Kickboxing cles go for a cardio or martial art cl…?

Hi, have to complete a health activity cl at college, and took Tai Chi. It is an interesting cl, and encompes some martial art aspect. Though it seems the main goal is to balance the body. I am interested in trying another type of martial arts form. Wondering is there something similar to Tai Chi, but where you can use just your legs. I was thinking about doing a local cardio kickboxing cl, and in combination with another Tai Chi class. Would it be better to look into finding a martial art kickboxing class? Thanks for the response.