I like to rest a muscle group between exercises, too, but there is a certain training logic to overloading the muscles. Supersets, pyramids... it's a pretty common training technique to focus just on a single body part, pushing it to failure. KCM seems to do it a lot in her workouts, plus just about any "parts only" workout (like 10 Minute Solution types, or really, any abs workout).
Workouts that don't... like you mentioned, some of the Firms (but some Firms do stack/superset the muscle groups). I'm pretty sure Cindy Whitmarsh's Ten Days to a Better Body doesn't, but you're also resting the muscles (with cardio intervals) between every move, too.
__________________
~Gem
Dux femina facti
|