We use only the authentic press agencies, and fulltime career journalists, since they have backgrounds and legal knowledge concerning usage. We bypass the freelancers, retired high school coaches, certified officials with pro cameras, etc. For pictures and video footage we almost always use Getty, AP, and Reuters.
If you have a book on the Shot Put for example, with a picture of Cantwell on the cover from a competition, then it's editorial, and you only have to pay Getty, not Cantwell. The same applies to CDs, the web, etc.
If you instead buy a picture of Mylie Cyrus from Getty, and put it on the cover of the Shot Put book, then one could make a legitimate argument that that is not news and not editorial and Mylie should be paid for a commercial license.
Also if you personally go to a public meet and shoot an anonymous kid, 18 years old or older, throwing the shot put, then put it on the cover, you do not have to pay anyone. The picture is that of a legal adult in a public place.