Veganism is a relatively “new” diet that few North Americans adhere to. Some studies say that only 0.5 percent of the American population claim to be vegans. Inevitably, you will come across clients who–in search of a healthier diet and/or lifestyle–are (or want to become) vegan. It is therefore important to know what to look for when training your vegan clients.
Vegans typically do quite well within certain aspects of their nutritional needs. For example, micronutrients from fruits and vegetables are in abundance, relative to the SAD (Standard American Diet) diet of most Americans. Also, fiber intake is much higher amongst vegans than the general population due to the consumption of more whole grains, legumes, whole fruits, and vegetables–a diet of which has been linked to lower than average levels of colon cancer.
At the same time, vegan athletes face unique challenges.
Because we evolved eating animals (and not just the muscle meat of chickens, cows, and pigs, but the entire animal–from snout to tail), we have adapted to assimilate animal foods and extract more vitamins, minerals, and other nutrients from our animal food sources.
As a result, the body competes with fewer anti-nutrients, which bind up minerals and make them harder to absorb by the body. These include phytic acid, lectins, saponins, and so on and are typically found in grains and legumes. They pass, unassimilated through the gastrointestinal tract, and are never digested and utilized.
This is not to say your client shouldn’t eat fruit and vegetable sources of proteins, vitamins, and minerals. That said, there are ways to make these types of food sources more easily assimilated by the body, which I will discuss later in the article.
Simply, athletes require more nutrients than sedentary people. This goes for macronutrients as well as micronutrients. Vegan athletes are no different from omnivorous athletes, but they need to pay particular attention to the following nutrients that are commonly deficient in a vegan diet:
Vitamin B12 (a.k.a. Cobalamin) is essential for the normal metabolic function of each cell in the body and most notably affects the following areas:
- Cobalamin is a necessary co-factor in the production of energy from fats and protein.
- Vitamin B12 is necessary for the growth and replication of cells.
- Bone marrow needs adequate vitamin B12 to keep up with the rapid growth and reproduction of its cells.
- Cells lining the gastrointestinal tract (the larynx, intestines, and bowel) require vitamin B12 for their growth and rapid replication.
- Vitamin B12 plays an important role in nervous system function.
- Vitamin B12 helps enzymes convert substances in the body to a more desirable form for either disposal or use.
There are no non-animal sources of B12, so even the most die-hard vegan will admit supplementation of this vital nutrient is necessary.  Fortunately, it’s easy to buy B12 supplements and many (too many!) foods are fortified with B12.
Be cognizant of any complaints from your vegan athletes in regards to tingling in the extremities, nerve pain or numbness. Nerve damage due to B12 deficiency may be irreversible. If you’re unsure, consider having your client get a blood test. The gold standard blood test to determine B12 deficiency is the methylmalonic acid (MMA) test.
There are essentially two types of iron in the diet: heme and non-heme. Heme sources are found in animal products and are more easily assimilated by the body. Non-heme iron is found in grains, nuts, vegetables, and fruits. Some iron is even transferred through your cooking utensils, like your cast iron skillet, for example. The problem with non-heme iron is its poor absorption in the gut, due to the anti-nutrients we discussed earlier. You can suggest that your client take in adequate vitamin C, which greatly improves iron absorption in the gut. Usually vegans could get abundant vitamin C from citrus fruits and dark, leafy greens.
Getting enough iron is an especially important concern for menstruating female athletes. If females aren’t taking in enough iron through diet and are losing iron in their blood during menstruation, anemia could occur, diminishing performance and impeding health.
Thankfully, many foods are fortified with iron. A good multivitamin (especially a women’s multi) will have adequate iron. If your vegan athlete’s progress has stalled or gotten worse, consider asking her to have a few blood tests done to measure iron stores (ferritin) and anemia markers.
