noun
shadowboxing
Boxing training where one fights an imaginary opponent. Used both literally in sports and figuratively for practicing alone or rehearsing arguments.
試合前に、選手は鏡の前でシャドーボクシングをしていた。
Before the match, the boxer was shadowboxing in front of the mirror.
彼は会議の前
Before the meeting, he rehearsed the arguments in his head, like shadowboxing.