What does “сесть на шпагат” mean in Russian?

Сесть на шпагат means “to do the splits,” and the same word шпагат is also thin twine or garden string. The string sense came into Russian through Polish and German from Italian spago, “string.” The gymnastic sense probably has a different source, Italian spaccata, and the two meanings ended up sharing one Russian word.

Russian distinguishes продольный шпагат (front splits) and поперечный шпагат (side splits). Spago is also behind spaghetti, “little strings.” In the clip one of the karate crowd boasts я могу сесть на шпагат без проблем, “I can do the splits, no problem.”