Minnesota Vikings running back Adrian Peterson argues that professional athletes are “modern day slaves.” “People might laugh at me for saying this, but I feel like a slave,” Peterson contended. “Sure, there’s six or seven-figure annual salaries, but what about the working conditions? We have to play outdoors most of the time—in the heat, cold, rain or even snow. Meanwhile, most of our fans are sitting at home with their feet up, snacks and drinks at hand. They’re benefiting from our suffering.” “And how many other jobs are there where 200+ lb. guys get to beat on you and it’s...