To make it short, veg*an athletes should follow the same recommendations as veg*ans that are not athletes. Indeed, several studies have been done on the topic and here I summarize the most important ones, stating which considerations have been done for each subject:
State of the art
Medical science has no final assessment on veg* diets and sport.
Little is known about the relationship between vegetarianism and
athletic performance.
More research is needed to answer some of the current concerns of
vegetarian athletes.
(Berning 2000)
Well-controlled long-term studies assessing the effects of
vegetarian diets on athletes have not been conducted.
(Barr 2004)
Iron intake
Veg* athletes must consume enough iron to meet their requirements. See below "Recommended readings" for more details.
Potential adverse effect of a vegetarian diet on iron status is based
on the bioavailability of iron from plant foods rather than the amount
of total iron present in the diet. Vegetarian and non-vegetarian
athletes alike must consume sufficient iron to prevent deficiency.
(Venderley 2006)
Other nutrients of concern
Besides iron, veg* athletes must pay attention to their intake of several other micronutrients. Again, see the "Recommended readings" for the recommended intake references.
Other nutrients of concern for vegetarian athletes include zinc,
vitamin B12 (cyanocobalamin), vitamin D (cholecalciferol) and
calcium.
(Venderley 2006)
Appropriate planning and programmed follow up are needed to monitor
vitamin B12, iron, zinc, vitamin D, riboflavin, and protein status.
(Borrione 2009; Fuhrman 2010)
Creatine
Veg* athletes might show lower creatine stores, thus a supplementation could be considered.
Muscle creatine stores are lower in vegetarians than non-vegetarians.
Creatine supplementation provides ergogenic responses in
both vegetarian and non-vegetarian athletes, with limited data
supporting greater ergogenic effects on lean body mass accretion and
work performance for vegetarians.
(Venderley 2006)
Veg* advantages
Veg* diets show several advantages: antioxidants intake is higher and thus can prevent oxidative stress.
Vegetarians have higher antioxidant status for vitamin C (ascorbic
acid), vitamin E (tocopher-ol), and β-carotene than omnivores, which
might help reduce exercise-induced oxidative stress.
(Venderley 2006; Zhou 2013)
Macronutrients
Macronutrient balance might be more favourable for veg*s since they eat a higher proportion of carbohydrates.
There are advantages to the athlete of consuming a vegetarian diet.
Vegetarian athletes usually consume a higher proportion of energy in
the form of carbohydrates. It is well documented that athletes,
especially endurance athletes, should be consuming a higher
proportion of carbohydrates in their diets to maximize muscle glycogen
concentration.
(Berning 2000)
Suggested readings:
