At the Winter Paralympics, athletes with prosthetics often modify them to fit their bodies more precisely. That has led to some competitors starting their own businesses to help fellow amputees.

U.S. snowboarder Mike Schultz will compete in Italy’s Paralympics Saturday wearing a prosthetic leg of his own design. So will 25 of his competitors.

Before the UFC holds an event on the White House lawn in June, some fighters are paying the FBI a visit. UFC fighters will lead a training session at the FBI Special Agent Academy in Quantico, Va., ...