In Part 1 of the vegan series, we looked at the effects of vegan diets on different health parameters compared to omnivores, as well as highlight risks proposed by adhering to it. In part 2, I would like to shed some light on sports & athletic performance whilst adhering to a vegan diet and elaborate further on the deficiencies present thereof. Lassen uns beginnen…
Sports Caloric Requirement
Athletes in general require more energy than the average Joe, where many hours are spent in daily training. Endurance athletes are of particular interest (running, cycling, combat sports), as they struggle with insufficient caloric intake predisposing them to poor performance & a number a health issues . The stem of insufficiency is multifactorial; a badly structured diet is one cause, and one I want to discuss.
Endurance sports require a great deal of training, something akin to 2-4 hours on daily basis, even more at times. This type of training demands high caloric intakes, namely a crapload of carbohydrates . It is not uncommon to see endurance athletes eating 3000-4000 Kcals per daily only to sustain their bodyweight.
As previously mentioned, these athletes find difficulty in securing enough calories of their day-to-day needs. To that end, training under hypocaloric conditions for prolonged periods of time elevates cortisol levels and lowers the immunity which puts the athletes in harm’s way, as well as hinder their performance . It goes without saying, that it is important to structure the athletic diet correctly, that is vegan or omnivore.
Keeping that mind, vegan diets are characterized by high-fiber low caloric-dense foods that decrease absorption and increase satiety; this further complicates the acquisition of sufficient calories to maintain bodyweight, let alone an increase thereof   . In a sense, vegan diets put the athletes at higher risks for running into these problems on the long run, when contrasted with an omnivorous diet, which puts them one step further away from attaining their goals.
I want to briefly explain how macronutrient composition of vegan diets is not optimal by any stretch of the imagination, especially when all components of the diet are considered. By that I mean looking at the diet as a whole, which is crucial, as it allows us to understand the interaction between optimal nutrient demands and supply from vegan foods.
Carbohydrate acquisition as a whole is not a particular problem for vegans, as their diet is mainly comprised thereof, and is the main fuel for endurance-type sports, but they have to contend with high fiber intake, which as previously explained, is quite satiating.
Protein intake on the other hand is hindered significantly as vegan sources are scarce in qualitative and quantitative protein. At most, 54% digestibility is achieved from whole-food vegan proteins, (discussed here). That said, the recommended protein intake for endurance athletes is somewhere between 1.2g-1.4g /kg of bodyweight . I believe this to be little (for reasons that are beyond this article), and would suggest using Lyle McDonald's recommendation of 1.4g-2.0g /kg of bodyweight from his Protein book.
This value increases further, when athletes are training under hypocaloric conditions to preserve Fat Free Mass (FFM), which we now know vegans are more predisposed to . In any case, acquiring 1.2g-1.4g /kg of digestible protein is quite the task for vegan athletes, and must be supplemented from soy, rice & hemp powder in some.
Lastly, Fat intake on its own is no obstacle; the recommended intake is 0.5g-1.5g / kg of bodyweight. That roughly equals 30% of total caloric intake, and can be easily achieved via nuts, and oils.
Putting everything together, we ought to think that vegan athletes would need to mostly consume legumes, oats, and soy to push themselves as close as possible to the recommended protein intake, however they will also be consuming a ton of fiber alongside of it making them full faster. In turn, they’re not only dealing with the possibility of under-eating protein, but also with insufficient consumption of carbohydrates to maintain performance and (or) weight.
Especially heavy class athletes where 150-200g of protein may be required. Keeping in mind that I am only addressing endurance-type athletes where lower protein intake is recommended when compared to strength and power athletes, whose recommendations may well exceed 2.0g /kg of bodyweight  .
Essentially, vegan athletes or gym-goers must find ways around the Need to eat so much of high fiber foods, not having the appetite for it, and acquiring sufficient nutrients for optimal sports performance. It is quite a hassle to say the least, and implies a sort of food selection restrictions in order to attain these recommended values within reasonable bounds.
This concludes part 2 of the series. In part 3, I'm going to shed more light on the micronutrient deficiencies vegans contend with. Talk soon...
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