The case against the vegan athlete

I want to preface this post with a caveat: Though hard, I do think it is possible to be a successful athlete while adhering to a vegan diet. A vegan diet, when properly monitored, can provide an athlete with an adequate source of protein and most other nutrients needed to succeed and thrive as an athlete. At a minimum though, you will probably have to supplement some vitamins and minerals that you may not be getting from a vegan diet such as calcium and B-12.

I am also not going to address in any depth the moral concerns that many, myself included, have about eating meat. The way most animals are raised for food is certainly rife with unspeakable horrors, which are the product of this countries desire for cheap food. Factory farming is certainly one of modern civilizations moral blind spots that most people chose to ignore by having other people do the killing for them behind the walls of a slaughter house.
I do think there is a middle ground, where animals can be raised in a much more ethical way. The real suffering that happens in the life of factory farm raised animals is not that they meet the end of their lives on the floor of a slaughter house, but the torturous conditions that these animals live their live in.

Most people do not want the little spare time in their life consumed by turning food preparation into a fanatical religion. Endurance athletes face a protein demand approximately double that of a normal individual. During periods of heavy training or caloric restriction for purposes of weight loss, that demand is closer to triple that of a normal individual.  Limiting your intake to plant based sources severely hinders your ability to get enough high quality protein in your diet. As an athlete, limiting your dietary choices can be like shooting yourself in the foot at every meal.  

Protein needs of the endurance athlete

Proper protein intake is essential for humans to remain healthy. Amino acids are the building blocks our bodies use to make proteins, enzymes, neurotransmitters, hormones, and various other functional compounds within the body. It can also contribute to our daily energy expenditure, especially when carbohydrate stores are intentionally or unintentionally limited during training.
As an endurance athlete, your protein intake should be 1.2g to 1.8/kg/day. As mentioned before, during periods of heavy training load or caloric restriction, your intake should be closer to 2.0g to 2.4g/kg/day to make sure you are not loosing muscle mass in the process.
A 150 lb athlete should be shooting for about 100g of protein a day durning a normal training load. That breaks down into 4-5 feedings containing 20-25g of protein. That is certainly doable but takes some discipline to make sure you’re getting enough and breaking it down into doses that your body can process effectively. In addition to all the detrimental health effects that the general population experiences due to protein deficiency, athletes with an inadequate intake of protein will stunt the physiological changes they are trying to produce by training. Signaling your body to increase mitochondrial density (the product of endurance training) doesn’t get you very far if you don’t give your body the building blocks to facilitate mitochondrial protein synthesis.

The differences in animal and plant based proteins

Not only do you need enough protein, but you also need enough of the right amino acids, especially the essential amino acids our body can not reconfigure from other amino acids. One of the advantages animal based proteins have over most plant based protein sources is that they are high quality or complete proteins, meaning they contain a balanced amino acid profile. As long as you are taking in enough animal proteins, you don’t have to be concerned about being deficient in a particular amino acid.

Except for soy, plant based proteins by their nature are incomplete in their amino acid profiles. You can think of these proteins as the light emitted by florescent lighting compared to natural sunlight. Plant based proteins provide an incomplete spectrum of amino acids (again, soy being the exception). One way to try an obtain a balance of amino acids is to consume complimentary proteins sources, such as rice and beans that can cover the missing amino acids from each other.

Another issue with most plant based proteins is the bodies ability to breakdown and utilize them. There have been a few attempts at coming up with a standard for which to compare the nutritional quality of different protein sources. None of them are perfect but taken together they can provide a good basis from which to compare protein source. The standard metric that is in use today is the Protein Digestibility Corrected Amino Acid Score (PDCAAS).
Animal based protein sources and soy rank very high on this scale given their complete amino acid profiles. Plant based sources such as wheat or peanuts rank very low. The body can not utilize the protein from low quality sources as effectively as those from high quality sources due to limitations in their digestibility and their amino acid profiles.

Vitamins and minerals

Those following a vegan diet may also find themselves deficient in specific vitamins and minerals, B-12 and calcium predominantly. Low B-12 levels can not only cause nerve damage but can inhibit red blood cell production, causing pernicious anemia. Calcium deficiency increases the risk of osteoporosis and can exacerbated in female athletes experiencing amenorrhea. Luckily, B-12 and calcium deficiency can be easily remedied by supplementing them in the diet.

Problems with soy

While the supplementation of soy protein can aid in providing a complete spectrum of amino acids to a vegan diet, soy does have its detractors. Google “problems with soy” and you will probably never touch soy again. The hormonal affects that the phytoestrogens (chemicals that mimic estrogen) found in soy may have on health is probably one of the larger problems, though the research seems to be far from unequivocal.
According to the USDA, as of 2015, 94% of soy beans grown in this country are genetically modified (GM). While the fears or GM crops have for the most part gone unrealized, they do involve a large reliance on pesticides to increase crop yield which comes with its own problems which I won’t address here.
Certainly, animal based protein sources are not without their own issues. high intake of red and processed meats seem to have the largest negative health affects associated with them, though these health risks seem to be greatest in those that are genetically predisposed to certain health issues such as colon cancer.


One has to ask about the benefits of adhering to a diet that requires supplements and careful monitoring of nutrients to remain healthy. As I said previously, though hard, I do think it is possible to adhere to a vegan diet and be a successful athlete.
With all the challenges that athletes face, from finding enough time to train, careers and relationships that maybe compromised by the demands of training and competition, a vegan diet is a self imposed hurdle that can hobble your health if not carefully monitored.

The moral implications of a diet that includes animal based proteins are a bit out of the scope of this blog post. For those who share my concerns about the implications of factory farming, a shift towards ethically raised farm animals can be a huge step towards more moral food choices.
If you are concerned about the ethics of eating meat, and more especially if you are not, I’d recommend taking a listen to Sam Harris’s conversation with Paul Bloom. Their conversation on the moral implications of eating meat and vegan/vegetarianism starts at 1:14:00 of the podcast).