Socialist Workers' Sport International was an international socialist sporting organisation, based in Lucerne. It was founded in 1920, and consisted of six national federations at the time of its foundation. Initially it was known as International Association for Sports and Physical Culture. Informally it was known as the Lucerne Sport International. It adopted the name SASI in 1926. The Austro-Marxist Julius Deutsch was the president of SASI.

The International Association of Red Sports and Gymnastics Associations, commonly known as Red Sport International (RSI) or Sportintern was a Comintern-supported international sports organization established in July 1921. The RSI was established in an effort to form a rival organization to already existing "bourgeois" and social democratic international sporting groups. The RSI was part of a physical culture movement in Soviet Russia linked to the physical training of young people prior to their enlistment in the military. The RSI held 3 summer games and 1 winter games called "Spartakiad" in competition with the Olympic games of the International Olympic Committee before being dissolved in 1937.