Getting the junk out

When I was doing tai chi in college I remember Carlos saying that after you do tai chi for a while you could become ill because the tai chi movements help squeeze the lymphatic system which can make them release old junk that is store inside your body. After last class and the class two weeks ago I felt a little ill afterwards and the following day. Are the new movements we've been going over more likely to release junk that's been stored inside the body? I've felt a little like the joints that were worked are a little achy and also inside the abdomen it feels like something is going on.