were filled throughout the Games. Recent Games Rio de Janeiro in Brazil hosted the 2016 Summer Olympics, becoming the first South American city to host the Olympics, the second Olympic host city in Latin America, after Mexico City in 1968, as well as the third city in the Southern Hemisphere to host the Olympics after Melbourne, Australia, in 1956 and Sydney, Australia, in 2000. The preparation for these Games was overshadowed by controversies, including political instability and an economic crisis in the host country, health and safety concerns surrounding the Zika virus, and significant pollution in the Guanabara Bay. However, these concerns were superseded by a state-sponsored doping scandal involving Russian athletes at the Winter Olympics held two years earlier, which affected the participation of its athletes in these Games. The 2020 Summer Olympics were originally scheduled to take place from 24 July to 9 August 2020 in Tokyo, Japan. The city was the fifth in history to host the Games twice and the first Asian city to have this title. Due to the COVID-19 pandemic, the then-Japanese Prime Minister Shinzo Abe, the IOC and the Tokyo Organising Committee announced that the 2020 Games were to be delayed until 2021, marking the first time that the Olympic Games have been postponed. Unlike previous Olympics, these Games took place without spectators due to concerns over COVID-19 and a state of emergency imposed in the host city. Nevertheless, the Tokyo 2020 Olympic Games featured many memorable moments and feats of technical excellence. One star of the games, the US gymnast Simone Biles, gracefully bowed out to focus on her mental health, but later returned to claim an individual bronze medal. Norway's Karsten Warholm smashed his own world record in the 400m hurdles. Sports There has been a total of 42 sports, spanning 55 disciplines, included in the Olympic programme at one point or another in the history of the Games. The schedule has comprised 33 sports for recent Summer Olympics (2020); the 2012 Games featured 26 sports because of the removal of baseball and softball. The various Olympic Sports federations are grouped under a common umbrella association, called the Association of Summer Olympic International Federations (ASOIF). Qualification Qualification rules for each of the Olympic sports are set by the International Sports Federation (IF) that governs that sport's international competition. For individual sports, competitors typically qualify by attaining a certain place in a