Here's a list that I know of:
Tom Whelan ( First to ever do it)
Here's another source:
Jim Thorpe. He played in MLB between 1913-1919 and in the NFL between 1920-1928.
Click on the link below to see a list of athletes that played multiple sports.
Almost all of them
3630 professional athletes.
Including all professional sports from around the world, 2,734 athletes went pro in 2009.
There are more than 1,000 professional athletes in Europe.
there are 1000's of disabled of athletes in the world, that compete in sports
There number of the professional black athletes is in the tens of thousands. Most of the athletes disciplines is dominated by the black athletes from different parts of the globe.
all athletes are educated, but the amount of it varies.
There are many things about professional athletes to know, if that's what you mean.
over a million
Loads!!! i think the question is how many pro athletes smoke !!!