jumping jack

US /ˈdʒʌmpɪŋ dʒæk/
UK /ˈdʒʌmpɪŋ dʒæk/
"jumping jack" picture
1.

开合跳

an exercise in which you stand with your feet together and your arms at your sides, then jump to a position with your legs spread wide and your arms extended overhead, and then return to the starting position

:
We started our workout with 20 jumping jacks.
我们以20个开合跳开始锻炼。
Doing jumping jacks is a good way to warm up.
开合跳是很好的热身方式。