Keep fit.

Bodybuilding

Sports, "sports" are sports in a broad sense, and all kinds of sports can be summarized, such as weightlifting, swimming … even stretching your legs and bending over at will. This word is also the expression of "movement" that we first learned from English textbooks.

Work out fitness, the word is "fitness" in the usual sense, which generally refers to doing aerobic, anaerobic and gymnastics stretching exercises in the gym. If you just go out for a run, don't tell others that you are going to work out, just say "I'm going for a run". If you want to meet your friends in the gym after work, you might as well say, "Let's go to the gym after work." . "