You know how long distance runners dont work out their upper body....what about sprinters?

Sprinters should absolutely be working their arms. Driving the arms is just as important as driving the legs. Look at most of the greatest sprinters. Bolt is kind of a freak of nature, but he definitely works his arms too. Consider Maurice Green, Dennis Mitchell, Dwain Chambers, Walter Dix ... arms to match their legs. They need that balance to be explosive and run fast.