There is a taekwondo gym near Fuxingmen Parkson. There are classes on Saturday and Sunday, and practice classes on Sunday.
I am studying there now. It feels good. The coach is serious. And you can learn a lot.
On the first floor of Xinjiekou Cinema, Liu Qilong's taekwondo class is very good. He is now the coach of Tsinghua. The class atmosphere is very harmonious.