS class of 2020 discuss the plant-based diet on athletes’ performance.

According to a 2019 study by Bernhard, eating a plant-based diet provides more antioxidants that help neutralize free radicals, which are responsible for muscle fatigue, decreased athletic performance, and impaired recovery.

Emilio: Hello everyone, my name is Emilio Valdes, and I’m here with my friend James Dominey. How are you, Dom?

Dom: Hi Emilio… Hello everyone! I’m good and happy to be here…. How are you Emilio?

Emilio: I am good too, thanks for asking. So, thanks everyone for joining us for this AISTS medicine podcast, which will be looking at plant-based diets and its possible impacts on athletic performance.
What are your thoughts on this topic Dom?

Dom: Well it’s a super interesting topic… plant-based diets have had a lot of attention over the past few years, many people and some scientists believed them to be the cornerstone of a healthier lifestyle. We can watch documentaries like game-changers that preach about the health benefits of a plant-based diet, whilst in the world of professional sport there are many athletes that have turned vegan, like Lewis Hamilton, Daid Haye and Venus Williams, who subsequently rave about the performance benefits that they have obtained. However, there are also many critics who see this diet as just another fad without scientific evidence to back it up. This is a huge topic and we don’t have time to cover everything in this podcast, so lets just try and shed some light on the more controversial points that we have noted from our research

Dom: Firstly, for me, the biggest issue with a plant-based diet is the lack, or difficulty in obtaining, certain vitamins, minerals and nutrients required for optimal body function. A review of existing literature on vegan diets completed by Rogerson in 2017 indicates that a vegan diet generally appears to be lower in protein and fat as well as:

  • Vitamin B12
  • Calcium
  • Zinc
  • Iodine
  • Vitamin D

Any views on this Emilio?….

Emilio: What you’re saying might be true, But obviously supplements can be taken. Nowadays, People are taking supplements for many different purposes, so why not for this too?

Dom: OK, supplements are available, but you need to be careful so that the correct amounts are being consumed which can be complicated for athletes with no nutritionist. This is also true for antioxidants which are largely obtained from plant foods. A study completed by Kahleova in 2018, suggests that the body can overdose on antioxidants which can have a negative impact on insulin sensitivity and muscle

Emilio: Wo wo, hold on a minute. According to a study by Bernhard in 2019, eating a plant-based diet provides more antioxidants which help neutralize free radicals which are key to muscle fatigue, reduced athletic performance, and impaired recovery. And talking about recovery, what I’ve read is that eating meat supposedly increases inflammation, which can result in pain and negatively impact athletic performance and recovery. Studies seem to show that a plant-based diet may have an anti-inflammatory effect which could aid recovery times.

Dom: That’s all well and good, but as noted by Asker Jeukendrup in 2019, and many other doctors, inflammation is what you need to get better. Inflammation is a signal to turn on repair processes in the body and this will ultimately make you better. No inflammation, no improvement. What we do want to prevent is excessive inflammation during recovery. And tied in with recovery is the creation of additional muscle. Although you can find sufficient protein in plant-based products, and in some cases more on a weight-for-weight basis, plant-based proteins are inferior. According to a study by Phillips and van Loon in 2011, plant-based proteins miss essential amino acids which appears to be a primary trigger for Muscle Protein Synthesis.

Emilio: ok…. But what about endurance? Plant-based diets are better for increasing glycogen storage in the muscles and liver which ultimately delivers more energy and can improve endurance, as noted in research conducted by Jacobs in 1999.

Dom: Yes. But it is typical for vegans to eat more carbohydrates than omnivores which would automatically lead to higher levels of glycogen being stored in the muscles and the liver. This is nothing new, Emilio. In fact, endurance athletes, whether vegans or omnivores, would carb load before a race as it is known to increase glycogen levels and aid performance.

Emilio: OK… but an area where there is no argument is around the health benefits of veganism. Our friend Dr. Berhard mentions that plant-based diets, which are low in saturated fat and free of cholesterol can help to:

  • Lower blood viscosity
  • Improve arterial flexibility and diameter and
  • Remove plaque which gathers on arteries as a result of the extra fibre consumed in a plant-based diet.

Together these factors promote blood flow and the ability for oxygen to reach the muscles, which can improve athletic performance. Also I’ve seen that plant-based diets help reduce body fat which can be associated with an increase in the aerobic capacity or V02 max.
Another study completed by Boutros in 2020 seems to prove this. He studied 56 women between the ages of 21 and 30 years old. From this group, 28 were vegan and 28 omnivores for at least 2 years before the study was made. Both groups were comparable for physical activity levels, body mass index and muscle strength, however, the vegans had a significantly higher estimated VO2 max compared with omnivores.

Dom: OK, so it seems that there are pros and cons to a purely plant-based diet. Some benefits are irrefutable, whilst others do not appear to have the science to back up the claims. What do you think?

Emilio: Yes Dom for the first time we agree on something. It seems that there is not one diet identified as the best…. What is in fact really important is to have a balanced diet that includes all major food groups that can be adapted to the needs of each individual.

Dom: Well, I think that’s a good place to leave it for now. Thanks for joining us.

Emilio: Thanks! See you next time 🙂


  • Barnard, N., Scialli, A., Turner-McGrievy, G., Lanou, A. and Glass, J., 2005. The effects of a low-fat, plant-based dietary intervention on body weight, metabolism, and insulin sensitivity. The American Journal of Medicine, 118(9), pp.991-997.
  • Barnard, N., Goldman, D., Loomis, J., Kahleova, H., Levin, S., Neabore, S. and Batts, T., 2019. Plant-Based Diets for Cardiovascular Safety and Performance in Endurance Sports. Nutrients, 11(1), p.130.
  • Boutros, G., Landry-Duval, M., Garzon, M. and Karelis, A., 2020. Is a vegan diet detrimental to endurance and muscle strength?. European Journal of Clinical Nutrition,.
  • Phillips, S. and Van Loon, L., 2011. Dietary protein for athletes: From requirements to optimum adaptation. Journal of Sports Sciences, 29(sup1), pp.S29-S38.
  • Rogerson, D., 2017. Vegan diets: practical advice for athletes and exercisers. Journal of the International Society of Sports Nutrition, 14(1).
  • Tang, J., Moore, D., Kujbida, G., Tarnopolsky, M. and Phillips, S., 2009. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. Journal of Applied Physiology, 107(3), pp.987-992.
  • van Vliet, S., Burd, N. and van Loon, L., 2015. The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. The Journal of Nutrition , 145(9), pp.1981-1991.

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