a place or club where you can go to exercise using machines, weights, and other equipment

I go to the gym twice a week. 我每周去两次健身俱乐部。

You should join a gym.

a large room with equipment for exercising the body and increasing strength, or space for playing sport

We played basketball in the gym. 我们在健身房打了篮球。

physical exercises and activities performed inside, often using equipment, especially when done as a subject at school

gym clothes 体操服

gym shoes 体操鞋

Class 3 do gym on a Wednesday afternoon. 三班周三下午上体操课。

The third graders have gym on Tuesdays and Thursdays. 三年级学生在星期二和星期四有体操课。