Elite athletes are a diverse bunch. You can find a few of them who follow all sorts of trendy diets, including carnivore, at least for a while. But if we look empirically at what works best in competition the vast majority of winning athletes across all sports are omnivores.

https://www.8020endurance.com/the-80-20-nutrition-guide/

There are also several anecdotal reports out there of athletes who tried vegan diets and found they got injured more frequently, or recovered more slowly. Does that mean anything? Who knows. There are so many confounding factors that it's impossible to research this issue in a truly rigorous way.

There are a few such anecdotes listed here. I'm not endorsing this blog or any particular diet, just pointing out that we lack clear evidence based guidelines.

https://www.lonesomelands.com/new-blog/2019/9/16/t2amoscp1u1...