The ambassadors have been selected in conjunction with the World Championships' Local Organising Committees according to various criteria, including not only titles but also the exemplary nature of their careers and their links with the host countries.

Chosen for the 48th World Artistic Gymnastics Championships, which are scheduled to take place in Qatar’s capital Doha from October 25 to November 3, are Japan’s Mitsuo Tsukahara and Belarus' Svetlana Boguinskaia.

Tsukahara was one of the mainstays of the Japanese team that dominated men's artistic gymnastics throughout the 1960s and 1970s.

The five-time Olympic champion - as part of the team event in 1968, 1972 and 1976, and on the horizontal bar in 1972 and 1976 - has been immortalised thanks to the vault that bears his name.

He performed it for the first time in 1970, bringing him his first individual world title.

During the course of his career, Tsukahara won nine Olympic and six world medals, including four world golds.

Boguinskaia's performances have been described as a "study in feline elegance".

It was under the Soviet flag that she won four Olympic medals at the Seoul 1988 Olympic Games, including gold in the vault and team competition.

The following year, Boguinskaia was crowned world champion in the individual all-around competition, as well as in the floor and team competition.

She won a third Olympic title with the Unified Team in 1992 in Barcelona having added two more world titles in 1991 by winning beam and team gold.

The ambassador for the 36th World Rhythmic Gymnastics Championships, which are due to be held in Sofia from September 10 to 16, will be Maria Petrova.

Considered an icon of Bulgarian rhythmic gymnastics, Petrova belongs to a highly select group of gymnasts who have won three individual all-around world titles.

From 1993 to 1995, Petrova was the queen of the international scene, winning a total of nine world crowns, including five with apparatus and one team.

Russia’s Alexander Moskalenko and Irina Karavaeva will serve as the ambassadors for the 33rd World Trampoline Gymnastics Championships in St. Petersburg from November 7 to 10. 

Moskalenko was the first Olympic men's trampoline champion, courtesy of his triumph at Sydney 2000, and has also set almost every single record on the trampoline bed.

From 1990 until his retirement in 2004 after winning Olympic silver in Athens, he won 18 world medals, 14 of which were gold.

As the winner of five individual titles, Moskalenko continues to set the benchmark for the trampoline discipline.

Like Moskalenko, Karavaeva is a living legend in trampoline and was the discipline's first Olympic women's champion.

No other gymnast has won as many world medals and titles.

Karavaeva has 19 medals, 12 of which are gold, including five individual titles.

Selected as ambassadors for the 26th World Acrobatic Gymnastics Championships, which are scheduled to take place in Antwerp in Belgium from April 13 to 15, are Nikki Snel and Eline de Smedt.

De Smedt and Snel crowned their career by winning gold in the women's pair at the 2014 World Championships, ending five years of competing together in style.

As a country with a long tradition in the sport, their success remains one of the prides of Belgian acrobatic gymnastics.

The ambassadors for the 15th World Aerobics Gymnastics Championships, which are due to be held in Guimarães from June 1 to 6, will be Spain’s Jonatan Cañada and Brazil’s Marcela Lopez.

Cañada has made his mark on aerobic gymnastics for a decade thanks to his originality.

He is one of the discipline's most successful gymnasts with five world titles; individually in 1998, 2000 and 2002, one as part of a mixed pair in 1996, and one as part of a trio in 2002.

Cañada also has two World Games titles, one individually in 2001 and one as part of a mixed pair in 2005.  

Lopez dominated the international individual scene between 2006 and 2010, taking three consecutive world titles plus the World Games crown.

Her one other world title came in 2004, when she was part of a successful Brazilian trio.

Ambassadors will participate in several public events during the World Championships, such as meetings with the public or young athletes.

They will also present the gold medals to the new champions, individually or in their category.

"We are delighted that these major names, who in their own way have each made history in their discipline and influenced their sport, have agreed to act as ambassadors," FIG President Morinari Watanabe said.  

Nellie Kim, herself an artistic gymnastics legend and now vice-president of the FIG and President of the Ambassadors' Commission, added: "We believe that through their very presence, they will help to pass on the passion of this sport to future generations and cast a spotlight on the Worlds, which are our flagship events of the year."