Now I am not talking from a health or nutrition standpoint, but motivationally.
I struggle to call myself an athlete, but in any adventure I do, part of me feels that I am representing veganism and must do well. When I rode my bike cross-country (which ranks pretty low in physical difficulty) years ago I found that a number of people drew conclusions on veganism. 'Well, if you could do that and be vegan it must be okay' or my vegan friends who used me as an example, 'My friend Matt is vegan and he rode his bike cross country!
What do the rest of you think? If someone with an omnivorous diet gets tired at work or DNF's at a marathon no one says, 'maybe it is what s/he is eating.' But if a vegan exhibits either of those suddenly everyone is a nutrition consultant. During some low points on more than a few adventures I've drawn on this to motivate me: Must continue and not let veganism down...