Slavery is not a choice. Playing college athletics is a 100% choice. At my work I occasionally have to give up weekends, give up sleep, give up nights. Sometimes I am so mentally exhausted when I come home that I can't enjoy the rest of my day. Am I slave too? You are arguing one thing, and then comparing to slavery (something totally different) so you can paint it with an ugly word (slavery).
Is the definition of a slave working for someone else in a situation where you could leave anytime you wanted to? Are we that desperate to victim-make and victim-champion?