[3] The pair trained at the VSS Lokomotiv sports club and competed internationally for the USSR.

[6] Belousova and Protopopov began the forty-year Soviet/Russian gold medal streak in pair skating, the longest in Olympic sports history, from 1964 to 2006.

[7] Those were the pair's final appearances at major international competitions but they continued to compete within the Soviet Union until 1972.

[7] In September 2015, they renewed their long-standing tradition of skating in a charitable exhibition in Boston, Massachusetts, at an event called "Evening with Champions".

Dick Button stated: "The Protopopovs are great skaters not only because they were the finest of Olympic champions, but also because their creative impact was extraordinary.

"[8] Figure skating writer and historian Ellyn Kestnbaum stated that they "raised by several degrees the level of translating classical dance to the ice".

[5] According to Kestnbaum, Protopopov identified romantic heterosexual love as the meaning he and Belousova conveyed in their pair skating.

[9] Born on 16 July 1932,[2][10] Protopopov was raised by his mother, a professional ballet dancer, and his stepfather, the poet Dmitry Tsenzor.

[11] On 24 September 1979, Protopopov and Belousova defected to Switzerland while on tour and applied for political asylum.

[11] They attended the 2014 Winter Olympics in Sochi, Russia, and performed their last exhibition dance in 2016, when Protopopov was 84.