I would say swing and salsa are always physically demanding West Coast ? Yeah, really, it depends on how fast the song is and how energetically you react to it. Polka can be pretty demanding. In fact someone asked me to do a swing recenntly, but prefaced it with, "now that you've caught your breath" after I did a pretty fast polka. My milongas have been known to wear out partners. I guess it was more physically demanding for them than for me, and I had more stamina than they did. (I've been told that my long legs/steps can be a challenge. When it comes up I tell partners that they need to signal to me that my steps are too long for them by giving me extra resistance or lagging behind when not in a closed position (not AT.) If you have good technique, why should any dance be "physically demanding?" Physics?