Men's Rhythmic Gymnastics (Men's RG, MRG) is an artistic sport which is performed to music on a 13 x13m gymnastic spring floor. It is sometimes called synchronized tumbling, combining the dynamism of powerful acrobatics and perfection of synchronous moves. Athletes are judged on some of the same physical abilities and skills as their female counterparts, such as hand/body/eye co-ordination, but tumbling, strength, and power are the main focus, as well as apparatus handling, flexibility and movements called ""Toshu"" ("freehand"). There are an increasing number of gymnasts, competing alone and on a team; it is most popular in Japan, where high school and university teams compete fiercely. As of 2016, it is estimated there are about 2,000 participants in Japan alone. Some of the outstanding rhythmic gymnasts have made most of their physical abilities for their second careers and become performers in the field of entertainment such as the world-famous circus Cirque du Soleil.