I just did it this morning, and Bayougal and Donna are right. There is one section where you do a big hammering motion, like a stylized (or real) sledgehammering action onto the floor, no impact at all, yet very high intensity. It feels good to do it too.
Also there is a section where you do some kind of punch, then pull back like an archer. That looks and feels good too.
Maybe these moves feel so good to me because I just did Slow and Heavy Shoulders on Monday...
;-) Mmmm, feelin good.