Creatine is found mainly in animal products. Because vegans don’t eat animals, they don’t get exogenous creatine from their diet. At the same time, no foods are fortified with creatine, so supplementation is recommended for some types of athletes. This is more applicable to athletes in explosive sports, where ample creatine has been shown to improve power output in short bursts.
Carnitine is found primarily in meat and milk, and assists with fat metabolism. Though not typically deficient in a vegan diet, its production may be inhibited by vitamin C deficiency. Iron deficiency can also decrease carnitine synthesis.
There is some controversy over carnitine supplementation and a vegan diet. Carnitine is an amino acid derivative that is synthesized from the essential amino acids lysine and methionine, both of which are commonly deficient in poorly controlled vegan diets. It is made in the liver, kidneys, and brain. Vegans tend to have less carnitine in their blood as a result of decreased consumption of meat products, but mostly, scientists aren’t sure whether this is a cause for concern. I just mention this for you to be aware.
Calcium, iodine, zinc
Many foods and non-dairy milks are fortified and supplemented with calcium, iodine, and zinc. The problem is, these minerals tend to get bound to anti-nutrients found in grains and legumes (primary sources of protein in vegans); and as such, are not readily absorbed from the gastrointestinal tract. Typically, legumes are deficient in tryptophan and methionine, while grains, nuts, and seeds are low in lysine and isoleucine. Complete proteins can be created by combining legumes with grains, nuts, and/or seeds. For example:
- Beans and rice
- Peanut butter sandwich with whole-grain bread
- Cornbread and chili beans
- Hummus and whole-wheat pita bread
For many years, people believed that these had to be eaten in the same meal, or the proper amino acids wouldn’t be combined. We now know that is not accurate; simply eating those different foods throughout the day is sufficient.
Consider having your vegan clients soak, sprout, and/or sour their grains and legumes.
Why soak your grains and legumes? In a word, phytates. Phytates (a.k.a. phytic acid) bind minerals, making them bio-unavailable to your body. Zinc, iron, phosphorus, magnesium, and calcium get bound to phytic acid and pass right through you, decreasing digestion and assimilation. This also causes the leaching of calcium from bone in an effort to maintain normal blood calcium levels.
By soaking these foods in water (some people also use an additional acid, like lemon juice or apple cider vinegar), your client can help reduce some of the phytic acid by activating the enzyme phytase, which breaks down phytic acid through soaking and increases absorption in the GI tract.
Training wise, vegans are certainly capable of anything omnivores are and need no modifications. However, if you have a client who has recently changed to a vegan diet (or any other diet for that matter), and you notice considerable decline in their performance during your time together, don’t rule out malnutrition.
Signs to be on the lookout for:
- More easily fatigued.
- Frequent illness.
- Difficulty recovering from the previous workout, even though the volume/intensity hadn’t changed significantly.
The deleterious effects of a poorly managed vegan diet may not become evident for months, as iron and B12 stores in the body take months to become exhausted.
Don’t be shy to ask about changes in diet, even if you’re not sure how to go about making the necessary suggestions to your client. It helps to develop a network of other professionals (nutritionists, doctors, physical therapists, massage therapists, etc.) you can refer to when dealing with issues outside your comfort zone.
Recommended articles on handling nutrition and your clients:
- Can Personal Trainers Give Diet and Nutrition Advice to Clients? by John Berardi
- Help! My Clients Won’t Follow My Nutrition Advice by Jonathan Goodman
- How Trainers Can Advise on Questions About Supplementation by Eric Bach
 Orlich MJ, Singh PN, Sabate J, Fan J, Sveen L, Bennett H, Knutsen SF, Beeson WL, Jaceldo-Siegl K, Butler TL, et al. Vegetarian Dietary Patterns and the Risk of Colorectal Cancers. JAMA Intern Med 2015.
 Casey A, Greenhaff PL. Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance? Am J Clin Nutr. 2000 Aug;72(2 Suppl):607S-17S.
 “Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets,” J Am Diet Assoc. 2003;103:748-65.