Is there any evidence for this? Other than possible joint pains, which are likely no worse than doing a regular factory job, and sports like NFL and fighting where hitting each other is the point, and are probably more comparable to gladiator sports than something like basketball or baseball.

I suspect the better fitnes that sports persons have in most other sports, combined with the above average income, means they almost certainly have better health than the average person, even after adjusting for the fact that they likely have better physical health genes.