practice swing
Refers to swinging a sword, bat, racket, etc. without hitting a ball or target, as a warm-up or form practice. Common in sports and martial arts.
I take practice swings before stepping into the batter's box.
剣道の稽古で素振りを百回やった。
I did one hundred practice swings in kendo training.
Formed from 素 “without anything added or involved” and 振り “swing,” referring to a swing made without striking a ball or other target.