The Paralympic Games are the second largest sporting event in the world. More than four thousand athletes participated at the Rio 2016 Paralympic Games. Considering the staff, volunteers, accommodation, transportation and overall scheduling that would be needed to host such an event, it would be nearly impossible for one city to host both the Olympic and Paralympic Games simultaneously. Under the agreement between the IOC and IPC, it was determined that the Paralympic Games will always take place following the Olympic Games in the same host city.