Plant-based diets and athletic performance

The past few years, plant-based diets have gained in popularity. They are recommended in various weight management programs and they are the choice of environmentally conscious individuals, animal right supporters and various religious practices. Plant-based diets are also the choice for many professional and amateur athletes alike.

Despite the initial concerns on malnutrition or performance related issues from the past years, the current increasing number of successful careers of vegetarian or vegan athletes has brought the plant-based diets into the spotlight. And although the science has not definitively demonstrated an advantage or disadvantage in the performance of the non-omnivorous over the omnivorous athletes, some of the initial concerns have been addressed by the leading-edge research.

Is a full vegetarian/vegan diet achievable by athletes and endurance athletes in particular? Is it safe? Is it performance enhancing?

There is not a right or wrong answer to the above questions because they are all individual based and each individual athlete is unique. However, some facts do exist. The official position of the American Dietetic Association supports the well-planned vegetarian (lacto-, lacto-ovo-) or total vegetarian (i.e. vegan) diet as healthful, nutritionally adequate and with potential benefits to certain diseases [1]. As far as sports performance goes, the American College of Sports Science does not differentiate dietary needs for the vegetarian or vegan athlete compared to the omnivore ones. However, it brings into attention the reduced bioavailability of plant associated proteins and the possible lower intake of vitamins B-12, D, riboflavin, iron, calcium and zinc in the vegetarian diets. Because these macro and micronutrients are crucial for optimal nutrition, performance and recovery, the American College of Sports Science suggests that plant-based diets of athletes (compared to meat-based diets) should have an increased quantity of specific food families in order to succeed higher enrichment and digestion of the above nutrients. Supplementation is also suggested [2].

When an endurance athlete follows a vegetarian or vegan diet, perhaps of highest importance is the consideration of protein digestion and bioavailability. An athlete may take enough protein from plant or animal sources for their energy and recovery requirements but the plant-based proteins are not as well absorbed as the animal proteins. More importantly many plant based proteins lack a complete amino acid profile or more specifically some key amino acids that are beneficial to athletes training strenuously. Therefore an athlete who depends on plant-based diets only, should take careful action to optimize their digestive tracts and increase their protein intake by 10% to account for the possibility of incomplete protein digestion [2]. Athletes should also consider their plant protein blends carefully to ensure the amino acid profile supports their training. In addition to protein bioavailability, the bioavailability of the iron that comes from the plant food sources is of importance. Iron stores in the vegetarian population are generally lower than the non-vegetarian despite the fact that their total iron intake is similar or even higher [3, 4]. So, when considering food sources, endurance athletes, and in particular female athletes, should consider the lower bioavailability of plant-diet derived iron. Additionally, vegetarian athletes need to take into account that the crucial vitamins B-12, B-2 and D, the bone strengthening calcium and the important mineral of zinc are lower in plant-based products [2, 5]. Therefore, in many cases of vegetarian athletes, careful planning and supplementation is pivotal for optimizing performance.

On a positive note, current knowledge, advanced food resources and innovative supplementation has come a long way. Numerous successful professional athletes have experienced tremendous benefits from plant-based diets with minimal issues of malnutrition or decreased performances. For example, appropriate combinations of plant-based proteins (like rice and pea) may provide a Protein Digestibility Corrected Amino Acid Score (PDCAAS) – used by USDA as a protein quality score – equivalent to the PDCAAS of whey protein.

Despite the fact that presently there is not enough scientific evidence to support benefits of one diet vs. the other, carefully scheduled plant-based diets seem to improve the mood, health, training, recovery and performance on race day for an increasing number of athletes. For example, Lauren Goss, a successful FE professional triathlete who is a multiple 70.3 Ironman distance champion, has recently converted to a vegan diet. She says that she could not be happier. Since eliminating meat, dairy, eggs and limiting gluten, she reports better sleeping, less digestive distress, brighter skin, faster recovery and high energy. No more bloating, full stomach or other digestive discomfort. She writes: “… as of Jan 1st, I decided to go completely vegan. It has been 9 weeks now and I feel better than I ever have”.

At the end of the day, You have the choice. You can plan accordingly. You can give it a try.



  1. Craig WJ, M.A., Position of the American Dietetic Association: vegeterian diets. Journal of American Dietetic Association, 2009. 109(7): p. 1266-82.
  2. American Dietetic, A., et al., American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc, 2009. 41(3): p. 709-31.
  3. Craig, W.J., Iron status of vegetarians. Am J Clin Nutr, 1994. 59(5 Suppl): p. 1233S-1237S.
  4. Hunt, J.R., Bioavailability of iron, zinc, and other trace minerals from vegetarian diets. Am J Clin Nutr, 2003. 78(3 Suppl): p. 633S-639S.
  5. Barr, S.I. and C.A. Rideout, Nutritional considerations for vegetarian athletes. Nutrition, 2004. 20(7-8): p. 696-703.