Practical advice for Vegan & vegetarian athletes and exercisers
Updated: Oct 31, 2019
Vegetarian diet has some health benefits. More specifically a vegetarian diet is associated with reduced risk of death from heart disease, cholesterol levels, blood pressure, low rates of type II diabetes, low body mass index and low risk of some cancers. However, avoidance of animal foods does not itself define a health-promoting diet that will support athletic performance.
Firstly, is needed to think about protein intake of the vegetarian and vegan athletes. It is more common for the vegetarian athletes to meet their protein requirements as egg, dairy and soya are high quality of protein and provide all the 9 essential amino acids. However, vegans exclude these foods and may therefore find it more challenging to meet their protein requirements. They need to eat more variation of plant protein sources until the end of the
day, to meet a good balance of the essential amino-acids, as the plant protein is incomplete (limiting in one or more essential amino-acids e.g. lysine, methionine) and does not contain all the nine essential amino acids. The only plant source of protein contains the 9-essential amino-acids in soya. Furthermore, plant proteins are less well digested than animal proteins
and an increase in intake of 10% is therefore suggested in the literature (1.3-1.8g/kg/d).
In terms of vegetarian/vegan individuals and fat there is some concern over the high ratio of omega-6 and omega-3 fatty acids. Omega-3 fatty acids
have anti-inflammatory properties where are as omega-6 FA are pro-inflammatory. Thus, a high ratio can have an undesirable effect on inflammation and immune function after exercise which can have detrimental effects on recovery and successive performance (Simopoulos 2008, Lanham 2011). Furthermore, the omega-3 from fish oil (EPA & DHA) have beneficial effects for heart and lung function, mental function and muscle growth, all of which have beneficial effects on performance. Plant based sources of shorter chain omega 3 fats can be included in the diet
and converted inti EPA & DHA, however this conversion can be poor.
Another issue in vegetarian/vegan athletes is the micronutrients intake. For example, iron required for synthesis of haemoglobin in blood and myoglobin in muscle and there an essential component in the transport and delivery of 02. The iron content of vegetarian diets is similar to that of omnivorous diet, but the bioavailability (absorption) is the issue (Venderlet and Campell, 2006).
Furthermore, plant sources contain non-haem iron which is less well absorbed than haem iron found in animal products. However, additional foods (e.g. vitamin C) can increase absorption. Also, athletes might be at risk of iron deficiency due to exercise-induced iron losses (Ostpjic and Ahmetovic 2008). Vegetarian and vegan athletes should therefore include iron rich plant food protein. Supplementation is not essential expect when there are low levels of serum ferritin or anaemia. A review of the effects of iron deficiencies on performance identified a strong causal effect of severe and moderate deficiencies on aerobic capacity and endurance performance. But many athletes show low serum ferritin without performance decrement.
Another macronutrient that you need to consider is zinc. Zinc is involved in immune function, protein synthesis and blood formation. Iron, zinc can be obtained from a
vegetarian diet but it is the absorption that is the issue. Furthermore, zinc loss increases during strenuous exercise and it may therefore be harder for vegetarians athletes to maintain zinc status. For this reason, vegans
are suggested to consume 50% more zinc than is recommended and might require supplementation (Fuhrman and Ferreri, 2010).
The last macronutrient, is B12 essential for proper nervous system function, normal metabolism of nerve tissue and of protein, fat and C
HO. Vegan, fruitarian or macrobiotic diets do not have any active source of vitamin B12. Vegetarian should eat soya and vegan should supplement with B12.